Ward Farnsworth's
Predator at the Chessboard
A Field Guide to Chess Tactics
I: Introduction
The Double Attack
The Discovered Attack
Boo~[
Predator at the Chessboard
A Field Guide to Chess Tactics
Book I: Introduction
The Double Attack
The Discovered Attack
Ward Farnsworth
www.wardfarnsworth.com
Book I: Table of Contents
Introductory Matters
5
I. I. A Short Guide to the Book
5
1.2. Rationale for the Project
6
1.3. The Elements of Tactics: A Primer
9
1.3.1. The Double Threat
1.3.2. The Loose Piece
1.3.3. The Forcing Move
1.3.4. Strategy vs. T actics
9
10
"
I}
1.4. Notation, Jargon, and the Value of the Pie<:es
14
1.5. Acknowledgments and Bibliography
17
1.6. Chess in Literature: Some Interesting Allusions
20
The Double Attack
2.1. The Knight Fork
2.1.1. Introduction
2.1.2. Seeing Potential Forks
2.1.3. The Pinned Guard
2.1.4. Exchanging Away the Guard
2.1.5. Distracting the Guard
2.1.6. Getting Out of You r Own Way
2.1.7. Unsuitable T argets
2.1.8. Playing Defective Knight Forks
2.1.9. Checking the King into Position
2.1.10. Using Mult iple Che<:ks
2.1.11. Using Mate Threats to Force Pieces into Position
2.1.12. Strategic Implications
2.1.13. Sununary
20
20
20
26
29
J2
36
45
48
52
"
69
7J
76
79
2.2. The
Qu~n
Fork
2.2.1. Introduction
2.2.2. Simple Cases: Forking the King and a Loose Piece
2.2.3. Using the Side of the Board During the Opening
2.2.4. Making the Fork ing S-quare Available
2.2.5. Loosening the Target by Exchanging It
2.2.6. Loosening the Target by Disabling its Guards
2.2.7. Moving the Enemy King into Position
2.2.8. Clea ring the Path to the Forking S-quare
2.2.9. Clea ring Paths to the Targets
2.2.10. More Complicated Cases
2.2.11. Using Mate Threats
2.2.12. Mate Threats with Attacks on Underdefended PilX:es
2.2.13. Other Mating Threats
2.2.14. Attacking Two Loose PilX:es
2.2.15. Attacking Two Loose Pieces: More Procedures
2.2.16. The Enemy Queen as a Target
2.2.17. Sununary: Strategic Implications
2.3. The Bishop Fork
2.3.1.
2.3.2.
2.3.3.
2.3.4.
2.3.5.
2.3.6.
2.3.7.
2.3.8.
2.3.9.
Introduction
Bishop Forks One Move Away
Loosening the Forking Square
Loosening the Target and Forking Square
Moving the King into Position, etc.
Bishop Forks of the King and Queen
Bishop Forks of Other Pieces
Playing Defective Bishop Forks
Strategic Implications
81
81
81
87
91
94
%
98
104
108
114
118
127
130
1}3
138
143
147
151
151
154
156
157
159
163
166
171
173
2.4. The Rook Fork
175
2.4.1.
2.4.2.
2.4.3.
2.4.4.
2.4.5.
2.4.6.
2.4.7.
174
178
180
183
186
187
Introduction
Simple Cases
Creating a Target
Moving the King into Position
Clea ring Paths
Working with Mate Threats
Strategic Implications
2.5. The Pawn Fork
2.5.1. Introduction
2.5.2. Exchanges to Create Working Pawn Forks
175
189
189
189
2.5 ..!. Forcing Pieces into Place with Threats and Che-cks
2.5.4. Forks By Marching Pawns
2.5.5. Strategic Implications
The Discovered Attack
3.1. Bishop Discoveries
3.1. I. Introduction to Discovered Attacks Generally
3.1.2. Introduction to Bishop Discoveries
3.1 ..!. The Classic Pattern
3.1.4. The Unmasking Piece Makes a Capture or Threat
3.1.5. Drawing the Enemy King into Place
3.1.6. Drawing the Target into Place
3.1.7. Clearing Needed Lines
3.1.8. Horizontal Discoveries
3.1.9. Introducing the Discovered Check
3.1.10. Removing Impediments to Discovered Checks
3.1.11. The Bishop and Rook Mate
3.1.12. Other Large Threats By the Stationary Piece
3.1.13. Horizontal Discovered Checks
3.1.1 4. Two-steppers: Building the Kernel
3.2. Rook Discoveries
3.2.1. Introduction; Simple Cases
3.2.2. Threatening Mate
3.2.'!. The Rook Discovers Check
3.2.4. Manufacturing Discovered Check
3.2.5. Two-steppers: Building the Kernel
3.2.6. The Windmill
3.3. Knight Discoveries
3.3.1. Diagonal Patterns
3.3.2. Venical and Horizontal Patterns
3.3 ..!. Building Knight Discoveries
3.3.4. Working with Mate Threats
3.3.5. More on Mate Threats: Vertical and Horizontal Patterns
3.3.6. Discovered Check with the Knight
3.3.7. Discovered Checks with Preliminary Exchanges
3.3.8. Discovered Mate Threats
3.3.9. Discovered Check Leading to Mate
3.3.10. Building the Kernel: Diagonal Patterns
3.3.11. Building the Kernel: Venical and Horizontal Patterns
192
197
201
203
203
203
204
205
207
210
212
214
219
223
226
228
231
235
m
241
241
243
247
250
253
257
26l
261
263
266
269
275
277
279
281
283
287
290
Chapter 1.
Introductory Matters.
1.1. A Short Guide to the Site.
Spectacular chess moves produce the same
sorts of satisfactions as the climactic moments
of other great games: the slam dunk, the thirty-foot putt, the home run. In chess these
moves are known as tactics. This web site
teaches them in detail. It assumes you know
only how the pieces move and builds step-bystep from there. Every idea is illustrated with
lots of examples, and every example is explained in plain language that describes a train
of thought leading from a problem to its solution. Funny-looking notation is held to a minimum. You can treat each example as a puzzle
and try to solve it before reading the explanation, or just read the explanations as you go.
The object throughout is to provide a teaching
tool that makes the secrets of chess easy for
anyone to understand. It's a chess book for
people who think they don’t like chess books.
(The site also has a new section—the Chess
Quizzer—that lets you test your understanding by working on positions chosen at random
and with their explanations hidden.)
You can start reading anyplace. The rest of
this first section gives a fuller account of the
idea behind the site and how it differs from
existing books; then comes a primer on the
most important general principles of tactics:
double threats, loose pieces, and forcing
moves (if those terms aren't old hat to you, the
explanations probably will be useful). Last are
some pages discussing further points of interest to some but not others—the notation used
in the diagrams, acknowledgments, how to
change the look of the font, and other miscellany.
If you want to skip any or all of this first part
and plunge into the specific lessons, you can
go back to the table of contents (there’s always a link at the upper right corner of the
screen) and click on The Knight Fork or
whatever other topic sounds appealing. The
sections build on each other a bit, but most of
them can be enjoyed on their own with no
trouble if you prefer to dip in at random or
skip parts that get tedious. If you want to navigate through these early parts or any of the
other sections more precisely, click on the
plus (+) signs in the table of contents to expand each menu. Or click at the top of the
contents page to expand all the menus and see
the entire structure at once (I recommend
this). Or you can flip around by starting anywhere and using the arrows at the bottom of
each screen to go page by page. (Clicking on
the forward (>) arrow at the lower right corner of this page, for example, will walk you
through the rest of this first section.)
This site aspires to be the most detailed and
systematic treatment of basic chess tactics yet
published. It also is meant to be the most congenial to those who like things explained in
English. How far it succeeds, and where it
might be improved, the reader will judge; I
welcome corrections and suggestions, and
apologize in advance for the inevitable typos
or other glitches (and thank those who have
called such mistakes to my attention). All
feedback can be sent by way of the link at the
bottom center of every page.
Let us begin.
1.2. Rationale for the Project.
After this introductory part there are five large
sections, one for each of the great families of
chess tactics: the fork; the discovered attack;
the pin and skewer; the removal of the guard;
and mating patterns. Within those sections are
a total of twenty chapters; within the twenty
chapters are nearly two hundred topics. Each
topic is illustrated with about a half-dozen
positions—occasionally fewer, and sometimes quite a few more.
Why Tactics?
If you have played chess at all, you know it is
easy for the two sides to trade pieces: your
knight takes my bishop, my pawn takes your
knight, and we're even. But if your knight
takes my bishop and I can’t capture your
knight, you gain an edge that probably will be
decisive. If one player has more pieces than
the other, he usually wins without much trouble; between good players, a one-piece advantage is enough to cause the disadvantaged
party to resign. Thus the most important moments in a chess game generally occur when
you take one of your opponent’s pieces and
he gets nothing back, or vice versa.
So how does it happen that one side takes
another side’s pieces for free? Between beginners the common answer is that you wait
for your opponent to blunder by leaving a
piece unguarded, then you just take it―and
hope you aren’t the one to blunder first. Chess
games that go this way aren't terribly interesting, and they make it hard to understand what
all the fuss over the game is about.
The fuss arises because there are moves you
can make that force your opponent to cough
up pieces unexpectedly. All his men look
safe; but then you play a knight fork, a move
in which your knight attacks two of his pieces
at once. He only has time enough (one turn)
to move or protect one of them, so you take
the other for free. It's all very satisfying; and
it's even better when you first capture his
bishop, and he recaptures; then you check his
king, and it moves; and then you play the
knight fork, winning a piece. What makes this
so pleasing is that you've planned the fork and
forced your opponent to step into it by playing a few initial moves that forced his replies.
These sequences―the little clusters of moves
that win your opponent’s pieces―are known,
again, as tactics. A tactical sequence generally
is a short bunch of moves that wins material
(pieces or pawns) or that forces checkmate.
Such a sequence also is known as a combination. (Some people quarrel over the distinction between tactics and combinations. We
won't.)
Now there also are other types of moves you
can make in chess that aren't meant to win any
pieces. Indeed, during a game you often will
have no way to play one of those nifty tactical
sequences, so you instead try to improve your
position: you put your pieces onto squares
where they have more room to move or are
aimed at a part of the board where you are
trying to put together an attack; or you move
your pieces around to fend off your opponent’s attempts to launch attacks of his own.
This sort of play is called strategic. You are
working toward general, long-term goals, and
perhaps laying the groundwork for a tactical
strike of the sort described a moment ago.
When you make these sorts of moves you
may well not be seeing many moves ahead.
You just are arranging your pieces the way
you like, and your opponent is doing the
same. Since you aren’t making any immediate
threats, your opponent is free to go about his
business in ways that may be hard for you to
predict.
Strategy and tactics both are important, but
tactics are more important. If you're a whiz at
finding clever moves that take your opponent’s pieces, you will be a terrifying opponent, have a good time playing chess, and win
lots of games regardless of whether you know
a great deal about strategy. If you're a whiz at
strategy but not much good at tactics, you will
have trouble winning or having fun because
your pieces will keep getting taken. You certainly want to know something of strategy;
you need ideas about what you can do with
your pieces that will create eventual tactical
opportunities for them. We will talk about it
along the way. The point is just comparative:
if you want satisfaction, you had best start by
learning how to play tactics―how to spot and
execute sequences of moves that allow you to
take your opponent’s pieces.
What was said about strategy can be said as
well about openings. You can spend enormous time mastering the details of an opening―say, the Italian Game or the French Defense. The yield of those efforts, in victories
and in fun, probably will be small. You frequently will find that your opponent’s play
drags you away from the opening you studied;
and even if not, the payoff of a successful
opening usually is a minor advantage in position. By itself the advantage will not win you
anything or bring you much pleasure. What
will bring you immense pleasure, whether or
not you know much about openings, is taking
your opponent’s pieces. And to do that you
need to learn how to use tactics―the weaponry of the chessboard.
All this advice assumes you are not a strong
player already. Once the material on this site
all is old hat to you, close study of openings
and subtler points of strategy will make better
sense. One false move in the opening and
your goose is cooked if you are playing Garry
Kasparov; but this is a site mostly for novices,
so if you are reading it you probably should
not be planning to play Kasparov anytime
soon. You should be planning to play others
of at least roughly your own strength ― probably friends who are casual players, or opponents at the local chess club or on the internet. If you keep playing you will move on to
better players, but it still will be a long while
before a deep study of openings really pays
off. In the meantime all of your opponents ―
even the strong ones―will give you plenty of
tactical opportunities; they will commit oversights that allow you to play pretty combinations and win pieces if you are sharp enough
to see the chances for them. Acquiring this
sharpness has nothing to do with memorization. It's a skill you gain by learning what
clues signal that a combination may be possible, and by studying how to turn those clues
into ideas that work.
Its distinctive features can be summarized as
follows:
Why Another Book About Them?
This method of organization makes it easier to
learn in a systematic way about tactics and the
issues that come up in using them. Every idea
is shown in several contexts so that it will
sink in and the persistent features of the pattern become familiar to you. And the many
examples of each complication also will make
it easier to recognize patterns during your
games: you will start to sense that the position
on the board almost resembles a recognizable
pattern and almost lends itself to a known
tactical theme. Then you can experiment with
forcing moves (e.g., checks and captures that
require predictable replies from your opponent) to make it work. The idea guides the
experimentation. But to have the idea in the
first place—to see, for example, that conditions on the board suggest a possible knight
fork, even if the exact means of getting there
has yet to be worked out—you need a repertoire of known tactical patterns that can be
stimulated by the positions you see. The pat-
Since tactics are the most entertaining and
important part of chess, it comes as no surprise that there have been many books written
about them. This site—which amounts to another book, and not a short one—thus requires
a few words of justification. It differs from all
the prior work in several important respects.
Most books about chess tactics follow one of
two patterns. Some describe important tactical
ideas—forks, pins, etc.—and explain their
logic a bit, then provide perhaps a dozen examples of how each tactic works. The other
sort of book presents pages of diagrammed
problems for the reader to solve; the answers
usually are given in the back with minimal
commentary. Both types of books are valuable, especially when used together, but I long
have felt there was a place for a different approach. This project attempts to fill the gap.
Many examples, carefully organized. This site
goes into greater detail than other books do in
explaining each type of tactic and how to
overcome the various obstacles that can arise
in trying to make it work. There are about 80
knight forks here, for example, and they are
broken down according to the different ways
the tactic can look when it is lurking two or
three moves away on an apparently placid
chessboard. It may be that the square your
knight needs is guarded but that the guard can
be taken; it may be that the piece you want to
fork is not very valuable but can be exchanged for a more valuable piece; it may be
that you do not yet have a knight fork but that
after you check the enemy king a forking possibility will come into view. All of these possibilities, and many others, are illustrated with
about a half dozen explanations apiece and
sometimes more. The process is repeated for
all the major tactical motifs: there are more
than 100 queen forks, more than 300 pins,
nearly 200 discovered attacks—all subdivided
into different ways each of these ideas can
look when it is a couple of moves away from
perfection.
terns studied here, in all their little variations,
are meant to go into the reader's store of visual knowledge and become the basis of useful
intuitions and ideas.
Trains of thought explained. Chess tactics
tend to involve the use of certain root ideas—
cognitive riffs—that get repeated and combined in various ways. The explanations here
are meant to explain and reinforce those ideas
so they become a natural part of your thought
process at the board.
This project especially is meant for those who
like explanations in words. Not everyone
does; some students of chess prefer just diagrams with lists of the moves required to
solve them. But I suspect that those who do
think best in words will find it helpful—more
interesting, easier to understand, and more
likely to improve their play—to have the solutions to problems explained out in English.
These are matters of taste, and you, gentle
reader, may not think the world really needs
more words about chess. But if you do share
this sense of mine, and have not found that
most books about chess explain it in a way
that speaks to you or affects your play, perhaps this site will change your relationship to
the game.
Here is a slightly larger statement of the point.
The quality of your chess is determined by the
quality of your train of thought when deciding
what move to make. The train of thought may
be partly verbal, partly visual, or partly intuitive, but in any case it will involve a sequence
in which you consider candidate moves and
their pros and cons. The climb from novice to
something better largely is a move from meandering, unsystematic trains of thought to
more methodical and fruitful ones. For the
beginner it therefore is helpful to see more
than just a list of the correct moves that solve
a chess problem; it helps to hear what questions one might have asked to spot the pattern
and discover the correct moves for oneself.
Thus every example here is accompanied by
commentary explaining not just the right
moves but a train of thought that leads from
the position to its solution.
If you are new to chess, the sequences that
good players use to win games may seem
impossibly complicated. But most of them
actually are based on just a few general concepts combined ingeniously and persistently.
This frame and the ones that follow explain
the concepts broadly. The rest of the site
teaches their use in detail.
The trains of thought offered in the commentaries emphasize the use of clues: signs to
search for during your games that indicate a
tactic might be available. The explanations
show how the same sets of questions, some of
them simple, can generate impressive tactical
ideas when they are asked and answered methodically. Some trains of thought thus are
repeated many times. The repetition would be
inexcusable if the purpose of the project were
just to transmit information, for then once
would be enough. But the purpose is otherwise; it is to help change your mental habits at
the board, and for this purpose an extra measure of clarity and some repetition both are
helpful.
The most important idea in chess is the double threat. Generally speaking a double threat
is any move you make that presents your opponent with two problems at the same time.
Since each player can make just one move per
turn, your opponent only has time to address
one of the threats you have made. On your
next turn you execute the other one. Maybe
your first move checks his king and attacks
another of his pieces at the same time; or
maybe you threaten one of his pieces and are
building a threat of checkmate elsewhere. The
result is the same: your opponent has to spend
his next move dealing with your threat against
his king, and then you get to take the other
piece you were threatening.
1.3. The Elements of Tactics: A Primer.
1.3.1 The Double Threat.
The universe of chess tactics can be divided
into four or five great families of ideas, each
of them a variation on the logic of the double
threat. This site is organized around them:
1. The first family, and the best-known type
of double threat, is the fork — a move where
one of your pieces attacks two enemy pieces
at the same time. You no doubt have seen
examples of knight forks if you have played
chess for a while; the knight naturally lends
itself to moves in which it attacks two pieces
at once. But the same idea can be executed
with your queen or with other pieces, as we
shall see.
2. A second type of double threat, and another
family of tactical ideas, is the discovered attack. This occurs when you move one of your
pieces out of the way of another so that both
of them make separate attacks against your
opponent. Again, he only has time to parry
one of the threats. You play out the other one
on your next move.
3. A third family of tactical ideas involves the
pin or skewer. These occur when two of your
opponent’s pieces are on the same line and
you place an attacker so that it runs through
both of them. In effect you again are making a
double threat—one threat against the piece in
front and another against the piece behind it.
4. And then there are countless other situations that may be lumped under the heading
of removing the guard, in which you capture
or harry an enemy piece that guards something else you want to take. Your opponent
can’t defend against both threats on the one
turn allowed to him, so you are able to play
one of them or the other.
In effect most games of chess are contests to
see who can find a way to use one of those
tactical techniques first. One successful fork
(or discovery, or skewer, etc.) often decides a
game by giving one player an insurmountable
advantage over the other. This is why Richard
Teichmann said that chess is 99% tactics; and
it is why mastery of tactics is the key to having fun at the chessboard, not to mention winning.
[Note: A fifth family of tactical operations
involves mating patterns: characteristic ways
that kings get trapped. These are treated in the
last section of this site. They do not necessarily involve the logic of the double threat in the
way that those tactical devices just described
do. We also are leaving aside a few other,
more minor families of tactics for now.]
1.3.2 The Loose Piece.
Another key idea in chess is the loose piece.
A loose piece is simply a piece that has no
protection. It is common for players to leave
pieces unprotected here and there; as long as
they aren’t being attacked, they look safe
enough. But loose pieces make perfect targets
for the double threats described a moment
ago. Suppose your queen performs a fork,
attacking your opponent’s king and one of his
rooks at the same time. He moves his king.
Now you can use your queen to take his
rook—if it is unprotected. But if the rook is
guarded you won’t be able to take it because
the cost will be too high: your queen will be
captured afterwards.
We can turn this point into advice for practical play. You want to be aware of loose
pieces on the board at all times. Any piece
your opponent has left unguarded is a possible
target for a tactical strike; any piece of yours
that is left unguarded is a vulnerability. Indeed, you want to not only notice loose enemy pieces but also look for ways to create
them. We will see countless examples in the
studies to come. ("Loose pieces" also can be
defined to include enemy pieces that are underdefended: attacked once and defended
once by a fellow piece. As we shall see,
pieces in that condition sometimes can make
targets just as good as pieces with no protection at all.)
The great chess writer Cecil Purdy stated the
point as a rule: "Never leave or place a piece
loose without first looking for a possible fork
or pin, and never see an enemy piece loose
without doing the same." Do you follow this
advice already? Many inexperienced players
don't. When they put a piece onto a new
square, they mostly just check to make sure it
won't get taken there. Purdy's advice is different. It is to ask whether your piece has protection on its new square; and if it doesn't, to ask
carefully whether a fork or pin or other tactic
might be launched against it. You may not yet
understand quite what it means to look for
forks or pins, but you will soon; and then following Purdy's counsel will save you many
sorrows.
1.3.3 The Forcing Move.
Sometimes in chess you do whatever you
want to do and then your opponent does
whatever he wants to do. Other times it’s different: if you capture his knight with your
bishop, for example, he pretty much has to
recapture your bishop; otherwise he simply is
short a piece and probably will lose. (The
other pieces belonging to both sides gradually
will be exchanged away, and you will end up
with the only attacking piece left on the
board.)
Another example: If you check your opponent’s king, he can’t do whatever he wants in
reply; he has to either move the king, block
the check, or capture the piece you have used
to make the threat. And if you make a move
that will enable you to deliver checkmate on
your next turn—a “mating threat”—your opponent likewise will have to address it immediately.
Checks, captures, and mate threats therefore
are known as forcing moves. In other words,
they are moves that force your opponent to
pick from a small set of possible replies. They
are the essence of tactical chess; they allow
you to dictate your opponent’s moves and
thus control how the board will look two or
three or more moves from now. Other types
of moves may be "forcing" as well, mind you:
any threat you make against your opponent—
for example, a simple threat to take one of his
pieces on your next move—may force him to
reply in a certain way. This happens all the
time, and we will see examples as we go. But
checks, captures, and mate threats tend to be
the most interesting and important kind of
forcing moves because they so powerfully
limit your opponent's choice of replies.
This notion of forcing moves helps clear up
some common confusions about chess. No
doubt you have heard about good players seeing ahead five moves, or a dozen moves, or
more; how do they do that when their opponents have so many possible responses to pick
from? The usual answer is that their opponents don’t have so many choices after all.
Suppose I think like this: if I take your knight
with my bishop, you will have to recapture
my bishop; then if I check your king, you will
have to move it over one square; then if I
check your king on its new square, you will
have to block my check; then your rook will
be left loose and I will take it. In this case I
have seen ahead four moves, but notice that I
didn’t have to keep track of a lot of possible
variations. To each of my moves you only had
one plausible reply. I just had to realize this.
Of course sometimes your opponent will have
more than one plausible reply, and in that case
you will need to keep track of some variations
after all (“if he does this, I’ll do that; if he
does the other thing, then I go to plan B,”
etc.). And it’s true that very strong players
can keep straight lots of variations. But it’s
also true that a lot of great tactical sequences
consist entirely of forced moves that make it
not so hard to see ahead.
Once you grasp the idea of forcing moves it
also is easier to understand how to come up
with nifty tactical ideas during your games.
Of course you might like to unleash a fork or
discovery or skewer, but what if no such
moves are possible when it’s your turn? Do
you wait around for a fork to become available? No; your first job when you are deciding what move to play is to examine your
possible forcing moves: any checks, captures,
or mating threats you can offer. You don't
look at these things just as ends in themselves; you ask what moves your opponent
would be forced to make in reply, and
whether you then would be able to play a fork
or discovery or skewer or some other tactic. If
the answer is no, you imagine playing another
forcing move after the first one and then ask
the same questions.
The point of experimenting with forcing
moves, in short, is that they change the look
of the board. They may open up lines that
currently are cluttered; they may cause your
opponent to leave pieces loose that now have
protection; they may make him line up pieces
that are not now on the same line; they may
make him put his king where it can be
checked. Your task is to imagine the board as
it would look after your forcing moves and
see if changes such as those would create tactical openings for you. Gradually a pattern
you recognize may emerge—the makings of a
fork or discovery or other idea.
With practice this becomes second nature: if
your rook is aimed at your opponent’s knight,
you automatically consider capturing the
knight and allowing your rook to be taken.
This would be a sacrifice, of course, since
rooks are more valuable than knights, but
great tactical ideas routinely begin with sacrifices like that. The question is whether the
exchange of your rook for his knight would
leave you with a chance to play a fork or
other double threat—or with a chance to play
another forcing move that isn’t yet possible.
Maybe after your rook is captured you then
can play a check that wasn’t available before;
and maybe after your opponent responds to
the check you then will have a fork. But it all
starts by thinking about a simple capture you
can make and its consequences.
Likewise, you generally don’t want to make
any moves without being aware of any checks
you give and their consequences. Checks are
the most forcing moves of all because your
opponent is required to reply by moving his
king, taking the piece that threatens it, or
moving a piece between them. This usually
makes it easy to see what a check will require
your opponent to do. And since a check often
forces your opponent to move his king, it may
lead directly to tactics that make the king a
target—a fork with the king at one end, or a
pin with a king at the rear, or for that matter
checkmate.
Looking at any checks and captures you have
to offer is like looking for loose pieces on the
board: these are things you do all the time
during a game, because most great tactical
ideas involve one of those elements or the
other.
1.3.4 Strategy vs. Tactics.
Often you will look at your forcing moves
and decide they lead nowhere. That’s fine;
now you instead play a strategic move rather
than a tactical one—a move that improves the
quality of your position without trying directly to win your opponent’s pieces or mate
his king. But strategy and tactics are linked,
since one goal of strategic, “positional” play
is to increase the power of your pieces and
create fertile conditions for tactical strikes on
later moves. Sometimes this is a matter of
arranging your pieces so that they have more
freedom of movement and denying the same
freedoms to your opponent; sometimes it is a
matter of coordinating your pieces so that
they are aimed at the same sector of the
board; sometimes it is a matter of arranging
your pawns to help achieve those same purposes for your pieces. At the end of our study
of each tactical family (and sometimes more
often), we will pause to consider its strategic
implications: what the tactical ideas teach
about the right sorts of moves to play when
there is no such tactic yet available.
All this talk of weaponry admittedly is abstract. It will become concrete in the studies
that follow. We will look at over a thousand
tactical sequences. The rough structure of
most of these sequences, and of a large share
of all the great tactical moves ever played in
chess, is similar; it involves the elements just
described. First there are some forcing
moves—checks or captures or mating threats
that limit your opponent’s replies. Then there
is a denouement: a double threat, such as a
fork or discovered attack or one of the other
themes we will consider, that becomes possible after the forcing moves have changed the
board. As a result you are able to take a loose
or underprotected enemy piece. We can call
this a combination. The variations on this
pattern are limitless, and there is much to
know about its details: how to spot forcing
moves and figure out their consequences, and
how to spot the patterns suggesting that a fork
or pin is in order. You can spend a lifetime
building your understanding of those things
and gaining skill at carrying them out under
time pressure. But as you get started it all may
be more manageable if you consider these
studies as variations on the single idea just
described.
The rest of this introductory section will be
discussing chess notation and jargon, then
some more technical aspects of the site. This
therefore is a good time for a reminder that if
you want to skip any or all of that stuff, perhaps because you already are comfortable
reading about chess positions and want to cut
right to some lessons, you can go back to the
table of contents and navigate from there by
using the link near the upper right corner of
this screen.
1.4 Notation; Jargon; the Look of the Site;
Hard Copies.
1.4.1. Notation and Jargon.
This site makes every effort to explain everything in words, but when describing a series
of chess moves it often is convenient to use
abbreviations to describe them. Those abbreviations are known in chess as notation. This
site generally uses the “algebraic” notation
employed in most chess books, though with a
small difference explained below. Despite the
unpleasant label, it's very easy to understand.
Most of it can be figured out as you read, but
here is what you need to know about how it
works:
1. Squares are named by their coordinates—
a4, e5, h8, etc.; these should be self explanatory, since every diagram includes numbers
running up the side of the board and letters
along the bottom. The numbered horizontal
rows are called ranks. The vertical columns
named by letters are called files.
2. Pieces are named by their first letter. Q =
queen; R = rook; etc. The only exception is
the knight, which is referred to as “N” to dis-
tinguish it from the King (“K”). Pawns are
named by their squares, so that “d4-d5”
means the pawn on d4 moves to d5. Sometimes in this book (and routinely in other
books) a pawn move is described without
bothering to name the square it came from:
one simply says "1. d5," and everyone understands this means that the pawn on the d-file
moves to d5.
3. Captures are described with an “x” between
the names of the pieces capturing and being
captured. So QxB means queen takes bishop;
Rxa5 means the rook captures the pawn on
a5; and h7xN means the pawn on h7 captures
the opposing knight.
This last point is the way that the notation
here varies from the usual algebraic notation
in other books. Algebraic notation normally
describes a capture by just referring to the
square where it occurs. Thus if White’s queen
takes Black’s rook on the f6 square, most
chess books would say “Qxf6”; but on this
site we will say “QxR.” The reason for the
difference is that this site is meant primarily
for people who haven’t read other chess
books before (as noted before, it's a chess
book for people who don't like chess books),
and for that audience the notation used here
will be more intuitive. It's easy to understand
that “QxB” means “queen takes bishop”: easy
to imagine, and easy to find on the board.
“Qxf6,” however, has to be translated into
“queen takes bishop” by looking at the board,
finding f6, and seeing what piece is there.
That’s easy when you know instinctively
where f6 is, but most readers of this project
probably will find it faster to locate the bishop
than to locate f6. The real benefits of naming
captures by the squares where they occur
come when describing long sequences, and
few of the sequences here will be all that
long. (The approach used here is similar to the
one used in Bobby Fischer Teaches Chess, a
well-executed book for beginners.)
This approach to describing captures should
be easy to follow for readers already used to
ordinary algebraic notation; anyone can understand what QxB means even if they are
used to reading Qxf6. The gripe I anticipate
from those who get worked up about these
things is that if readers become used to this
approach they will find it hard to read algebraic notation in other books: they will see,
say, “Qxf6” elsewhere and have trouble remembering that the other author means to say
the queen captures whatever piece is on f6,
not that the queen captures the f6 pawn (as it
will mean here). I regard this as a trivial complaint; the reader of this site who does move
on to other books should have no trouble
making the transition if the above explanation
is kept in mind (or just figuring it out on the
fly; for this explanation makes the whole
business sound more confusing than it is in
practice). It's not that big a deal.
4. Turning back to the notation rules, castling
is indicated by writing 0-0 (if it's on the side
of the board where the king starts) or 0-0-0 (if
it's on the queenside: long castling, as it is
called).
5. Now a couple of minor points that don't
come up often; you probably don't need to
worry about them, but for the sake of completeness: if a capture is made en passant,
that's indicated by writing "ep" afterwards or
some variant. (I'm assuming you know what
an en passant capture is, but if you don't, I'll
explain it if it ever gets used here—and in the
meantime you easily can find an explanation
of it elsewhere on the web.) Second, if one of
your pawns reaches the opponent's back rank,
it gets promoted to some other more powerful
piece of your choice—usually the queen,
though very occasionally some other choice
works better. We indicate promotion with an
equal sign: f7-f8=Q means the pawn on f7
moves to f8 and becomes a queen. Again, I'll
say more about this wherever it pops up.
Finally, if more than one piece could be indicated by a description (in other words, if I
refer to "R" but there are two rooks on the
board and it's not obvious which one is
meant), sometimes the coordinate of the piece
will be given as well. So Rc8xN means the
rook on c8 (not some other rook) captures the
opponent's knight. Occasionally this approach
also will be used just for clarity's sake even if
there is no technical reason for confusion.
6. Sequences of moves are described in pairs,
with the White move first. Thus a game might
begin 1. e2-e4, e7-e5 [again, this could have
been written "1. e4, e5"]; 2. Nf3, Nc6; 3. Bb5,
a7-a6; 4. BxN, d7xB. This means that White
started by moving his e-pawn forward two
squares, and that Black then did the same;
then on White’s second turn he moved his
knight to f3, and then Black moved his knight
to c6. White brought out his bishop. Black
chased it with his pawn on the a-file. White
replied by taking Black's knight. Black recaptured with pawn on c6. The position on the
left illustrates the result.
When we look at positions from the middle of
a game (as we generally will) we will describe White’s first move in that position with
the numeral “1” (as something like “1. Nf5,”
for example). We call it “1” because it’s the
first move in the pictured position, even
though it’s not the first move in the game.
If we want to start by describing a move of
Black’s, we do it by saying something like:
“Black can play 1. …Nf5.” The “1” followed
by the three dots indicates that we’re looking
at the first pair of moves in the position but
that we’re starting with the second half of the
pair: in other words, with Black’s move.
7. A plus sign after a move (like this: Rh8+)
means that the move checks the enemy king.
A "#" sign after a move (like this: Rh8#)
means that the move is checkmate (or simply
“mate,” as we more commonly say).
8. It often happens that a player can sacrifice
a knight or bishop to win an enemy rook.
Since rooks are more valuable than knights or
bishops, a player who does this is said to have
“won the exchange.” If we reach a stage of
the game where I have, say, a bishop and a
rook and you have a bishop and a knight, I am
said to be “ahead the exchange.”
9. A piece is said to be “loose” if it has no
defenders. It is “hanging” if it is exposed to
capture; you hang your queen if you leave it
where your opponent can take it for free. This
also is known as leaving a piece en prise.
1.4.2. The Value of the Pieces.
This site assumes that you know how to play
chess—in other words, how the pieces move.
If you know that much, you probably also
know which pieces are worth more than
which. But to be on the safe side, it is conventional to rank the pieces in the following order
of value, with points given to them as indicated to make it easier to work out whether a
set of exchanges is favorable or unfavorable:
If you use Mozilla’s Firefox browser, you
likewise can fiddle with Tools …Options
…Fonts & Colors. Check "Always use my
fonts"; then set your preferred font elsewhere
in that same window. The Microsoft browser
produces slightly better results for some people (sorry!), but it may depend on what sort of
monitor you use.
If none of this helps, please let me know. I'm
still working on making the type easy to read
on every computer screen.
Queen = 9
Rook = 5
1.4.4. About the Dinosaurs.
Bishop = 3
Knight = 3
Pawn = 1
1.4.3. Making the Site Easier to Read.
First of all, the site is best viewed at a resolution of at least 1024 x 768. Anything smaller
will force you to use a slider bar to read the
pages: no fun at all. My apologies to those
who don't have such an option, but the majority of all monitors nowadays can achieve this,
and it makes for the best reading environment.
If the size of the type on this site, or the
spaces between the lines, aren’t to your liking,
you should be able to adjust them in the usual
way (hit CTRL and then use the scroll button
on your mouse; or use the “View” menu on
your browser). If you are having trouble getting satisfactory results this way, you may
find it useful to disable the site’s automatic
formatting. On Microsoft’s Internet Explorer
you do this by going to Tools… Internet Options… Accessibility… and then checking the
boxes to ignore the font styles or sizes (or
both) specified on web pages. Then set your
own font (still on the Internet Options page)
and play again with the browser’s type size
settings (under the View menu).
This site is titled Predator at the Chessboard,
and is decorated with dinosaurs; yet the dinosaurs pictured are herbivores. Is this not a
contradiction of some sort? In fact it isn't; and
this, patient reader, for two reasons.
First, if you unexpectedly were to encounter a
Stegosaurus or a Triceratops—such as, perhaps, the handsome one shown to the left—
you yourself would regard it as a decidedly
formidable predator, would you not? But second and more to the point, the complaint
about the dining habits of the pictured dinosaurs reflects, I say, a failure of perspective
and imagination; for you too hastily are assuming that they are the predators. Has it occurred to you that they are the prey, and that
you are the Tyrannosaurus (or, perhaps, the
Allosaurus) intending to dine on them? That
is the sort of thinking this site means to encourage. After reading it for a while, situations that formerly caused you to react with
dread and an instinct for defense and retreat
will instead inspire you to think by habit—
aye, and with relish—about making a meal of
your opponent.
Either that, or plants make underrated prey;
but Herbivore at the Chessboard didn't have
the same ring to it.
Onward.
1.4.5. Hard Copies.
Many readers of the site have written to ask if
the material it contains is available in hard
copy. Now it is; there are links at top of the
front page. These are oversized paperbacks,
and they contain every position and discussion that appears in the online version: over
700 pages in total, with over 1,000 illustrations and commentaries. I hope they will be a
convenience to those who prefer reading
books to reading screens. Hardcover versions
are available, too; you can find them by
searching at www.lulu.com, which is where
the links on the front page will take you anyway. At the lower left of the publisher's site,
you can ask to have the prices displayed in
pounds or euros if you prefer.
Second—in alphabetical order only—is Tim
Feinstein, a wonderful chessplayer and terrific
lawyer who read the manuscript. He caught
many mistakes and made a lot of great suggestions. (Many errors no doubt remain here
and there. He isn’t responsible for them.) Tim
is a generous teacher from whom I have
learned much about the game, and I thank him
profusely. In everyday life he is far kinder
than he appears in this picture, which captures
him in a moment of characteristic brutality
toward an opponent. You wouldn't want to
cross him at the chessboard.
1.5 Acknowledgments and Bibliography.
I now wish to thank two gentlemen, each of
whom has lent a bit of his genius to this project.
The first is Alon Cohen, the builder of this
site, pictured to the left. He is a man of surpassing energy, generosity, and creativity, and
I hope you will share my judgment that he has
done a beautiful as well as a functional job.
We collaborated on the design; anything you
don’t like about it safely can be blamed on
me, while the good parts almost certainly
were his idea.
Tim Feinstein
Bibliography.
One of the goals of this project is to take
every problem that commonly arises in tactical play and illustrate its handling with a half
dozen or so progressive illustrations. To find
the positions needed for the purpose—roughly
1,200 in all—I drew on just about every
source I could find. I list them below, and
thank their authors (and beg the pardon of any
I may have neglected to mention). I have
learned from all of them. There are a few
notes at the end about some particular titles.
Alburt, Chess Training Pocket Book (1997)
Ault, The Chess Tutor (1975)
Bain, Chess Tactics for Students (1993)
Alon Cohen
Blokh, The Art of Combination (1994)
Blokh, Combinational Motifs (1998)
Lein and Archangelsky, Sharpen Your Tactics! (1996)
Blokh, 600 Combinations (2001)
Littlewood, Chess Tactics (1984)
Burgess, The Mammoth Book of Chess (1997)
Livshitz, Test Your Chess IQ (1981)
Chandler, How to Beat Your Dad at Chess
(1998)
Chernev, Combinations: The Heart of Chess
(1960)
Chernev, Logical Chess: Move by Move
(1957)
Neishtadt, Test Your Tactical Ability (1981)
Neishtadt, Your Move! (1990)
Palatnik and Alburt, Chess Tactics for the
Tournament Player (1995)
Polgar, Chess (1994)
Chernev and Reinfeld, Winning Chess (1948)
Pongo, Tactical Targets in Chess (2000)
Emms, The Ultimate Chess Puzzle Book
(2000)
Fischer et al., Bobby Fischer Teaches Chess
(1966)
Purdy, The Search for Chess Perfection
(1997)
Reinfeld, 1001 Brilliant Ways to Checkmate
(1955)
Furst, Theme Artistry (1987)
Gillam, Winning At Chess (1994)
Gillam, Your Move (1994)
Harding, Better Chess for Average Players
(1996)
Hays, Combination Challenge (1991)
Hays, Winning Chess Tactics for Juniors
(1994)
Horowitz, How to Win in the Chess Openings
(1951)
Reinfeld, 1001 Winning Chess Sacrifices and
Combinations (1955)
Renaud and Kahn, The Art of the Checkmate
(1953)
Robertie, Winning Chess Tactics (1996)
Seirawan and Silman, Winning Chess Tactics
(1995)
Tal, Tal-Botvinnik 1960 (1970)
Vukovic, Art of Attack in Chess (1998 ed.)
Walker, Chess Combinations (1999)
Horowitz and Reinfeld, First Book of Chess
(1952)
Ivaschenko, The Manual of Chess Combinations (1997)
Koltanowski and Finkelstein, Checkmate!
(1998)
Koltanowski and Finkelstein, Checkmate
Strategies (1999)
Weeramantry, Best Lessons of a Chess Coach
(1993)
Wilson and Albertson, 303 Tricky Chess Tactics (1999)
Znosko-Borovsky, The Art of Chess Combination (1959)
Some positions also have appeared in Shelby
Lyman’s chess column in the Boston Globe or
in Riga’s Chess magazine.
A few notes on these:
1. The books by Reinfeld and Hays probably
are the best collections of positions to solve if
you are looking for practice (a number of positions from those books are discussed here);
Livshitz and Gillam also are excellent for that
purpose, as is the book by Lein and Archangelsky.
2. Among books that offer instruction in
words, I suggest Chernev and Reinfeld's Winning Chess, Ault's The Chess Tutor, and Seirawan and Silman's Winning Chess Tactics.
(The first two may be hard to find, but are
worth the trouble.) Many of the others are
excellent, too, and I don't mean to slight any
of them by mentioning these three. Of course
those books fill a somewhat similar niche to
this site; for those who are reading this, they
are my competition. But I encourage you to
check them out and make comparisons. Different people learn better from different writers.
3. The titles by Renaud and Kahn and by
Chandler are terrific sources on mating patterns; so are the Koltanowski and Finkelstein
books, which are overlooked. Again, many
positions in the "mating patterns" section of
this site are drawn from those sources.
4. For the reader looking to move on to the
study of strategy, I especially recommend
Chernev's Logical Chess and Nunn's Understanding Chess, both of which walk you
through chess games and explain the strategic
(as well as tactical) thinking behind the
moves. My other favorite titles on strategy are
Jeremy Silman's The Amateur's Mind, How to
Reassess Your Chess, and (perhaps most useful of all) The Reassess Your Chess Workbook, which is full of excellent examples and
discussion. Seirawan and Silman's Winning
Chess Strategies is another fine overview you
may find helpful. Everyone's Second Chess
Book by Dan Heisman also has a wealth of
tips on strategy as well as other topics; Heis-
man offers a number of good online resources
as well.
5. And for the reader simply looking for good,
lively writing about chess, I suggest checking
out any of the writings of C.J.S. Purdy, starting with the one referenced above. He is
magnificent.
1.6 Chess in Literature.
Some Interesting Allusions to Chess.
Fielding, Joseph Andrews (1742):
But human life, as hath been discovered by
some great man or other (for I would by no
means be understood to affect the honour of
making any such discovery), very much resembles a game at chess; for as in the latter,
while a gamester is too attentive to secure
himself very strongly on one side the board,
he is apt to leave an unguarded opening on the
other; so doth it often happen in life, and so
did it happen on this occasion; for whilst the
cautious constable with such wonderful sagacity had possessed himself of the door, he
most unhappily forgot the window.
Fielding, Life of Jonathan Wild the Great
(1743):
How impossible for human prudence to foresee and guard against every circumvention! It
is even as a game of chess, where, while the
rook, or knight, or bishop, is busied forecasting some great enterprize, a worthless pawn
exposes and disconcerts his scheme.
Boswell, Life of Johnson (1791):
There is one circumstance in Sir John's character of Bishop Still, which is peculiarly applicable to Johnson: “He became so famous a
disputer, that the learnedest were even afraid
to dispute with him; and he finding his own
strength, could not stick to warn them in their
arguments to take heed to their answers, like a
perfect fencer that will tell aforehand in which
button he will give the venew, or like a cunning chess-player that will appoint aforehand
with which pawn and in what place he will
give the mate.”
Dickens, Bleak House (1853):
He is clear that every such person wants to
depose him. If he be ever asked how, why,
when, or wherefore, he shuts up one eye and
shakes his head. On the strength of these profound views, he in the most ingenious manner
takes infinite pains to counterplot when there
is no plot, and plays the deepest games of
chess without any adversary.
sane, but extremely business-like; and if
Shakespeare ever really held horses, it was
because he was much the safest man to hold
them. Imagination does not breed insanity.
Exactly what does breed insanity is reason.
Poets do not go mad; but chess-players do.
Stoker, Dracula (1897):
So be it that he has gone elsewhere. Good! It
has given us opportunity to cry 'check' in
some ways in this chess game, which we play
for the stake of human souls.
James, The Figure in the Carpet (1896):
Orwell, Homage to Catalonia (1938):
The figures on the chessboard were still the
passions and jealousies and superstitions and
stupidities of man, and their position with
regard to each other, at any given moment,
could be of interest only to the grim, invisible
fates who played the game – who sat, through
the ages, bow-backed over the table.
What purpose is served by saying that men
like Maxton are in Fascist pay? Only the purpose of making serious discussion impossible.
It is as though in the middle of a chess tournament one competitor should suddenly begin
screaming that the other is guilty of arson or
bigamy. The point that is really at issue remains untouched.
Churchill, The People’s Rights (1909):
Moves are made upon the scientific and strategic boards, advantages are gained by mechanical means, as a result of which scores of
millions of men become incapable of further
resistance, or judge themselves incapable of
further resistance, and a fearful game of chess
proceeds from check to mate by which the
unhappy players seem to be inexorably
bound.
Roosevelt, The Conditions of Success (1910):
There are exceptional cases, of course, where
there is a man who can do just one thing, such
as a man who can play a dozen games of
chess or juggle with four rows of figures at
once—and as a rule he can do nothing else.
Chesterton, The Maniac (1908):
Poets are commonly spoken of as psychologically unreliable; and generally there is a
vague association between wreathing laurels
in your hair and sticking straws in it. Facts
and history utterly contradict this view. Most
of the very great poets have been not only
Oliver Wendell Holmes, Sr., The Autocrat of
the Breakfast Table (1858):
The whole force of conversation depends on
how much you can take for granted. Vulgar
chess-players have to play their game out;
nothing short of the brutality of an actual
checkmate satisfies their dull apprehensions.
But look at two masters of that noble game!
White stands well enough, so far as you can
see; but Red says, Mate in six moves;—White
looks,—nods;—the game is over. Just so in
talking with first-rate men; especially when
they are good-natured and expansive, as they
are apt to be at table.
Oliver Wendell Holmes, Sr., The Poet at the
Breakfast Table (1872):
Men's minds are like the pieces on a chessboard in their way of moving. One mind
creeps from the square it is on to the next,
straight forward, like the pawns. Another
sticks close to its own line of thought and
follows it as far as it goes, with no heed for
others' opinions, as the bishop sweeps the
board in the line of his own color. And an-
other class of minds break through everything
that lies before them, ride over argument and
opposition, and go to the end of the board,
like the castle. But there is still another sort of
intellect which is very apt to jump over the
thought that stands next and come down in
the unexpected way of the knight. But that
same knight, as the chess manuals will show
you, will contrive to get on to every square of
the board in a pretty series of moves that
looks like a pattern of embroidery, and so
these zigzagging minds like the Master's, and
I suppose my own is something like it, will
sooner or later get back to the square next the
one they started from.
solitaire with the members of your own family for pegs, if you like, and if none of them
rebel. You can play checkers with a little
community of meek, like-minded people. But
when it comes to the handling of a great state,
you will find that nature has emptied a box of
chessmen before you, and you must play with
them so as to give each its proper move, or
sweep them off the board, and come back to
the homely game such as I used to see played
with beans and kernels of corn on squares
marked upon the back of the kitchen bellows.
Oliver Wendell Holmes, Sr., Ralph Waldo
Emerson (1891):
We often move to the objects of supreme curiosity or desire, not in the lines of castle or
bishop on the chess-board, but with the
knight's zigzag, at first in the wrong direction,
making believe to ourselves we are not after
the thing coveted.
Inherited qualities move along their several
paths not unlike the pieces in the game of
chess. Sometimes the character of the son can
be traced directly to that of the father or of the
mother, as the pawn's move carries him from
one square to the next. Sometimes a series of
distinguished fathers follows in a line, or a
succession of superior mothers, as the black
or white bishop sweeps the board on his own
color. Sometimes the distinguishing characters pass from one sex to the other indifferently, as the castle strides over the black and
white squares. Sometimes an uncle or aunt
lives over again in a nephew or niece, as if the
knight's move were repeated on the squares of
human individuality. It is not impossible,
then, that some of the qualities we mark in
Emerson may have come from the remote
ancestor whose name figures with distinction
in the early history of New England.
Oliver Wendell Holmes, Sr., Over the Teacups (1890):
Life is a very different sort of game. It is a
game of chess, and not of solitaire, nor even
of checkers. The men are not all pawns, but
you have your knights, bishops, rooks,—yes,
your king and queen,—to be provided for.
Not with these names, of course, but all looking for their proper places, and having their
own laws and modes of action. You can play
Oliver Wendell Holmes, Sr., The Guardian
Angel (1867):
Oliver Wendell Holmes, Sr., The Guardian
Angel (1867):
With most men life is like backgammon, half
skill, and half luck, but with him it was like
chess. He never pushed a pawn without reckoning the cost, and when his mind was least
busy it was sure to be half a dozen moves
ahead of the game as it was standing.
Chapter 2:
The Double Attack.
2.1. The Knight Fork.
2.1.1 Introduction.
Dg001: Black to move
Dg001: We begin our study of tactics with
double attacks, or forks: moves that attack
two enemy targets at once.
And we begin our study of double attacks
with knight forks. In the skeletal diagram to
the left, White’s knight has forked Black’s
king and rook; in other words, it attacks them
at the same time.
Why start with the knight? Because it is an
especially vicious and common forking tool.
First, it can threaten a wide range of targets.
The knight is roughly comparable in value to
a bishop, and so is less valuable than a rook or
queen; thus a knight not only can attack any
unprotected (or “loose”) enemy pieces but
also can be exchanged favorably for enemy
queens and rooks regardless of whether they
have protection. Second, the knight’s unique,
non-straight pattern of movement creates two
advantages: it allows a knight to attack other
pieces without fear of being captured by
them; and it enables a knight to make jumps
and deliver threats that are surprising to the
eye and so are easy to overlook.
To spot possible knight forks you will want to
become habitually aware of the relationships
between your knights and your opponent’s
pieces (and between his knights and your
pieces), especially as the knight progresses up
the board. Every rank a knight moves forward
tends to bring it closer to forking targets, especially the king; notice that once your knight
reaches its fourth rank, it can attack your opponent’s back rank, and often his king, in one
move (thus in the diagram to the left, White’s
knight might have been on e4 a move earlier—seemingly pretty far from Black's king).
Hence the strategic importance of planting
knights on central and advanced squares, and
the tactical importance of constantly looking
for forks your knight might be able to deliver
once it is properly developed.
The difficulty in fashioning a fork, of course,
is that no matter where your knight sits you
rarely will find a fork lying one move away
against a decent player. Leaving two pieces to
be forked by a knight on the next move is a
blunder almost as bad as leaving a piece
hanging outright. Forks have to be manufactured; the challenge is to see when one lies a
few steps away. Fortunately knight forks a
few steps away come in a finite number of
types that you can learn to search for systematically and, with practice, recognize quickly.
Such situations can be sorted into two general
types.
Dg002: White to move
Dg002: First, sometimes two of your opponent’s pieces sit on squares that can be forked
with one move of your knight, but there is
some obstacle to your taking advantage of
this; most commonly, the square your knight
needs to reach—call it the “forking square”—
is defended by your opponent (the diagram to
the left shows such a case, again in skeletal
form; White would like to play the fork Nf6+,
but he can't; the f6 square is defended by a
pawn). We will refer to these as cases where
you have a potential fork—a move that
amounts to a fork on its face, but that needs to
be perfected by overcoming some defensive
measure that your opponent has in place. In a
moment we will catalogue those defensive
measures and how to deal with them.
Dg003: White to move
Dg003: Second, sometimes you will not have
even a potential fork because your opponent’s
pieces are not arranged for it; there are no two
enemy pieces that your knight can attack in
one move. Thus in the diagram to the left,
White cannot deliver a fork, but he could if he
were able to get Black’s king to move over a
square onto g8. In cases like this it sometimes
is possible to draw enemy pieces onto forkable squares with some forcing moves—most
often with a check or two. Later we will consider the clues that such possibilities for manipulation may exist and how they can be
brought to fruition.
2.1.2. Seeing Potential Forks.
Dg004: White to move
Dg004: Let's begin with ways of perfecting
potential forks—in other words, cases where
your opponent starts with two pieces that at
least are on forkable squares. The first important thing is to see all such forks in the first
place. It helps to start by learning to spot all
of a knight’s possible moves at a glance. For
this purpose you will want a clear mental picture of the ring of eight squares that are the
maximum to which a well-placed knight can
move. In the diagram on the left, the White
circles show squares where the White knight
can jump, and the Black circles show squares
where the horribly positioned Black knight
can jump. Now you can understand why having your knight near the edge of the board
generally is bad policy: it can’t reach—and
thus can’t control—many squares from there.
Study these visual patterns so that seeing a
knight’s moves from any position comes easily to you.
Dg005: Black to move
Dg005: Now to the matter of spotting knight
forks in particular. You may be used to certain
forking patterns: your opponent’s king and
rook are a square apart on his back rank, inviting you to fork them. But it takes more care
never to overlook a potential fork when the
board is crowded and the pieces to be forked
are not lined up so neatly on the same row.
Consider the opportunities here for Black’s
knight on b7. By moving to c5 it can fork four
White pieces (find them); by moving to d6 it
can fork two pieces. Whether either of these
forks "work" is another question (the squares
the knights need are guarded, though Black
has possible replies, etc.), but don't worry
about that now. It's just an exercise in geometry: we want to see everyplace where two
White pieces are in a forkable position. Seeing only the obvious forking candidates is no
good, and won’t lead to tactical magic. If they
are obvious your opponent can see them, too,
and can avoid them. You want to see all of
the possibilities every time they exist.
Notice an important feature of the knight's
movements: every time a knight moves it
lands on a different colored square. This can
be used to make your searching more efficient. It means that two pieces can be forked
by a knight only if they are on squares of the
same color; it means that they only can be
forked by a knight that lands on a square of
the opposite color; and it therefore means that
if a knight is in position to deliver a fork on
its next move, the knight and its targets must
all then be sitting on squares of the same
color. This is a valuable idea; consider it a
law of knight forks.
To state the practical implication plainly, one
way to build your ability to see all the potential knight forks on the board is to look for
any two pieces of your opponent’s that are on
squares of the same color as the square where
your knight sits. If, as in this case, your knight
is on a light square, scan the board for pieces
of your opponent’s also on light squares. Can
any two of them be forked by your knight?
This only takes a moment; you aren’t yet analyzing whether any of the forks would work,
but just are reviewing the board visually for
simple patterns—a color scan. Sometimes this
will be a helpful way to alert yourself to forking opportunities; in other positions it will be
more efficient just to look directly at your
knight moves without reference to square
color. Experiment.
Dg006: White to move
Dg006: As you do your scanning you will
discover certain additional laws of knight
moves that will become part of your visual
vocabulary. An important example is that two
pieces can't be forked if they are on the same
diagonal with one square between them. Thus
the Black king and queen in the diagram to
the left are on squares of the same color, but
there is no square from which a knight would
be able to attack them both. This is a familiar
pattern, and when you see it you will not need
to pause to think about whether a knight fork
is in the immediate offing; the sight of it will
be self-explanatory, and you will move on.
Similarly, if your knight is on the same diagonal as an enemy piece and separated from
it by one square, the knight is three moves
away from being able to attack the piece.
Thus in the diagram the White knight is three
moves from being able to attack the Black
king; it must move, say, to e4, then to g5, then
to e6.
Another useful thing to know is that a knight
may be able to attack an enemy target two
different ways—but never more than two. In
the diagram, for example, White's knight can
attack the Black rook by moving to e4 or d5
(and only the latter move creates a fork). This
is useful to remember because the first attacking idea you see with your knight may turn
out not to be the best one—even against the
same enemy piece.
Practice broad-mindedness when you scan for
forking prospects. It is especially important
not to dismiss a possible fork automatically,
perhaps half-consciously, when you notice
that the square your knight needs is protected
by a pawn, or when you see that the fork
would involve your opponent’s king on the
one hand but a knight or protected pawn on
the other. In the latter case you might quickly
imagine that if you tried the fork the enemy
would move his king and the pawn would not
be worth taking, and so write off the forking
prospect without taking it seriously. But that
train of thought is premature; great combinations often look just that way at first. You
want to separate the creative process of seeing
that the geometry is there for a fork from the
editing process of analyzing whether the fork
can be made profitable. Much of the rest of
this chapter is devoted to the editing process:
how to take potential forks that look defective
and turn them into tactical shots that work.
But all along you also want to build the visual
habit of noticing every time your knight can
attack two sensitive points at once, no matter
how implausible the attack looks at first.
2.1.3. The Pinned Guard.
When you see a possible knight fork, a natural
first question is whether the square your
knight needs is protected by any of your opponent’s pieces. If it is, your attention turns to
the guard of the square and whether you can
get rid of it—or whether you really need to
get rid of it. Perhaps you don't; maybe the
protection that the piece appears to offer is an
illusion, as is the case if the guard is pinned.
A piece is pinned if it can't move without exposing the king or another valuable piece to
attack. Indeed, a piece that screens its own
king from attack is subject to an “absolute”
pin and so cannot legally move. We will study
pins in detail in later chapters, but this much
is enough to help you see that sometimes a
square that looks well-defended really isn't.
Dg007: Black to move
Dg007: So here is our method in this section:
consider the piece that protects the square you
want to occupy—we can call it the guard of
the forking square—and see what other pieces
may be on the same line with it and thus exposed to attack if it moves. Start with the diagram. There is a knight fork waiting for Black
with Nf2; the placement of White's king and
queen with three squares between them on the
first rank is a classic setup for a double attack.
If that isn't yet obvious to you, notice that
your knight is on a light square and that
White's king and queen (not to mention several other pieces) are on light squares as well,
which encourages a look at whether you can
fork any of them. Having found Nf2 one way
or another, ask: is f2 protected? It seems to
be, by the White rook at f3; so study the rook
more carefully. It's on the same line with its
king, and with your queen. This means that if
the rook moves it will expose its king to attack—which is to say that the rook can't legally move at all. So Nf2+ can be played with
impunity, and it wins the queen after White
moves his king.
Dg008: White to move
Dg008: Our modus operandi is to look for
double attacks with the knight and ask
whether they can be made to work. This time
you're playing the White pieces. Notice first
here that your knight is on a dark square; now
look for Black pieces also on dark squares.
You find the Black rook and king, and ask
whether they can be forked. They can, with
Nd5+. Now ask: Is d5 protected? Yes, by the
pawn at c6. But before worrying further you
examine the pawn to see if it is constrained. It
is; it’s pinned to the king by the White rook at
a6. So Nd5+ is safe, and it forks and wins the
Black rook. This position is structurally about
the same as the previous one.
Dg009: White’s most advanced knight (generally the one you want to examine first) is on
a light square. Again you might just look for
knight moves, or you might look for forking
candidates by scanning for Black pieces also
on light squares, and find many—both of his
knights, one of his bishops, one of his rooks,
and his king.
sequence. His bishop back on g5 now is attacked twice and defended only once. Does he
lose it? No—but only because once his knight
ends up on b7, it attacks Black’s queen. Now
if Black plays BxB, White has NxQ. Black
therefore needs to spend his next move taking
his queen out of danger, and White’s fork
works after all. The general lesson: be mindful of the defensive work your pieces are doing before you send them off to attack.
Dg009: White to move
Nd6+ forks Black’s king and b7 bishop; the
bishop is unprotected—is “loose”—making it
a good target. The next question is whether
the square you need (d6) is protected. It is, by
Black’s bishop at e7. But then consider how
the board would look if the bishop moved to
d6 to take the knight. See that Black’s queen
would then be taken by White’s bishop at g5;
in other words, Black’s bishop is pinned to his
queen. Nd6+ thus wins Black’s b7 bishop
without fanfare.
There is another point to consider here. You
want to think not just about what your tactical
moves will achieve in the way of material
gains, but also about how the board will look
after the sequence you want to play. This
point applies to all tactical operations; we will
encounter it constantly. The important point
here involves the work that your e4 knight is
doing before it is sent off to inflict a fork. It's
guarding the bishop on g5. To be more precise, at the start of the pictured position the
bishop is protected twice (by White’s two
knights) and attacked twice (by Black’s
bishop and the queen behind it). The bishop
therefore was safe: if Black captured it, White
would recapture; if Black captured again,
White would recapture again. But when
White sends his knight off from e4 to d6, the
bishop loses one of its guards. While this
doesn’t matter so long as White is keeping
Black busy with checks, notice the hazard that
arises once White plays NxB at the end of the
Dg010: Black to move
Dg010: Black’s knight is on a dark square. So
are several of White’s pieces, most usefully
his king and e1 rook, which can be forked
from f3. But notice as well that f3 appears to
be protected by the rook on e3. So examine
the rook and its freedom of movement, playing through its move and what would then be
possible in your mind’s eye. If 1…Nxf3+; 2.
RxN—and then Black can play RxRe1.
White’s queen wouldn't then be able to recapture at e1 because Black would have a second
rook still trained on the square. The point:
White's rook on e3 is pinned—not to its king,
but to the other rook at e1. One way or another Black gains a pawn and the exchange.
(Capturing a rook in return for a bishop or
knight is known generally as “winning the
exchange.”)
Dg011: Here is an important twist. Black’s
most advanced knight is on a dark square. So
are White’s queen, king, and rook, with the
latter two pieces subject to a fork at c2. But c2
appears to be protected by White’s queen.
by White’s queen. Ne6+ thus wins the queen
without further ado.
Dg013: With White’s knight and Black’s king
and queen all on light squares, conditions
seem right for a fork on f6. Is the square protected? Yes, by the Black bishop on e7. If
White tries to first capture it with his own
bishop, then Black recaptures with his queen
and the fork is ruined.
Dg011: Black to move
The queen is not constrained by a pin—yet.
But examine the fork by actually playing it in
your mind’s eye, imagining the knight on c2
and not on b4. When you so imagine a move
or exchange, pay attention to what lines are
opened and closed by it and what consequences may follow—especially new pins and
new possible checks.
In this case, once the knight moves the White
queen is pinned by Black’s queen. So play
goes 1. …Nc2+; 2. Kf1, QxQ (without this
intermediate step, all is lost; do you see
why?); 3. NxQ, NxR. This time the lesson is
that you do not just ask whether the troublesome piece currently is pinned; you ask, too,
whether it would be pinned if you made the
forking move.
Dg013: White to move
But again the trick is to imagine the fork,
mentally placing the knight on f6 and not on
e4. Then you can see that once the knight
moves, the Black bishop becomes pinned to
Black’s queen by White’s queen—another
“discovered” pin. The point repeats: don’t just
ask whether moves are possible; picture
moves, visualize whatever countermoves
seem to make them impossible, and ask what
would then be possible if the countermoves
were made.
2.1.4. Exchanging Away the Guard.
Dg012: White to move
Dg012: A similar problem. White’s knight is
on a dark square. So are Black’s king and
queen. A fork is indicated at e6. The square
appears to be protected by the pawn at d7, so
look more closely; imagine the knight moved,
and observe that the pawn then will be pinned
Now let’s assume an enemy piece guards the
square your knight needs, and it isn't pinned.
Perhaps you nevertheless can get rid of it.
Sometimes the guardian of the forking square
may be captured: you can take it, and the
piece that recaptures yours no longer will protect against the fork.
Dg014: The position of Black’s king and rook
make the idea for White clear enough: Nf7+.
But f7 is protected by Black’s knight. Ask if it
can be captured, and see that it can be―with
White’s rook. After playing RxN, White loses
the rook to f6xR; but he regains it with the
fork Nf7+, capturing Black’s rook next move
and leaving White a knight to the good.
Dg015: Again one of White’s knights is pretty
far advanced up the board on f5; any knight
planted on the fourth or fifth rank is a constant forking threat. So White does a quick
scan for forks and observes that the knight is
on a light square along with Black’s king and
queen―which can be forked with Ne7+. The
needed square is protected by one piece: the
bishop on d6, but White can take out the
bishop with his rook now on d1. So White
picks up a piece, and if Black recaptures
White can follow up with the fork: 1. RxB,
c7xR; 2. Ne7+.
Dg014: White to move
Remember when you play a capture that your
opponent may not be required to recapture.
Usually that will be his choice, but in principle he also may be able to make some other
capture or counterthreat of his own. Here
Black can reply to White’s RxN by playing
RxN himself. Doesn't this end the forking
threat? It does, but at a prohibitive price; for
then White has Re8#—a classic back rank
mate that takes advantage of the way Black's
king is stuck in the corner. At the outset of the
position the Black rook on d8 is the only
piece protecting against this mating threat, so
it can't afford to leave its post. We will study
back rank mates in detail at various points
later in this project (they get a section to
themselves toward the end).
Dg016: White to move
Dg016: The thought process is identical:
White examines his knight’s moves, or perhaps does a color scan and notices that his
knight and Black’s king and queen all are on
dark squares; one way or another there is a
potential fork in Nd7+. The hindrance is that
the bishop at c8 protects the needed square.
Can White capture the bishop? Yes, with his
queen—a sacrifice worth making for the fork
that follows. So White picks up a piece, and if
Black recaptures White can follow up with
the fork: 1. RxB, c7xR; 2. Ne7+.
Dg015: White to move
Dg017: White to move
Dg017: Your most advanced knight is on a
light square, as are Black’s king and queen;
there is a potential fork at e7. Ask if the
square is safe, and see that it is guarded by the
bishop at d6. Now look for pieces you can use
to attack the bishop and notice the queen at
d1―but also the knight at c4. It is important
to notice both. The question is not “do you
have a piece attacking X?” It’s “how many of
your pieces—plural—attack X?” You don't
want to sacrifice your queen when a knight
will do, especially as it would make the sequence a wash, Correct is 1. NxB; c7xN; 2.
Ne7+.
When you capture the f7 pawn at the beginning, you should not assume that your opponent necessarily has to recapture the way you
would like. He might prefer to let the pawn go
rather than play into your hands; it depends
on the quality of his alternatives. Here Black
has the option of replying to Rxf7+ with Kg8,
which loses the pawn but also takes the king
out of forking range. What happens next?
Imagine the board with White’s rook on f7
and Black’s king on g8, and you should see
that White then has an easy capture of a piece
with RxN: the rook has protection from the
knight on g5, and so cannot be recaptured by
Black’s king.
Dg018: White to move
Dg019: White to move
Dg018: The pattern repeats. White can fork
three Black pieces with Ne6+. The only difficulty is the pawn at f7 that guards the needed
square. There are various things one can do
about such problems. The most obvious is
simply to capture the pawn if you can, so here
it goes 1. Rxf7, RxR, and now the pawn has
been replaced by a piece that can't protect the
e6 square. True, White sacrificed a rook to the
cause; but now Ne6+ wins the queen. And
then after Black recaptures RxN, White picks
up a pawn that has been left loose by the sequence: Qxg6. White ends up trading a knight
and a rook for a queen and two pawns.
You might imagine that the g6 pawn could be
protected by Black's king, which (on this theory) would have escaped the knight fork by
moving to f6. But if Black does move his king
there, White mates in three moves. It starts
with Nc3-d5+. Black has no good replies; if
he plays BxNd5, for example, White has
Rf1+. This forces Black to play KxNe6. Now
White replies e4xBd5#.
Dg019: The usual color scan reveals a potential knight fork to be had at d6, but the square
is protected. How many times? Twice—by the
bishop at f8 and the knight at f7; be sure to
account for all the guards, not just the first
you notice. Fortunately White has bishops
attacking each of the two bothersome pieces,
but there still is a complication: when White’s
bishops take Black’s bishop and knight, Black
will use his king to recapture, and the king is
supposed to be one of the pieces in the fork.
Will its recaptures ruin the forking opportunity? Not necessarily; so long as the king ends
up on f7 it still can be forked. But this means
that it is important to perform the exchange
on f7 last so that the king ends its travels
there. Thus 1. BxB, KxB; 2. BxN, KxB; and
now Nd6 forks king and rook and so wins the
latter.
Naturally Black might prefer to bow out of
this sequence earlier, giving up a piece rather
than stepping into the fork. That's often how
tactics work, as we will see many times (but
won't always point out): the victim can escape
final execution of the fork or other idea, but
only by making a sacrifice. In that case—
which is normal—the tactic still must be
counted a success.
both out of commission. And it gets better
still: once Black's bishop on d5 is out of the
way, White's rook on d1 attacks the Black
rook on d8. So when White plays the fork, as
he now can, he can use his knight to take the
d8 rook without fear of recapture by the Black
rook on e7.
The point to take away from this example,
apart from the importance of accounting for
multiple defenders, is that the order of operations in a tactical sequence can matter a great
deal. Here the tactic doesn't work if White
takes Black’s knight first and his bishop second. When you consider a sequence that involves more than one exchange, ask whether
changes in the order of the moves would
make a difference to the outcome.
Dg021: Black to move
Dg020: White to move
Dg020: Black’s queen is about to take yours
for free. Your initial impulse might be to retreat your queen or play QxQ. Maybe one of
those moves is right, but don't play either until
you have asked whether they can be fit into an
offensive plan. White’s most advanced knight
is on a dark square; so are Black’s king and
one of his rooks, suggesting a fork at f7. Before you do anything you ask whether the
needed square is protected, and how many
times. Again, twice—by Black's bishop and
queen. Unless you can eliminate both defenders of f7, no fork. Each of the defenders is
attacked once: the Black bishop by your rook
at d1, and the Black queen by your queen.
The natural thought is to try QxQ, which you
were considering anyway for defensive purposes, and then to notice that Black’s recapture, BxQ, leaves the forking square f7 loose
for your knight. Capturing one of the two
guardians in the right order thus takes them
Dg021: By moving to e2 Black’s knight
would fork White’s king and queen. But the
needed square is under protection—twice,
from White’s knight and rook. Each of the
guardians is attacked only by Black’s queen.
So imagine taking out one of them, and then
imagine taking out the other. If QxN, then
White replies f2xQ (or BxQ) and the White
rook at e4 still guards the needed square. But
if Black begins with QxR, then White replies
NxQ and now e2 is available for Black’s
knight. Once more, an exchange of one of the
two guardians effectively gets rid of both of
them, as guardian #2 has to recapture the
piece that captured guardian #1.
2.1.5. Distracting the Guard.
In the positions we just considered, the guard
of the forking square always was under attack
by one of your pieces, making possible an
exchange that freed up the square for your
knight. But what if none of your pieces are
trained on the enemy pieces doing the guarding? Then capturing the guard won't work, but
there are other questions we can ask. Here's a
good one: is the guard also protecting some
other piece or square that you might attack,
thus distracting the guard away from its de-
fense of the forking square? This theme—
distracting the guard—is one we will consider
at many points in these materials; it gets a
chapter to itself toward the end.
Dg022: White to move
Dg022: In the example, the arrangement of
White’s e5 knight and the Black king and
queen naturally suggest a fork with Nf7. The
difficulty is that f7 is guarded by Black’s
rook. This time you can't capture the rook, so
ask if it protects anything else you can take. It
does: White plays QxN; if Black recaptures
RxQ, the f7 square is left loose and available
for White’s knight. The fork Nf7+ then wins
back the queen with the gain of a piece.
Dg023: Black has worries; he is up a piece
(though White has an extra pawn), but his
queen is pinned by White's rook and seems
about to be lost—and his knight on f4 is hanging (in other words, it is under attack and has
no protection). Look for counterplay before
falling into a defensive mindset. Black’s
knight and White’s king and queen are on
dark squares, suggesting a possible fork at e2.
Alas, e2 is protected by the knight at d4.
Dg023: Black to move
You look for ways to take out the knight directly but find none. So now look more
closely for anything else the knight protects
that you might take. It guards the rook at c6,
which you can capture with your queen—
extinguishing the pin as well. So 1…QxR; 2.
NxQ, Ne2+ and the fork is made. Black wins
the exchange, having traded queens and
swapped his knight for a rook.
Once you see the relationship between the
rook on c6 and the potential fork far away on
e2 (they are connected by the knight on d4,
which guards against both of them and thus is
overworked), you can choose between exploiting the situation at either end. In other
words, you can (a) play the sequence just described, or (b) start with Ne2+, allowing
White to play NxN, and then playing QxR
since the White rook’s guard (the knight) has
abandoned its defensive duties. Which sequence is better? Either way you end up
ahead the exchange, but the first sequence
also has the advantage of getting the queens
off the board—which magnifies the significance of Black’s material edge.
That last idea is worth another minute of explanation if it's not already familiar. In simplest terms, the point is this: if you have one
piece and your opponent has none, this lets
you dominate the game in a way that an edge
of five-to-four doesn't. So if you win a piece
from your opponent and have five pieces
against his four, your usual goal is to exchange away the rest of the pieces on the
board, making captures when you can; finally
you are left with the only attacker (at which
point your opponent probably resigns, if not
sooner). Naturally it follows that if you can
start whittling down the number of pieces on
the board while you're gaining your edge in
the first place, you want to do so—as Black
does here by starting with QxR.
Dg024: Black's knight is on a dark square.
White’s king and bishop also are on dark
squares, creating a potential fork at f3; but f3
is protected by the queen at d1. Can the queen
be captured?
Here as in the previous problem, the exchange
at the beginning both made the fork possible
and improved it by turning the guardian of the
forking square into a target. Notice that Black
really has no choice but to take White’s queen
with his king; if Black’s king merely moves
out of the way, White plays QxQ—a formation known as a skewer (you attack two pieces
on the same line; the more valuable gets out
of the way, leaving the less valuable to be
taken).
No. Is the queen protecting any other piece
that can be attacked? Yes, the bishop at d4—
and the bishop already is one of the pieces in
the fork. So if 1…QxB, 2. QxQ, you not only
have a clean fork at f3; you have a better one:
Nf3+ wins the queen.
There are other little trains of thought that
might have brought you to the solution here.
You could have just examined any checks you
are able to give and then realized that 1.
QxR+, KxQ leaves Black vulnerable to a
fork; or you might have seen that White can
attack the Black queen via Nxf7, and wondered whether there was a way to draw
Black’s king onto another dark square that
also could be attacked from f7.
Dg025: White to move
Dg026: White to move
Dg025: White’s queen is under attack. The
obvious impulse would be to move it to prevent RxQ, but that would be premature. First
take stock of your offensive possibilities.
Here you have a knight to work with; it's on a
dark square, and so are Black’s king, queen,
and rook—and the queen and rook can be
forked by Nxf7. But the needed square is
guarded by Black’s king. Ask whether the
king is protecting anything else White can
take, and see that it guards the Black rook. So:
1. QxR+ (extinguishing the threat with a temporary sacrifice), KxQ; 2. Nxf7+ and when
the smoke clears White will have gained a
rook.
Dg026: White’s knight is on a dark square, as
are Black’s king, queen, and both rooks; a
fork at g6 suggests itself. The square is protected—how many times? Twice: by the
queen and by the pawn at h7. The pawn is
pinned by White’s queen, so the problem is
just the defense of g6 by Black’s queen. Consider whether it is protecting any pieces that
you might take and you see that it guards the
rook at f8 and bishop at e5. You can’t capture
the bishop, but you can take the rook with
RxR. This looks a lot like the previous problem, but with a small difference: the rook at
f8 is protected twice—by the other rook at d8
as well as by the queen. If Black retakes with
his other rook instead of with his queen, you
Dg024: Black to move
still won’t have a fork. But then you will have
another rook at f1 that you can use to attack
again. Hence: 1. RxR+, RxR; 2. RxR+, QxR;
3. Nxg6+ and the fork is complete. Think of
this just as a case where two exchanges were
needed to lure away the guardian rather than
one.
Dg028: This is the same as the previous problem but a move earlier. It is given here as a
little study in how the same train of thought
looks from a defensive perspective. It would
be easy for White to imagine that he can afford to play a3xB since then Black's QxR is
met with QxQ. But when Black’s knight is
placed this dangerously it is unwise to initiate
any exchanges without making sure that no
forking opportunities will be created for it—
as would be here.
Dg027: Black to move
Dg027: It’s Black’s turn to play, and his
queen is attacked by the rook at a1 and the
pawn now on b4. It would be natural but erroneous for him to begin looking for places to
move the queen. Black has a well-advanced
knight at d4 and so should be looking for
forking chances. The knight can attack the
White king in one move to f3 or c2; and at c2
it can fork king and rook. The only trouble is
that the queen guards the needed square. Is
the queen protecting anything that Black can
attack? Yes—the rook at a1. So Black plays
1. ...QxR, which is met with 2. QxQ—now
making possible 2. ...Nxc2+. Black nets a
rook and a pawn. One lesson of the position is
that when you are under attack, sometimes the
best defense is a good offense: consider a capture rather than a retreat, and ask what the
board would look like afterwards.
Dg029: White to move
Dg029: White’s knight is on a light square.
You see a potential fork at e7, but the square
is protected by the rook at e6. Can that rook
be exchanged away? No, White has nothing
attacking it. So is the rook protecting anything
else that can be taken? The main thing it is
protecting is the other rook at c6; so if that
rook could be taken, the rook at e6 would
have to move over to recapture, and then the
fork at e7 would work. Here as in the previous example, White has a battery of rooks
aimed at the critical Black rook on c6. If only
the pawn at c5 weren’t in the way. Might it be
removed, or simply moved? What is it protecting? The pawn at d4, which is protected
twice. So if 1. Bxd4, BxB+; then 2. Rc4xB,
c5xR—and finally 3. Rc1xR, RxR. Now at
last the fork can be achieved with Ne7+.
Structurally this example is easy enough to
understand: the rook on e6 has to be attracted
away to c6 for the fork to work; but before c6
can be attacked, two preliminary exchanges
are needed to clear the way. What makes it
tricky is that each of those initial exchanges
involves choices by both sides about which
pieces to use—including pieces that you
Dg028: White to move
might barely have noticed on initial inspection of the position. For example, if you’re
not mindful of all of the pieces on the board it
is easy to overlook Black’s bishop on g7 and
to imagine that if White plays Bxd4, Black
will have to recapture with his c5 pawn.
Likewise, if you’re not careful it is possible to
overlook White’s second rook on the c-file,
and thus fail to see that with the rook on c4
and pawn on c5 out of the way, White will
have a clear shot at Black’s rook on c6. The
general lesson is not to let any of the pieces
on the board drift off your radar screen, and
always to ask whether there is more than one
way for you or your opponent to capture or
recapture in a series of exchanges.
This position is a good example of how to
work backwards from a tactical idea to several exchanges needed to make it work. It is
worth considering until the train of thought is
clear.
Dg030: White to move
move Nxd5. To see its full significance we
need to consider Black’s king and the constraints on its movement. White can give
check with Qh8. This would be mate except
that Black’s king has a flight square in e7.
The e7 square itself thus is a vulnerability, or
target, in Black’s position; and now return to
White’s Nxd5 and see that it forks the e7
square and Black’s queen. So Black has to
reply BxN to avoid mate, which in turn allows
White’s next fork: Nd7+.
Indeed, White can turn these insights around
and play an even stronger sequence by starting with Nd7+. If Black then plays BxN,
White replies Nxd5 and Black has headaches:
he is required to take emergency steps to prevent White from mating on h8, and finds that
he has no way to capture White’s troublesome
knight. He has to play g7-g6 so that his own
queen has an open line to guard h8 if White’s
queen lands there. But now White has NxQ,
and (assuming Black moves his king to e7)
NxR. Black is better off replying to the initial
Nd7+ by moving his king to e7 and letting his
queen be traded away for a knight. All this
suits White, who still ends up winning Black's
queen but at lower cost than in our original
plan.
How would you see these richer ideas in the
position? It all starts by focusing on the enemy king, how you threaten it, and how your
threats are being staved off. We will see many
times how this approach to analysis pays off
with useful tactical ideas.
Dg030: The usual scan of knight moves reveals that White’s most advanced knight has a
fork at d7, but d7 is guarded by the Black
bishop at e6. The bishop can’t be captured;
you have no piece trained on it. But the
bishop also guards the pawn at d5—which
can be taken by your other knight at c3. So
Nxd5, and you gain a pawn. If Black recaptures with BxN, you have Nd7+; after you
next play NxQ and Black recaptures, you've
won a queen and a pawn for two knights.
That's a simple analysis of the position along
the lines we have been discussing. But there
also is another, better way to size it up. Let’s
look a little more deeply at White’s initial
Dg031: White to move
Dg031: White has several pieces bearing
down on the Black king’s general position—a
queen trained on h7, a rook on the sixth rank,
another rook on the f-file, and a knight nearby
as well. Focus on that last piece: when you
have a knight near the enemy king, the search
for forks should be automatic; all those other
pieces nearby are important in part because
they can be used as tools to help make a fork
work. In this case you see that White’s knight
has a forking square in f6. The trouble is that
the needed square is protected by the pawn on
g7. White has no way to take the pawn, and it
doesn’t protect any pieces White can take,
either. But it does protect sensitive squares
near Black’s king, so putting an attacker on
one of those squares may be as good as taking
a piece the pawn protects. Here White sees
that since his queen already attacks h7, adding
another attacker against that square would
create a mate threat. (This is a common formula: if your queen attacks a square adjacent
to the enemy king, adding another attacker
against the same square often creates a threat
of mate.) Thus White plays Rh6. The rook
now provides the cover White needs to play
Qxh7# next move. To prevent this Black has
to play g7xR—and now the f6 square is available for White’s knight. He plays Nf6+, and
after NxQ next move White has won a queen
for a rook.
We see again the power of combining our
knowledge of the knight fork with a close
look at your mating threats against the enemy
king.
Dg032: White to move
Dg032: Here is another application of the
same idea: thinking about whether you can
distract a guard by making a threat from a
square it protects. Here White’s knight is on a
dark square. So are Black’s king and queen,
and they can be forked at e6. The trouble is
that the square is protected by the Black
bishop on f7. The bishop can't be captured;
none of White’s pieces attacks it. Nor is the
bishop quite protecting any pieces that White
can take. It guards the d5 pawn, but so does
the c6 pawn. But now you also can ask
whether the restricted bishop is protecting any
squares that White can occupy. Mostly you
want to see if it is guarding any squares next
to Black’s king, because then you may be able
to draw it away by threatening mate on one of
those squares. Think of it this way: the bishop
on f7 is confined (if it wants to prevent the
fork Ne6) to the diagonal running from a2-g8;
it really cannot afford to go off on the e8-h5
diagonal—so look for play there.
What you find is that if White’s rook moves
forward a square to h5, it checks the Black
king. The king wouldn’t be able to capture it
because the square also is attacked by a
knight, so Black would have to respond to the
check in some other way. Let's consider the
possibilities:
One option would be for him to take the rook
with his bishop, which would clear the way
for the fork White seeks. The idea is 1. Rh5+,
BxR; 2. Ne6+, Kf6; 3. NxQ. This looks
strong, and it is—but take a moment to ask
how Black will reply at the end. He has Rc8,
attacking the knight; and this turns out to be
surprisingly troublesome, since the knight has
nowhere safe to go. Na6 is met with Ra8, renewing the attack and the knight still has no
retreat. But the knight can take a pawn on the
way down by replying to Rc8 with Nxd5; and
then after Black recaptures (c6xNd5), White
grabs yet another Black pawn, and creates a
passed pawn of his own, with Bxb5. So in the
end White ends up winning a queen and two
pawns for a knight and a rook.
Another possibility is that Black could reply
to Rh5 by moving his king to f6. So look for
your next check and find Rxf5. When the king
moves again in response, you ask whether any
Black pieces will have been loosened―i.e.,
left unprotected―by all this activity, and you
find KxN for White.
This problem is a good example of a valuable
general point: effective combinations often
require both (a) pattern recognition, and (b)
skill at identifying forcing moves—especially
checks—and their consequences. The key
move here—Rh5+—might have been spotted
in an effort to make the fork work, or it might
as well have been spotted just by examining
the consequences of any checks you can give
and any vulnerabilities of the enemy king.
You notice that one of the possible Black responses to this particular check would be
BxR; you imagine the board with your rook
and his bishop moved, and a simple color
scan or inspection of knight moves reveals the
fork waiting at e6. If Black instead responds
to the check with Kf6, you look for the next
check, and so forth.
Dg033: Black to move
Dg033: Here is another more complicated
sequence; it will take a bit of patience to untangle. Black’s knight is on a dark square in
White’s territory; also on dark squares are all
of White’s most valuable pieces—king,
queen, and both rooks. Start by just looking at
each of the knight’s moves in search of potential forks. There are two: Ne2+, forking
White’s king, queen, and rook; and Nd3, attacking both rooks. Now carefully identify
what prevents either of those two moves.
Ne2+ is stopped by one thing: the rook at e1
that protects the square. Nd3 is stopped by
two things: The knight at f2 and queen at g3
that both protect the square. Take stock next
of what resources Black can bring to bear
against those guardians. White’s queen can be
taken by Black’s queen. As for the knight at
f2 and the rook at e1, neither of them can be
captured by Black. So next consider whether
they are guarding anything Black can attack,
and they are: they both protect the knight at
e4. Can Black attack that knight? Yes, twice:
with the bishop at f5 and the queen behind it.
Now begin thinking about possible move orders and their consequences, always bearing
in mind that you are hoping to free up either
d3 or e2 for your knight. Try BxN. How will
White respond? There are two possibilities if
he chooses to recapture: NxB or RxB. If NxB,
then one of the two guardians of d3 has been
eliminated; only the queen remains, and it can
then be taken with QxQ. After White then
plays h2xQ, Black can play Nd3, forking the
rooks. If White instead plays RxB, the rook
still guards e2. But Black can attack it again;
remember that when two pieces are lined up
like the queen and bishop here, they attack e4
twice. So Black plays QxR, and after White
replies with NxQ the e2 square is available
for Ne2+, forking White’s king and queen.
The conclusion: Black wins by starting with
BxN, because any recapture White makes in
response leads to a knight fork for Black.
This position is tricky because Black has two
offensive options and White has choices to
make as well in response to BxN. But a methodical examination of Black’s goals, the
impediments to them, and White’s possible
replies to Black’s captures nevertheless
breaks it all down easily enough.
Dg034: White to move
Dg034: Black’s knight on d4 is creating a
great deal of trouble; it's about to take White’s
queen and also threatens a fork at e2. The
natural idea is to take the knight—but with
your bishop or with your own knight? Con-
sider what else you can do with either of
them. White’s knight is on a light square, and
so are Black’s queen and rook (and his king,
but for now only the queen and rook are
within range of White’s knight). White would
like to play the fork Nxe5, but now he can’t.
The problem isn’t the pawn on e5; it’s the
pawn on f6 that guards e5. White has no other
pieces he can use to capture either pawn, but
the more natural way to get rid of troublesome pawns is to capture things they protect,
for then they move to recapture and no longer
guard the squares they once did. So White
breaks the logjam with BxN, forcing Black to
recapture with e5xB. Now the path is clear for
White to play e4-e5, still in an effort to get the
f6 pawn to move. Black has to play f6xe5 (if
he instead moves his knight away from d6,
White pushes the pawn to e6 and forks the
rook and queen with cover from his own
queen at b3). At last nothing guards e5, so
White can play Nxe5, forking queen and rook
and winning the exchange.
Observe how the whole sequence was driven
by an idea: if the f6 pawn could be lured off
of guard duty of e5, the fork would be possible; so White works on ways to attract it away
with captures and threats.
protect something else, creating a way to
break the jam? If White somehow could force
a Black piece onto d4, then he could take it
with his bishop, initiating the sequence described a moment ago. So he experiments
with threats; a2-a4 forces the knight to move,
and to where? A knight has a maximum of
eight places it can move when attacked, and
when it’s near the side of the board the number is smaller. Here there are just six squares
it can reach, and only one that is available and
doesn’t result in immediate capture: Black
plays Nd4. And now the stage is set for the
sequence examined in the previous problem.
None of this is easy to see. And if you did see
it, it might have been as a result not of spotting the forking idea but just of playing with
threats and their consequences. You start
thinking about a2-a4, see where the knight
goes, imagine taking it once it lands on d4,
see that this clears the way for a pawn push to
e5, observe that Black needs to take the pawn,
and then at last come up with the knight fork
on e5 at the end. But it's a lot easier to think
usefully about these things if you know that
you have a potential knight fork lurking on e5
if conditions change. That threat lends structure to the train of thought about your forcing
moves and where they lead.
Anyway, look at this position also as another
study in the art of getting a bothersome pawn
out of your way. If you can force an enemy
piece to become a protectorate of the pawn,
you can then capture the piece and force the
pawn to recapture, moving out of the way.
2.1.6. Getting Out of Your Own Way.
Dg035: White to move
Dg035: Here is the same position still one
move earlier. The train of thought starts the
same, but here there is no way to get the e5
pawn off of its square by attacking something
it protects; for it protects nothing. Observe the
difficulty of forcing an enemy pawn to move
when it protects nothing that you can capture.
Don’t give up, though: can you play a forcing
move that will cause one of the pawns to then
You don't want to overlook a potential fork
just because the forking square already is occupied by one of your own pieces. Ask: can
the piece that is in the way evacuate the
square violently, thus requiring a timeconsuming response from your opponent and
making the fork possible on your next move?
Dg036: In this first example White’s knight is
on a light square and so are Black’s king and
rook.
smashing finale if your opponent recaptures
after each of them; but of course he may not
recapture, leaving you with lesser gains. In a
good game of chess this often is the importance of seeing tactics. You may or may not
actually get to play the fork, but seeing the
threat of it allows you to make other gains.
Dg036: White to move
Or just look at the knight’s potential moves
without being distracted by pieces of your
own that already occupy the squares the
knight might like to reach. Either way the
point to notice is the potential fork at f6. The
trouble is that White’s own rook already is on
the square. There is standard method for dealing with this: Ask whether the rook can be
moved in a way that requires an immediate
reply from Black, keeping his king and rook
where they are. A capture is good for the purpose, and the one possible here is RxN: it
calls for Black to respond b7xR, and White
then follows up with Nf6+.
Keep track of what you are losing and gaining. Here you have sacrificed a rook for a
knight, and are about to win a rook. But then
won't you lose your knight after the fork,
leaving the sequence a wash? No, though that
would be true if Black could respond to the
fork with Kf8, for then after NxR Black could
play KxN. But here Black can’t play Kf8 because White has a pawn guarding the square.
Black has to play Kh8, and then White wins
the rook cleanly.
When we say that White's initial RxN "requires" or "calls for" Black to play b7xR, this
should not be taken literally. If Black sees this
sequence coming he will respond to RxN by
forgetting about his lost knight and instead
moving his king to avoid the fork at f6. This
is a point common to many of our studies:
you have a series of captures that lead to a
Dg037: White to move
Dg037: White’s knight is on a dark square; so
are Black’s queen and rook. Thus there is a
forking square at f3 which is easy to overlook
but should be made no less visible to you by
the presence on it of White’s own queen. You
need a move for the queen that forces a response from Black, making Nf3 possible. You
might first see QxN, but look harder for a
check or capture that doesn’t require you to
sacrifice the queen. Correct is 1. Qa8+. 1. …
Kh7 then is forced (Ne8 just loses the knight);
and 2. Nf3 can then follow. White wins the
exchange.
Most of our forks so far have involved the
enemy king as one of the targets, but not this
one. When the enemy king is not a party to a
fork you are considering, it is important to
pause and ask whether either of the forked
pieces would be able to break out of it and do
damage or seize the initiative with a check. In
this case that’s not a problem, though; neither
Black’s queen nor his rook has a good option.
Dg038: A color scan or a look at the White
knight's circle of moves turns up a potential
fork to be had at e6, and again its potential
should not be obscured by the presence of
White’s queen there. The question is whether
the queen can make a move that will force
Black’s response, giving him no time to prevent the fork Ne6+ a move later.
Dg038: White to move
First you look for a check, but it turns out that
most of the squares from which the queen can
attack the king―e7, e8, f6, f7, g8, d6—result
either in (a) the queen being captured by
Black’s king or queen, which ruins the fork,
or (b) the king simply moving, which likewise
ruins the fork. But if you persist you come up
with 1. QxR+. If 1. …RxQ, then 2. Ne6+,
forking king and queen; and if not RxQ, so
much the better: after 1. ...Ke7, White can
play QxRc7+ and has still more fun from
there.
check. There is just one: QxN. What follows
from that? Either g6xQ or RxQ; and either
way, Ne6+ picks up Black’s queen and wins a
knight with the sequence.
Incidentally, it may come as a small surprise
to you to hear that White's rook on c1 is doing
absolutely essential work in this position. Do
you see why? It protects f1. If the rook on c1
were gone and f1 thus were unprotected,
Black would reply to QxN with RxQ, aiming
his rook at White’s back rank—and then after
White finishes his knight fork with NxQ,
Black has Rf1#, checkmating White’s trapped
king. The moral: be ever mindful of your own
king’s vulnerabilities and how any offensive
sequences you are planning may unexpectedly
expose it to checks (and worse) that are not
possible on the board in front of you.
Dg040: White to move
Dg039: White to move
Dg039: White’s knight is on a dark square. So
are Black’s king, queen, and rook. Ne6+
would be great, but White’s queen is in the
way. The question, now familiar, is whether
the queen can make a move that will force a
response from Black that costs him a move.
You might start by examining, if briefly, any
checks the queen can administer, but all of
them cause either Black’s king or queen to
move, ruining the fork. So now look for captures the queen can make without giving
Dg040: This example combines two recent
points we have studied. The initial key is to
see the potential knight fork Nd5 despite the
fact that you already occupy d5 with another
piece. The question is how best to vacate the
bishop from the forking square. It runs on the
light squares and the king is on a dark one, so
the bishop won’t be able to deliver a check. Is
there anything that it might capture? Yes:
Black’s bishop. But before you play BxB,
notice (as would be obvious in a game) that
Black is about to play QxQ, ruining your fun.
So the correct play goes 1. QxQ, RxQ; then 2.
BxB, b5xB; 3. Nd5, forking the rooks.
This position, like the previous one, contains
a rook that looks unassuming but that provides crucial support for the whole sequence:
the one on f1. Imagine it gone and rethink the
position. Now in reply to 3. Nd5, Black
moves his rook from e7 to d7; and if White
then plays the capture NxRf6, Black has
RxRd1+. (In effect Black uses his rook to pin
the White knight to the White rook on d1.) In
the actual position White’s rook on f1 prevents this because it protects the rook on d1.
The general lesson you can draw from this
little note is that loose pieces (as the d1 rook
would be if the f1 rook were gone) are a hazard. Even if they don’t appear to be part of the
action, they can find themselves suddenly
captured during or after a sequence you are
planning elsewhere.
2.1.7. Unsuitable Targets.
Sometimes a knight fork is available but only
one of the forkable pieces is a good target; the
other is a piece of equal or lesser value to
your knight, and perhaps is guarded. The
question then is whether the bad target can be
made a good one through an exchange.
Dg042: White to move
Dg042: White’s knight is on a dark square.
Black’s queen and knight are on dark squares
(and also the king, but at the moment it’s too
far away to fork). So you need to see that
White has a potential fork at e4 but that one
of the targets is Black’s knight, which won't
do. Ask whether White can take the knight
with something else and thus cause it to be
exchanged for a suitable target. He can, by
playing QxN+; if Black responds KxQ, White
has Ne4+, forking king and queen. He ends
up gaining a knight. Throwing away your
queen to take an enemy knight looks counterintuitive, but a temporary sacrifice of this
kind is a common opening thrust in a tactical
sequence.
Dg041: Black to move
Dg041: We start here with a case where at
first glance there might seem to be no forking
possibility for Black. The point to see is that
Nc5 is a potential knight fork even though it
won't work now because one of its targets is
another knight (so Black's Nc5+ is simply met
with NxN). Ask whether you can make your
opponent replace the knight with something
better by forcing an exchange. Here Black
gets it done by taking the knight with his
rook: 1. …RxN, BxR, and now Nc5+ wins the
bishop and thus gains two pieces for the rook.
Dg044: White to move
Dg044: White’s knight is on a light square;
Black’s king and knight also are on light
squares and can be forked at e7. If you notice
the forking idea at all here—in other words, if
you aren't lulled into overlooking it because
the target on c6 is another knight—you are
most of the way home. Of course the knight is
an unsuitable target, so you force Black to
replace it by first taking it with another piece.
Thus 1. QxN; QxQ; 2. NxB+. After playing
out the fork White has won two pieces.
knight can be taken by any of White’s pieces,
and see that one of them—the rook—is ready
to do the job, and with check. After RxN+
Black appears to have a choice of recapturing
with his queen or king, but on closer inspection the queen is pinned. So the only recapture
is KxR; and then Nc5+ follows. And again the
same result can be reached by just experimenting from the outset with the check
RxN+. After the recapture KxR you see
Black's king and queen in the telltale position
for a knight fork.
Dg045: Black to move
Dg045: Nxd4 looks implausible for Black because
it loses a knight for a pawn. But the implications
of the move change when you see that it is a fork,
attacking the knight on e2 and the queen at f5. For
then you see the real question is whether White's
knight can be replaced with a working target. It
can: Black plays 1. … QxN+; 2. KxQ, Nxd4+,
winning back the queen with the net gain of a
pawn after White recaptures RxN. Like many of
these positions, this one can be solved as well by
having a look at the consequences of any checks
you can give. Black’s queen can deliver check in
four ways; one of them, QxN, moves the king into
a new position in which the fork might be seen if
it wasn’t already.
Dg046: White to move
Dg046: White’s knight is on a light square, as
are Black’s queen and knight. The structure
of a fork is there; if the Black knight could be
replaced with the king, the fork would become playable with Nc5. So ask whether the
Dg047: White to move
Dg047: White’s knight is on a dark square,
along with Black’s knight and king. There is a
potential fork at f5, but the g3 knight is
pinned, f5 is protected by both queen and
knight, and anyway the fork is of no use because it ends up trading a knight for a knight.
So it’s only the barest glimmer of an idea, but
when you ask whether you can capture the d4
knight with something else (and what happens
then) you find 1. QxN+, QxQ; 2. Nf5+, a
knight fork that wins a piece.
Regardless of whether the fork occurred to
you at the start, consideration of QxN+ would
have been mandatory because it was one of
White’s three possible checks. We keep emphasizing these separate paths to the solution—i.e., showing how it might have been
found by looking at checks and their consequences—because in many positions the idea
isn't as clear at the outset as it perhaps has
been in these early positions; and in that case
starting with a look at your forcing moves is
the best way to find tactical ideas. In this case,
after imagining QxN+ and the recapture QxQ
you reevaluate your knight's tactical prospects. You notice that your knight and
Black’s queen and king all would be sitting
on dark squares (and the knight would have
become unpinned), calling for the fork Nf5+.
Dg048: White to move
White’s knight is on a dark square; so are
Black’s bishop and rook. You see a knight
fork at c6. But it won’t work because Black
can respond by moving his rook to e8, both
taking it out of harm’s way and using it to
protect the bishop. As we know, this is a
common difficulty when forking two pieces
neither of which are the king; one often can
move to protect the other. Can you improve
the target by capturing one of the pieces and
forcing an exchange? Yes, with RxB+, to
which Black replies KxR. Then comes Nc6+,
and now White wins the rook; moving the
rook to protect the other piece doesn’t work
anymore for Black because now the other
piece is a king.
Dg049: White to move
Dg049: White’s knight is on a dark square.
Both of Black’s rooks and his bishop likewise
are on dark squares and are positioned for a
fork at d7. Black’s queen guards the square
but can be eliminated with the simple capture
1. QxQ. Consider Black’s possible replies to
that move. RxQ is out because the rook is
pinned. It will have to be 1. …KxQ or 1
…BxQ, either of which leaves d7 available
for White’s knight. Yet this is no good because then Nd7 is met by Black with RxR!
Again, when you are forking pieces and none
of them are a king, you need to ask what
damage any of them might be able to do while
breaking out of the fork. And anyway you
should not be settling for a fork of a bishop
and rook when the king is so close to being on
a forking square as well. So after the exchange of queens White plays 2. RxR+,
KxR―then Nd7+, winning a rook with the
sequence.
Dg050: White to move
Dg050: Now combine the current theme with
an earlier one. A routine color scan (or a look
at your checks, or a look at your knight
moves) turns up a potential fork of Black’s
king (good) and knight (no good) to be had by
playing Nxc6. Can the knight on b4 be exchanged for something better? And what
about the fact that the forking square, c6, is
guarded? Experiment with exchanges that
may clarify the board. 1. Ra4xN leads to 1.
…RxR; now the fork has a better target in the
rook, but the forking square still is protected
by the second Black rook at b6. So it becomes
a straightforward problem of attracting away
the guardian of the forking square by attacking a piece it protects. Just do another exchange: 2. RxR, RxR then allows Nxc6+.
keeps the opponent too busy to do anything
about the forthcoming fork. In this case the
initial move Nf8 threatens Black's queen, so
his choice of replies is very limited.
2.1.8. Playing Defective Knight Forks.
Dg051: White to move
Dg051: This one takes a little imagination.
You might start by seeing the capture you
have available: QxN. It doesn’t work because
Black’s knight is guarded by its queen. Might
you be able to chase away the queen, as with
Nc5 or Nf8? No, because the queen just
moves to another square from which it guards
the knight (e.g., Qe8 or Qd6). But when your
own knight is nearby the thought of a fork
always is there, and now such a possibility
comes into view: notice the position of
Black’s king and knight; they are on squares
that are poised to be forked. If Black’s queen
were substituted for his knight, White’s
knight could fork them if it could get to g6.
White’s knight can’t get to g6 from its current
perch, but in two steps it becomes possible.
First comes Nf8, attacking Black's queen. The
queen moves anyplace where it still can protect the knight; White plays the exchange 2.
QxN, QxQ; and now 3. Nxg6+ imposes the
fork, wins back the queen, and gains White a
piece.
Another way to think here, I suppose―the
reader can judge its utility―is to say it's a
case where the knight isn't on the right colored square at the start, so it needs to make
two moves rather than one: first a move to a
dark colored square, to match the one where
the king sits; then, after the queen is likewise
moved to a dark square, the fork from g6. But
notice that this pattern―two knight
moves―is likely to work only when the
knight makes a threat on its first move which
Suppose you spot a potential fork but find that
the forking square is defended and there is no
way to pin the defender, capture it, or capture
anything it protects. It still isn’t time to give
up; instead, imagine going ahead with the
fork and letting your knight be captured. Picture the board as it then will look: without
your knight, and with your opponent’s guard
moved from its current square onto the forking square. What then would be possible?
Consider the consequences of any checks you
then would be able to inflict; consider
whether the stage has been set for another
fork; consider whether any pieces that used to
be protected now are loose; consider whether
any open lines have been created that would
allow you to pin one piece to another. Indeed,
sometimes playing fork and letting it fail is
more powerful than "perfecting" it by removing the guard of the forking square. And
sometimes you thus will find that an implausible-looking fork works after all because the
cost to your opponent of taking your knight is
too high. All this will be made clear with
some examples.
In the position to the left White has the makings of a fork with Ne7+, but e7 is protected
by the Black queen. The queen cannot be captured or threatened, and White can’t attack
anything else the queen protects. So: what if
White goes ahead with the fork and Black
plays QxN?
Dg052: What will the board then look like?
Two things will have changed: the White
knight will be off the board and the Black
queen will have moved from e6 to e7. Both
changes are significant. The removal of the
knight creates an open line on the c-file, allowing the White queen to attack the rook at
c8; and the movement of the Black queen
removes the rook’s protection, leaving it
loose.
You might as easily have seen the idea the
other way around: you observe that your battery of rooks on the g-file nearly is ready to
mate on g8, but that the bishop on g7 stands
in your way; this means the bishop is pinned
(we will see many studies like this in the
chapters on pins), and is not really defending
e5. Since the e5 pawn’s other defender also is
pinned (to its queen), e5 is available to your
knight for a possible fork.
Dg052: White to move
So White then plays QxR+ and takes a rook
for a knight, winning the exchange.
In any event, if Black sees all this as well as
you do (and you should assume he will), the
actual consequences of the forking move
Nxe5 still require some thought. If he tries to
forfeit “only” the exchange by just moving his
queen and letting go of the rook on f7, Black
ends up losing more than that; for White can
instead take the rook on c4 at no cost. Notice
that once White plays Nxe5, the c4 rook is
attacked twice by White and protected only
once by Black. So the lesser evil for Black in
reply to 1. Nxe5 probably is 1. … d6xN; 2.
RxQ, RxRc6 losing his queen and a pawn in
return for a knight and a rook.
Dg053: White to move
Dg053: Both White knights are on light
squares. So are Black’s queen and both of his
rooks. The knight on d5 has no forking
moves, but the knight on d3 has one: Nxe5,
forking the queen and both rooks. Is the
square protected? Yes―twice (all defenders
must be accounted for!). Start by worrying
about the pawn on d6. It turns out to be a nonissue because it is pinned to its queen by
White’s rook at g6. That leaves the bishop on
g7 to consider. Imagine the board after 1.
Nxe5, BxN. What lines would that exchange
open, and what checks would you then have?
Just one: Rg8. Examine its consequences and
you find that they can be summarized in a
word: mate! For when you imagine the king
fleeing to e7, notice that your d5 knight already attacks the square; and you should be
mindful from the beginning of the battery of
rooks you have bearing down on the g-file
adjacent to the king.
Dg054: White to move
Dg054: White’s knight is on the same color
square as Black’s king and queen and can
fork them at f7. Black protects the square with
his rook. If White tries to start by taking out
the rook with his queen, Black recaptures
with his own queen and the fork is spoiled. If
White plays QxQ, however, Black replies
with RxQ, and now the fork works, winning
White a rook. Yet with king and queen positioned like this it would be rash to settle for a
rook; consider what happens if White simply
goes ahead with 1. Nxf7+ and allows his
knight to be captured by RxN. Now Black's
queen is left loose for the taking with QxQ,
which mates a move later (after Black gives a
futile interposition with his rook). So the fork
1. Nxf7+ works after all, as the lesser evil for
Black is letting his queen be taken by White’s
knight—after which Black recaptures with his
rook, allowing White to then play QxR+.
White ends up with a queen and a rook
against Black’s two knights, an easy win from
here.
Dg056: White to move
Dg055: White to move
Dg055: 1. Ng6+ looks like a promising fork
of Black's king and rook, impeded only by the
knight at e7. One way to handle this, of
course, is to capture the knight with 1. RxN,
to which Black replies 1. …BxR. Now the
fork Ng6+ wins back the exchange, but the
sequence is a wash. So start again, taking a
moment to look at what happens if you try for
the fork without clearing g6 and just let the
knight get taken. Notice especially the battery
of two rooks on the seventh rank, which is
always a powerful combination. If Black replies to Ng6 with NxN, that opens the seventh
rank; what checks does White then have? Answer: just one; RxR―which is mate. So
Black doesn’t dare play 1. ...NxN; in effect
his knight is pinned to the mating square at
h7. White’s best bet thus is to play 1. Ng6+
straightaway followed by NxN, as this wins a
whole knight for free—a rare case where a
knight fork wins a knight. If White instead
finishes with NxR, he merely wins the exchange, as Black will then be in a position to
recapture with his king (it would have moved
to g7) whereas if White finishes with NxN
Black can't recapture with his rook because
his king is in the way.
Dg056: White’s knight and Black’s queen and
rook are on dark squares; White would like to
play Nh7 to fork them, but then Black’s king
can capture the knight. So what then? Consider the position that results. When the king
or the pieces around it move, it’s always wise
to begin by checking for any pieces that may
have become pinned—pieces, in other words,
that now find themselves lined up with the
king and that can’t move without exposing it
to attack. Here the king’s move to h7 would
cause the pawn on g6 to become pinned. As
we know from earlier studies, a key consequence of a pin is that the pinned piece can't
guard anything because it can't move. In this
case the pin of the g6 pawn means the h5
pawn—and perhaps more importantly the h5
square—are left loose. Perhaps you can take
advantage. Carefully examine any check that
could be given from there. Think of Qxh5+.
The king would have to retreat to g7 or g8.
With the rook behind it, the queen then can
move in for the kill: Qh7#.
So the original knight fork Nh7 does work,
winning the exchange; Black can't afford to
play KxN, and so must move his queen and
let his rook be taken. But it only becomes
possible to see this once you imagine what
would happen if the fork "failed" because
your knight got taken.
Dg057: White’s more advanced knight has no
potential forks except the ineffective Ne6.
The less advanced knight at e4, however, is
on the same color square as Black’s king and
queen, suggesting a fork at f6. The needed
square is protected by Black’s bishop at g7,
and on inspection you see that the bishop
cannot be pinned, captured, or lured away by
an attack on one of its protectorates.
Dg057: White to move
But imagine proceeding with the fork anyway
and allowing BxN; in other words, picture the
board with the knight on e4 gone and the
Black bishop moved to f6. You are especially
interested in whether that sacrifice might
make an attack on Black’s king possible, so
study its position carefully. Consider any pins
that would be in place and any lines that
would have been opened by that little exchange. Starting with pins, White’s bishop at
c4 already pins Black’s pawn at f7, and still
will do so after 1. Nf6+, BxN. As for open
lines, the move of the e4 knight would have
opened a path for your queen to g6, where it
would be possible for you to give a new check
(g6 is loose; this is the significance of the pin
we just noted).
In reply to 2. Qxg6+, Black would be able to
play Bg7 or move his king to h8; either way
mate follows with Qh7, since h7 is guarded
by White’s remaining knight. So the original
fork at f6 wins at least the queen for a knight,
and delivers mate if Black is careless.
Dg058: White to move
Dg058: White’s knight is on a light square,
along with Black’s king and queen. Examine
every square the knight can move to and a
fork at d8 suggests itself; but d8 is protected
by one of Black’s rooks. You look for ways to
pin, capture, or distract the rook, and find
none. But before giving up on the thought,
imagine carrying out the fork and letting the
knight get taken; ask how the board would
look with the knight gone and the rook moved
to d8. Methodically imagine any checks you
then would have. The most interesting is
Qxe7, since it's safe and attacks not only
Black's king but also the now-loose rook on
d8. How would Black respond to the latter
threat? With Kg8; it would be his only legal
move. Now White has the simple QxR+. Here
the fork is just a means to an end, viz., capturing the rook and winning the exchange.
Dg059: White to move
Dg059: White’s knight is on a light square, as
are Black’s king, queen, and rook. You try
first to fork the two more valuable pieces and
so see that Nxf6+ attacks the king and queen.
The trouble is that g7xN follows. Black’s gpawn can’t be pinned, captured, or distracted.
But you must habitually persevere, playing
the moves in your mind’s eye and imagining
the aftermath and its opportunities: think of
the board without White’s knight and (in effect) without Black’s g-pawn, which will have
replaced his current f-pawn. Examine every
check you then would have—with every
piece. There would be three: Qf5; Qxd4; and
Rxd4. The first, Qf5, is met with QxQ and
nothing more. The second, Qxd4, causes
Black to play QxQ and then White to play
RxQ+; the king moves, and in the end White
has traded his knight for two pawns. But
Rxd4+ is another matter. If Black moves his
king, White plays RxQ. If Black plays QxR,
White plays QxQ. So the original move,
Nxf6, is a good one, gaining Black’s queen
and two pawns in return for a knight and a
rook.
Dg061: Black to move
Dg060: White to move
Dg060: White’s more advanced knight at f5
has no good forks; the only Black pieces on
the knight's square color are the king and
bishop, which can’t be reached from any
square within range. White’s other knight,
though, is on a dark square (d4), and so are
Black’s queen and one of his rooks. So how
about Nxc6? The square is protected by
Black’s bishop, which can’t be pinned, captured, or distracted. But still: if White plays
Nxc6 and Black replies with BxN, what then
is possible? Imagine White’s d4 knight off the
board and Black’s bishop at c6, and then examine every check. There are two: Nxh6+,
which doesn't help, and Ne7+—which forks
the king and bishop. Then it gets even better:
Black has no alternative but to move his king;
White then plays Nxc6, winning the bishop
and inflicting yet another fork, this time of
Black’s queen and rook. Now it's safe because
the bishop is gone.
A lesson of the position: anytime a sequence
calls for a knight to move in enemy territory,
think about whether its move might be a (or
another) fork. Remember that every move by
a knight changes the color of the square on
which it sits, and thus may radically change
its forking prospects.
Dg061: Black’s advanced knight at c3 is on a
dark square. So are White’s king, queen,
bishop, and rook; examine the knight’s ring of
possible moves, and see that the king and
queen can be forked at e4—but that the
square is protected by the pawn at f3. Can the
pawn be pinned, captured, or distracted? No,
no, and no. Okay; what results if Black plays
the fork anyway and permits f3xN? Visualize
what is left on the board. Black then has two
checks—Qd2 and Qe1—but neither are helpful since White captures the queen in either
case. Nor does Black have any further knight
forks. But remember that when considering an
exchange you also want to examine what lines
would be opened by it and what pins then
would exist or become possible. Here, moving White’s f-pawn to e4 would put White's
king and queen on the same file with nothing
between them. Anytime you see this pattern
you should be thinking “pin”; the opponent’s
second piece will be powerless to move when
attacked if moving would expose the king.
(Consider this a preview of the patterns we
will be studying in our later work on pins.)
Here Black would be able to pin the queen
with Rf8 and take it a move later. So the
original Ne4+ ends up winning the queen after all in exchange for the knight and a rook.
If you didn’t spot this, it’s probably because
you haven’t studied the art of the pin in any
detail—a problem we will cure later. But the
next couple of positions also will offer some
practice in thinking about pins that may arise
after a "failed" fork. Watch for them.
Dg062: White’s knight is on a light square, as
are Black’s king and queen, calling for con-
sideration of a fork at b6. Black guards the
square with the pawn at c7, which (a brief
examination reveals) cannot be pinned, captured, or effectively distracted. White nevertheless imagines playing the fork and losing
the knight. With the knight off the board and
Black’s c-pawn moved to b6, is anything interesting possible?
Dg063: White to move
Dg062: White to move
White has one check―Qe8―but it just loses
the queen. He has no more knights he can use
to fork anything. But here as in the previous
example he sees that Black’s king and queen
are on the same line—this time a diagonal. He
thinks “pin,” again, and can impose one with
Be6, winning the queen. (Black replies Ne5,
which will allow him to retake White's bishop
after BxQ; then White has Qxg6.)
Here the key thing to visualize was White’s
own knight cleared from the board. The
alignment of Black’s king and queen already
was present; the fork serves just as a way for
White to move his knight out of the path of
his bishop, and in a manner that forces
Black’s response before he can take measures
to avoid the pin that follows. One of our general points repeats: in addition to examining
every check you would have after an exchange, look for any newly open lines that
might allow for a pin or other tactic.
Dg063: This position is still more demanding.
A scan of the pieces on dark squares turns up
a knight fork: Nxc6, attacking Black’s queen
and his bishop; the latter piece makes a suitable target because it is unprotected.
But one must always ask what the response to
the fork might be, especially when neither of
the forked pieces is a king. Here Black has a
clear saving move: Qc7, both taking the
queen out of danger and enabling it to protect
the previously unguarded bishop. As usual,
however, this is no reason to give up on the
idea. Once Black makes his reply, a new color
scan or other examination of knight moves
would be in order: now White’s knight would
be on a light square and so would Black’s
king and rook. So how about Ne7+? Alas, the
square is protected by Black’s queen, now (in
our imaginings) sitting on c7. And yet this
still is no reason to give up on the idea, since
we always can ask what becomes possible if
Black then captures the knight. What lines
then would be opened? What pins would
come into existence? With White’s knight off
the board and the Black queen ending up back
at e7, White’s e1 rook would pin Black’s e6
pawn to his queen. A pinned pawn can guard
nothing, and in this case the pin leaves
Black’s rook at f5 unprotected. White takes it
with his queen.
This sounds complicated, and at first it isn’t
easy to see. But you might be aided by observing a visual pattern trying to emerge. If
White’s knight could vacate his square,
White’s rook would pin the pawn that protects
Black’s rook, which could then be taken. The
forcing way for White to vacate his knight
from e5 is with a fork at c6. Unfortunately
Black’s queen then moves, ruining the pin
White is trying to achieve; fortunately, White
can draw the queen back into place at e7 with
another knight move to that square. So solving this problem might involve two trains of
thought: one that sees a goal and tries to reason toward it (here, creating the pin so the
rook can be taken), and one that involves
looking at various attacks you can make and
what their consequences would be.
within fresh striking range of a knight or other
piece. Let's turn to examples.
2.1.9. Checking the King into Position.
In all the positions so far a knight has been
one move away from striking at two pieces.
We now turn to cases where that is not yet so.
Whereas the previous positions typically relied on pattern recognition—you see the
structural pattern for a fork in place and look
for ways to perfect it—the positions here involve the other side of tactical play as well:
examining forcing moves to see where they
lead. Most often we will begin the train of
thought by examining checks and their consequences. Checks are the most forcing of all
moves because the choice of replies to them is
so limited: your opponent has to reply by capturing the piece threatening his king, or by
moving his king, or by interposing something
between his king and your threatening piece.
And often one or two of those options will be
unavailable, reducing more the number of
replies you need to worry about.
Pushing your opponent’s king around with
checks is a good way to generate tactical opportunities. Eventually the king may end up in
position to be forked (or be used to create a
pin, or a skewer, or a discovery—as we shall
see later). We already know that kings are
ideal targets for double attacks, because when
your opponent is in check he rarely will be
able to use his next move to launch a counterattack. This point makes it easier to find forking ideas in the first place; for even if there is
no fork yet in sight, you always can ask
whether your knight is positioned to attack
your opponent’s king. If it is, then one of your
background goals as you play with your forcing moves is to move another of your opponent’s pieces onto a square of the same color
as his king’s, and into a position where you
can administer a fork. Likewise, anytime you
deliver a check that forces the king to move,
consider whether the king has been brought
Dg064: White to move
Dg064: In the position White has no forks, so
start by examining every available check. Ask
piece by piece whether you have any way to
attack the king and what would happen if you
did—what move would be made in response
and what the board would look like afterwards. Here White has just one: Ra8. It requires Black to move his king to g7. Now
imagine the resulting position and ask what
could be done with it—by use of a color scan
or by looking for your next check. Either way,
see that 2. Ne8+ forks and wins the queen.
Dg065: White to move
Dg065: It would be tempting to play the simple QxN for free here—and erroneous. Don’t
play any capture, not even of a loose piece,
until it’s clear that you can’t do better. Among
other things this means examining checks you
can give and their consequences. White has a
few with his queen; the most interesting is
Qe8. Black’s king is forced to a7 (the White
knight seals off b7)—and now rethink the
board and ask if new tactical strikes might
have become possible. With your knight so
prominently posted it is natural to look for
forks it might inflict, which train of thought
leads to Nb5+. White wins the queen for a
knight.
forks bishop and king. Notice that Black had
thought the White knight was pinned to
White’s queen, but since Ne5 is a check Black
has no time to take advantage of this; he has
to move the king, and then loses the bishop.
Another point to note: the bishop is protected
by the Black knight at f6. Do you care? No,
because after Ne5 the bishop also is attacked
a second time by White’s queen; so if Black
recaptures with NxN, White plays QxN and
still is ahead a pawn. The question is not just
whether a piece is protected; it’s always how
many times it is protected compared to how
many times it is under attack.
Dg066: Black to move
Dg066: A quick color scan shows that Black
has no potential forks to perfect, so start by
examining every check. Here there is just one:
Rxh2+. How would White respond? If he
moves the king to f1 or g1, examine the resulting position: he loses his d2 rook to RxR
(a skewer). So presumably he will instead
play KxR. Examine the resulting board.
Black’s knight will be on the dark square
where it already sits; White’s rook and king
will be on d2 and h2, respectively. So Black
then forks them with Nxf3+ and gets back the
rook (as well as the two pawns captured along
the way).
Dg067: White to move
Dg067: A common sort of position. Again
White has no potential forks, but as a matter
of course we examine every check. Here there
is only one: Bxf7+. Black can reply KxB or
Kd7. Then what? Redo the color scan: now
White’s f3 knight, Black’s g4 bishop, and
Black’s king all are on light squares. Ne5+
Dg068: White to move
Dg068: Black’s king is trapped; it can't escape
to g6 if it's pressured from behind. A natural
idea for White thus is Qe8, preparing for the
kill on h8—but Black’s bishop guards the
square, so White has to look elsewhere for
ideas. Start by examining every check. There
is just one: Rh8. And Black has only one reply to this: KxR. Now reexamine how the
board will look. White’s knight and Black’s
king and queen all will be on dark squares,
inviting the fork Ng6+. You could have arrived at the same conclusion by noticing that
White can attack Black’s queen with Ng6 and
asking whether there is any way to draw
Black’s king onto the square at the other end
of the fork, h8. A common way to move an
enemy king onto a square where you want it
is to put one of your pieces on the square,
attacking the king and requiring it to move
onto the square with a capture to defend itself—a decoy. Here the White rook can do the
job.
KxQ). This last sequence is the most interesting one. Why?
Dg069: White to move
Dg069: Start by examining the consequences
of any checks you can give: our modus operandi. There are four: Ne6 (does nothing), and
Qf8, Qg8, and Qh8. Qf8 can be dismissed
immediately as it results in RxQ with no gain.
Qg8 is unhelpful because it is met with KxQ,
drawing the king to a light square; since all
White has is his knight, and since the knight
and Black’s queen already are on dark
squares, it should be obvious that you would
like to draw Black’s king onto another dark
square as well. Qh8 accomplishes the mission, forcing KxQ (if the king instead moves
to g6 or h6, White plays QxQ, as should be
obvious if you are visualizing the White
queen on h8; it’s yet another skewer). Now
the White knight and the Black royals are
arranged for a fork via NxR+.
Another way to see this would be to start with
the knight and notice from the pattern of its
relationship to the Black king and queen that
it is just one move from attacking either of
them, but that they cannot be attacked at the
same time. To achieve a simultaneous attack,
one of them would need to be drawn onto a
different dark square. This can be done by
moving your queen to a square where you
want the king to move, and from which your
queen gives check (and skewers the Black
queen to boot, thus requiring Black to play
KxQ and walk into the fork).
Dg070: White to move
Because it forces the king to move, which
often creates new tactical openings. Here it
results in the Black king and queen and White
knight all being left on dark squares; there is a
fork at f7. But wait: what is Black’s reply to
2. NxR+? He can play Ra7xN, in effect trading a rook for White’s queen and knight! The
problem for White, of course, is that the forking square (f7) isn’t safe. We have ways of
handling that, however: here, start by taking
the piece on the forking square in some other
way and see if the piece that replaces it after a
recapture might then be loose. Hence White
plays 1. BxR, RxB; then comes 2. Qh8+,
KxQ; 3. NxR+, forking and then taking
Black's queen. White wins a queen and two
rooks in return for a queen and a bishop.
Dg071: White to move
Dg070: Start by examining every check you
can give. There are three: BxR (leads to
RxB); Qg7 (leads to QxQ); and Qh8 (leads to
Dg071: Standard procedure starts with an
inspection of any checks you can give. One of
them is Nc4. On a board so open you might
be tempted merely to conclude that the king
then gets away, but don’t be satisfied so easily; try to figure out where it will go. It’s easy
here because many of its apparent flight
squares are unavailable (e.g., d4, d5, or e6).
Indeed, Black has only two possibilities: Ke4
or Kf5. Now look for your next check—or,
since you are playing with your knight, look
for a fork. If Black plays Ke4, you have
Nd2+; if he plays Kf5, you have Ne3+. In
either event you win the queen next move.
The important lesson is to observe how improbable a knight fork might have seemed in
the original diagram given the distance of the
knight from Black’s queen. It turns out that
two jumps of the knight can cover a lot of
ground; if the first of its moves requires a
forced response from your opponent, you may
end up with a fork on the other half of the
board from where you began.
which it could be forked at the same time,
White would have the game. Does Qh8+ accomplish this?
Dg073: White to move
No; Black replies BxQ, and anyway if the
king were to move to h8 it would be too far
away from e6 for White to fork with his
knight. What about Qh7+? The difference is
that the queen would be guarded by White’s
knight, which also attacks f7. Thus Black
would have to move his king to f8—and into
a fork. White plays Nxe6+ and wins the
queen.
Dg072: White to move
Dg072: Start by examining every check, however briefly. There are two. The first, Qxf5,
loses the queen, so the follow-up had better be
spectacular; and it isn’t. But then there is Rh6.
Consider Black’s possible responses; visualize the rook on its new square. If Black moves
the king out of the way—say, to g7, or g5
(taking the knight)—White wins the queen by
playing RxQ (another example of a skewer).
So assume Black will play KxR. Now how
will the board look? White’s knight will be on
a dark square, along with Black’s king and
queen, which can be forked with Nf7+. So
Rh6+ effectively wins the queen.
Dg073: Start by examining every check you
can give. There are two: Qh7 and Qh8. As
you examine these, you also should notice
that White’s knight can strike against the
Black queen in one move—Nxe6; if Black’s
king could be forced onto a dark square on
We aren’t finished. Black of course must
move his king once it is forked, so press farther and ask where it will go. Moving it
backward along the back rank is out, because
White’s queen is there. He has to play Kf7.
Does White then have any more checks? Yes;
among others he has QxB—which is mate.
The moral of this part of the tale is that when
you have two pieces in the vicinity of the enemy king, and especially when one of them is
a knight, always be mindful of the relationship between the pieces—how one can protect
the other in an attack, how the knight can seal
off escape squares in different directions by
virtue of the odd shape of its moves, and
whether the ultimate goal—checkmate—thus
might be achieved.
Dg074: At present Black has no forks; only
one White piece is on the same color square
as his knight. It might be natural for Black to
consider Nh3, creating a threat of mate next
move with Qf2 or Qg1. But then you think
about what checks White would have in reply
and notice Qc8+—a queen fork that would
win Black’s knight on h3.
you picture the outcome of the exchange you
realize that it leaves Black’s king and queen
on light squares, just like White’s knight; or
even without that observation you simply
look for your next check and observe that
Ne7+ forks Black's king and queen, winning
the latter.
Dg074: Black to move
So Black scratches that idea and starts by examining every check of his own. There are
three: Qd1, Qf2, and Qg1. Qd1 loses the
queen without accomplishing anything. Qf2
forces White to reply KxQ and almost leads
to a knight fork at d3, but the square is protected by White’s bishop. Qg1 also forces the
reply KxQ, but it moves the king to a different
dark square. Now Black can launch a fork
from e2, which is occupied but unprotected;
NxB+ thus wins the queen a move later.
Dg075: White to move
Dg075: Start by examining every check.
There are three: Ne7 (resulting in QxN; forget
it), Rb8, and Rxc6. Rb8 leads to KxR, which
is of no use to White; here as in the previous
example, all White has is his knight, so drawing the king to a square of a different color
doesn’t help. But what about Rxc6? As usual,
one must actually visualize the Rook on c6 to
see all the effects of moving it there. In addition to checking the king, the rook then attacks Black’s queen; so if Black moves his
king, RxQ. Black thus has to play QxR. When
Dg076: White to move
Dg076: You know the drill: start by examining every check. There are three to find—
Nh6, Ne7, and Qg4. Start with 1. Nh6, which
forces Kh8 or more likely Kg7. What check
can White then play? If he tries 2. Qg4+, then
Black plays KxN. So 1. Nh6+ doesn’t look
very fruitful, at least on inspection of where it
leads anytime soon. And Ne7+ just loses the
knight. But then there is 1. Qg4+. If Black
responds by moving his king, White can play
2. Qg7 and mate. Since moving the king
therefore is out of the question and Black has
no way to capture the threatening queen, his
only remaining option is to interpose something in front of his king. He has to play Qg6.
Pause to visualize the resulting position and
ask whether you can do anything with it. Yes,
the Black king and queen are now arranged to
be forked by the White knight via Ne7+.
Another train of thought leading to the same
outcome might start by observing that
White’s knight on f5 attacks the g7 square in
front of Black’s king, which is exposed; this
suggests the possibility of mate if White can
get his queen onto g7. The natural route to
that result starts with Qg4, putting the queen
on the right file. Black’s response is forced:
Qg6. Then you see the fork.
board would look, and see that it would invite
a fork of king and queen via Nf7+. Again, you
might have been helped along in seeing this
by observing from the start that White can
attack the Black queen with one move of his
knight and wondering whether Black’s king
might be forced by a check onto the dark
square at h8 where it could be forked.
Dg077: White to move
Dg077: Start by examining every check
White can give. There are four: Ng6, Nf7,
Qxh7, and Rf8 (don't forget to consider every
attacker). The knight checks are important
because they show you that Black’s king can
be attacked with the knight in just one move;
they suggest that White might have a crushing
fork if Black’s queen could be forced onto a
dark square. Qxh7+ just loses the queen and
doesn’t help the forking prospects. Rf8+,
however, permits only one reply: QxR. Visualize the resulting position and see that it calls
for a knight fork at g6. Ask whether the
square is protected and see that the h7 pawn
appears to be on the job—but it’s pinned.
White wins a queen for a rook and a knight.
As noted, Black has one alternative to moving
his king to h8 in response to Bd5+: he could
interpose his f8 knight by playing it to e6. But
if you ask what checks White then would
have, you see that in addition to BxN+ he
now has the better move QxN+, capturing the
knight that had previously prevented him
from checking with his queen. This would
again force Black’s king back to h8 and allow
White's knight fork on f7. (With his own
knight out of the way, Black also would have
the option of playing Kf8, but this leads to
mate on the move for White with Qf7).
The reason White should reply to 1. Bd5+,
Ne6 with QxN rather than BxN is that if he
captures with the bishop, Black’s move of his
king to f8 works after all; there is no mating
threat because White’s queen still is back on
e2, stuck behind the bishop now at e6. The
general point is that after administering a
check and seeing a response that leaves you
short of your goals, examine all remaining
checks rather than rushing to re-administer
check with the same piece you used the first
time. Bringing your queen into your attack
can be a particularly potent move, as this position shows.
Dg078: White to move
Dg078: Start by examining every check.
There are two: Qe6 and (less obviously but
critically—examine every piece!) Bd5. Qe6+
loses the queen to NxQ. Bd5+ is more interesting. The bishop can’t be taken by any of
Black’s pieces, and Black can’t move his king
to h7 because of White’s knight. So Black has
to play Kh8 (actually he does have one other
option we will consider in a moment, but let it
pass for now). Now ask how the resulting
Dg079: White to move
Dg079: Start in the usual way: examine your
checks and their consequences. All the checks
White has here involve its queen, which can
attack the king by moving to b6, d6, c5, c4,
c3, or g7. Four of those moves lose the queen
on the spot, but 1. Qc4+ does not. Black can’t
capture White’s queen in response, so he
would have to either move his king or interpose something. Which will it be? Don’t just
think of the queen moving to c4; imagine it
there—and see that it also would be attacking
Black’s rook, which is unprotected. Black
would like to avoid the loss of his rook, and
so might play Kd7 to protect it while also
moving his king out of harm’s way. Now how
would the board look? White’s knight is on a
light square; so are Black’s king, queen, rook,
and bishop—all of which can be forked from
c5! The only apparent difficulty is the Black
pawn at d6, which protects the needed square.
But an early question about any such case is
whether the protecting piece is constrained by
a pin, and the d6 pawn is indeed pinned to
Black’s king by White’s rook. So 2. Nc5+
wins the queen.
If Black doesn't fall for this by playing Kd7 in
the first place, then of course White instead
uses his second move to take Black's rook. It's
an example of a queen fork, which is a theme
we will study in detail soon, but the general
point already is familiar: sometimes a knight
fork (or any other tactic) does its work without ever being carried out. The threat of it
forces your opponent to cough up material to
avoid seeing it executed. To put it differently,
you don't play a move like Qc4+ here hoping
that Black will play Kd7. It's great if he does,
but you should always assume he will see the
trouble coming and will play the best move
available to him—probably Qc6, but in any
event not Kd7. We say the sequence works
here not because we fantasize that Black will
play Kd7, but because you are sure to win at
least a rook if he plays anything else. Alas,
many of the prettiest forks never end up getting played.
Going back to the main idea of the position,
the tricky part is that the fork depends on the
pin of the d6 pawn, which is visible only if
you clearly are imagining both White’s move
(Qc4+) and Black’s response (Kd7). It is a
perfect example of the importance of visualizing not only the move you imagine making
but also the move that comes after it.
2.1.10. Using Multiple Checks.
The skill called for in that last problem—the
ability, when you examine a check or other
forcing move, to keep the resulting appearance of the board clear in your mind’s eye—is
one of the keys to good chess. It gets even
more important as we turn to positions that
require you to follow up on a first check with
a second one before the fork is ready. Gradually your ability to recognize an emerging
forking pattern will kick in as you are examining the checks and follow-up checks available to you. By working back and forth between forcing moves and glimpses of patterns, you build a combination. Start the following position.
Dg080: White to move
Dg080: Anytime you have a battery of rooks
on an open file like this, consider what would
happen if you drove them both through to
your opponent’s back rank. Sometimes the
result may be a mating sequence there; even if
not, though, the threat is powerful enough to
force results—and forced results always have
to be inspected in search of forks or other
tactical opportunities they may create. Thus
White imagines Rc8+, to which Black would
reply NxR; then comes RxN+, and Black’s
king is forced to f7. If you were looking only
for checkmate you would have to consider the
sequence a failure, since the king escapes. But
if you're looking for a tactic the sequence is a
spectacular success, as it leaves Black’s king
and queen both on light squares and ready to
be forked with Ng5+. White wins a queen and
a knight for a rook and ends up with two attacking pieces on the board against none.
Notice how remote the chances for a knight
fork by White appear to be on the face of this
position; the knight on f3 just seems too far
away from Black’s king. It’s a study in the
importance of reevaluating such possibilities
whenever you can make the enemy king
move. A useful rule of thumb is to ask every
time the king moves whether you have any
new checks against it. Here that would turn up
Ng5 on White’s third move.
swer with RxQ; but rather than abandon the
idea, follow it through: then what check can
White play?
Dg082: White to move
The obvious follow-up is RxR+ (exhausting
the battery on the f-file), and again the response is forced: KxR. The result of this sequence will have been the loss of White’s
queen and rook in return for Black’s rook, but
also—and most importantly—the movement
of Black’s king to f8. Black’s king and queen
would then be on dark squares; NxB+ forks
them, and after winning the queen White has
gained a piece (the bishop captured by the
knight).
Dg081: White to move
Dg081: Start by examining every check.
There is only one: Ra8+. Black must defend
himself. He has no way to capture the rook
and can’t move his king because both of its
flight squares are attacked by White’s knight.
All that’s left is to interpose his bishop at d8.
Now what next for White? Look for another
check. Again there is just one: RxB+. If Black
responds with KxR the board looks even simpler than it did at the beginning: Black rook at
h8; Black king on d8; White knight on e5.
The fork at f7 is self-evident.
Dg082: The most natural moves to consider
here might be Nxb7, picking up a pawn, or
Qf7+, safely giving check and perhaps starting to hunt the king. But White can do better,
and you will see this only by considering less
obvious checks and their consequences. In
addition to Qf7+ White also has Qf8+. This
loses the queen, as Black is required to an-
Dg084: White to move
Dg084: Start by finding every check White
can give. There are four: Qxe6, QxB, Nf6,
and Ne7. The first two lose the queen and
have no good follow-ups, but Nf6+ is interesting; Black can’t respond with BxN because
his bishop is pinned by White’s queen. So
Black must move his king. Now ask if White
will have another check after the king moves.
Notice that whether the king goes to h8 or f7,
White can play QxB+. Either way Black has
the reply KxQ. So then his king will be where
his bishop now sits, on g7—at last on a dark
square; and your knight will be on f6. Since
your only plausible attacking piece is your
knight, you naturally are on the lookout for a
fork. In the resulting position you find it at e8.
After taking Black’s queen, you’re up a
bishop.
Dg086: Start by examining every check.
(Again, it's drill.) There are three: Nxa7, or a
move of either knight to d6. Nxa7 loses the
knight to NxN without a good follow-up.
Moving either knight to d6 results in BxN, but
White then can recapture with another check:
NxB+. With his ability to capture on d6 now
exhausted, Black would have to move his
king out of check to b8 or c7. Then what?
You could look for yet another check using
White’s bishop, with inconclusive results. Or
you could notice that White’s remaining
knight then would be on a dark square and
that Black’s rooks both would be on dark
squares, too. Nf7 forks them and wins the
exchange. This time the point of the checks
wasn't to move the Black king into position to
be forked. It was to keep Black busy with
threats he had to address while you prepared
to fork his rooks.
Dg085: White to move
Dg085: Your only piece that can do any
checking is the queen, at g7 and g8. There is
no apparent follow-up if it goes to g8 and is
taken by Black’s king. But now suppose
White plays Qg7 and look at the resulting
position. Notice the significance of the pawn
at f6; it means Black would have no choice
but to play QxQ. You still are thinking in
checks, so look for the next one and arrive at
the natural recapture f6xQ. Again Black then
has only one legal move: Kg8. Continue to be
relentless in looking for the next check and
you come to Ne7+—a fork of Black's king
and c8 rook. White nets a rook with the sequence.
Dg086: White to move
Dg087: White to move
Dg087: White has no forks yet in view, so
start by examining every check. The queen
has several—Qxh6, Qh8, Qg8, Qg7, Qf7, and
Qe7. All of them lose the queen without creating a good fork. But there is one more check:
Bxg6. How would Black respond? With KxB.
Still no fork would be possible, but once the
king moves you naturally reconsider the
checks you can give and their consequences.
(As you do it, bear in mind that the knight on
d4 already can attack Black’s queen from e6,
and so will have a fork if the king can be
forced onto g5 or g7; this is an example of
working back and forth between ideas based
on pattern recognition and experiments with
checks.) The interesting new check White has
is Qf5—interesting because the queen attacks
the king and is protected by the knight.
Black’s only legal reply is Kg7. Again, with a
move by the king you reevaluate your tactical
options. Now the king and queen sit on forkable squares; Ne6+ forks and wins the queen.
This position is a little tricky because it takes
a moment to see that White's key move (2.
Qf5) forces Black's king to g7. Learning to
see where the king can and can't go when it's
checked takes a little practice.
Dg089: White to move
Dg088: White to move
Dg088: White has three checks to analyze:
Qe7, Qf8, and Bxe6. The two queen checks,
in response to either of which Black plays
KxQ, almost create opportunities for White’s
knight to fork the king and queen, but not
quite; the forking square (e6) is protected in
either case. So consider Bxe6+. Black's likely
reply is BxB (we will consider an alternative
in a moment). Now ask what checks you then
would have, and you are returned to the same
two queen checks mentioned a moment ago.
Qf8+ requires KxQ (notice that the king can’t
move to g6), leaving the Black king and
queen on dark squares along with White’s
knight. The forking square (e6) no longer is
protected by the bishop; now the bishop is on
e6. So 1. NxB+ works for White, netting a
pawn. Notice the repeating pattern in the
thought process involved: find a check; consider the response; look for another check, all
the while keeping the changes occurring on
the board clear in your mind’s eye and watching out for forks.
After White's initial Bxe6, Black has another
option: Ke8. But now he immediately loses
another pawn to Nxd5, with more complications to follow; so BxB is less costly.
Dg089: Actually this one doesn't involve two
checks, but it fits here because it does involve
the search for a check after another forcing
move. The trouble from the outset is that neither of White's available checks are productive (Be6+ loses the bishop; Qxd5+ loses the
queen). Still, White sees that his knight is
close to being able to deliver a game-ending
fork at f7: there it attacks the queen and would
attack the king if it could be driven into the
corner at h8. Since checks don’t seem helpful
in producing this result, White considers the
next prominent way of forcing changes on the
board: captures. The most prominent piecefor-a-piece capturing possibility is BxN,
which leads to h7xB. The important question
about such an exchange, of course, is what
does it leave behind? What open lines? It
opens the h-file, so ask anew what checks are
possible and with what consequences. There
is a fresh one: Rh8+. Black has to play KxR
in reply (White’s knight guards the king’s
flight square at f7); the check at h8 sucks the
king onto that same square.
So now the king has moved, and whenever
that happens you ask what checks have become available—especially given that the
knight has been waiting to administer a fork
at f7. Indeed, Nf7+ is White’s only check then
remaining. It wins the queen. (Black moves
his king, and White plays NxQ. Now Black
recaptures BxN; and if the Black move of his
king was to g8, then White now has the queen
fork Qxd5+.) What all this means is that the
original BxN wins a piece, as Black cannot
afford to recapture h7xB. As we have seen,
that often is the significance of seeing a fork:
not that you get to play it, but that you are
able to make material gains because you realize (and your opponent realizes) that if your
captures are avenged by your opponent he
ends up the victim of an even worse double
attack.
Incidentally, it might have occurred to you
that Black could reply to White’s 1. BxN with
1. …QxB, but this is worse. The problem for
Black is that White then plays 2. Qxd5+
(again, always looking for the next check) and
now has tremendous pressure against the
Black king's position. The pressure may not
result in immediate mate, but it produces
heavy casualties:
(a) If Black moves his king to h8, White has
3. Rxh7+, which requires the Black queen to
take the rook on h7 (the king can't move)—
and then the queen gets taken by White’s
knight: 4. NxQ. (If Black recaptures KxN on
h7, White has a queen fork: 5. Qh5+, which
wins the rook on e8 and leads to mate soon
after. This last kicker might be hard for you to
spot, because you have to see that by the fifth
move the White queen would have clear paths
from d5 to h5 and from h5 to the rook on e8.
But just seeing that Black loses his queen is
enough for now. (White also can do at least as
well—maybe better—by playing 3. Nxh7, but
let that pass for now; it's more complicated..)
(b) If Black instead replies to Qxd5+ by moving his king to f8, White has Nxh7+ and
Black again must sacrifice his queen with
QxN to put out the fire. (If Black instead replies to Nxh7+ by moving his king over to e7,
White plays BxBc5+; now Black’s only legal
option is to interpose his queen on d6, losing
it next move and getting mated soon after.)
There are some other possibilities, but White
does pretty well in all of them. White also
does nicely by starting with Qf3, but that's a
tale for another time.
Some of those variations sketched a moment
ago take a little time to see. The trick to them
is to think relentlessly about what checks
White might play in response to each of
Black’s moves.
2.1.11. Using Mate Threats to Force Pieces
into Position.
Now we're going to consider a few positions
where the elements of a fork are brought into
being by a judicious use of mating threats.
These studies will be pretty hard, at least by
comparison to those we've seen already; peruse them for the ideas involved. The whole
question of the tactical use of mating threats
will be explored in more detail, and in a more
step-by-step fashion, in the next chapter (on
queen forks).
Dg090: Black to move
Dg090: Prospects for a knight fork for Black
might seem remote in the position to the left,
but it turns out to be easily accomplished.
Begin by thinking about the enemy king and
any pressure you can put on it. Ng4 is interesting because it seals off f2 and (more to the
point) h2, leaving the White king trapped on
the back rank just as it would be if there were
a wall of pawns in front of it. You look for the
follow up and see that Black would then be
ready to mate with Ra1+ (White would have
the useless interposition Rd1, to which Black
replies RxR#). Now of course after Black
plays Ng4 White has a move he can use to
fend off the coming Ra1+; he plays Rd1, thus
preparing to meet Ra1 with RxR. What now
for Black? Anytime your knight is in the picture and enemy pieces have moved, consider
forking possibilities. From g4 the knight
would be able to jump to f2 with check and
take the rook for free next move.
The trick to the position is to carefully look
not only for any checks but also for any mating threats you can create - not necessarily
because you expect them to lead to mate, but
because you know they can create pressures
that have tactical payoffs. A search for mating
threats includes consideration of any move
like Ng4 that, while not giving check, traps
the enemy king in a tight space. Then you
figure out what your opponent would have to
do to defuse the threat, and ask whether any
forks or other tactical moves would be possible on the board as it then would look.
Dg091: Black to move
Dg091: This position closely resembles the
last one; but here each side has an extra piece,
and the one that matters is White’s bishop on
c7. Now if Black tries the same beginning
move discussed in the prior position—Ng4—
White has a better way than Rd1 to fend off
the threat of Ra1#. He can instead play Bb6,
preparing to meet Black's Ra1 with Bg1,
which would effectively block the check. So
Black needs another idea.
does move his king to h2, another dark
square, Black can skip Rh1; instead he wins a
rook with the knight fork Nf1+.
(b) White’s other option in reply to 3. …Ne3
is to step his g3 pawn forward to g4, giving
the king a flight square to the side. Now
Black plays 4. …Rh1 and White has 5. Kg3.
Again, though, this puts White’s king onto a
dark square and allows Black to win the rook
with the knight fork Nf1+.
This whole sequence also was available in the
previous position; if you saw it there, great.
The point is that here you would have to use
it. The shorter fork described in the previous
frame no longer works. In a sense, though, the
lesson of this position is the same as in the
prior one: think about checks and mate threats
you can create, not just on the board in front
of you but also on the board as it will look
after a check or two or after some other set of
forcing moves. Here this means seeing 3.
…Ne3, which doesn’t give check but does
threaten mate and so forces White to choose
between two moves that each lead him into a
fork. When your knight is hopping around as
Black's does here, you especially want to
think about forking possibilities at every turn;
3. …Ne3 not only creates a mate threat but
also puts the knight on a dark square along
with White’s rook, meaning that Black can
fork the rook if White’s king steps onto one of
its available dark squares as well—as it soon
must.
The natural alternative to explore is an immediate 1. …Ra1+, forcing White’s king to h2.
Black then looks for his next check and finds
2. …Ng4+, forcing the king up another square
to h3. Now watch this: Black plays 3.
…Ne3—not a check, but renewing the threat
of mate via Rh1 since the knight now seals off
g4 and keeps the White king trapped on the h
file. White somehow has to find an out for his
king. Moving it to h4 won’t do; that still
leaves no safe square after Black plays Rh1.
But White has two other choices.
Dg092: White to move
(a) The first is Kh2, readying the king to capture the rook if it moves to h1. But keep track
of the Black knight’s position: it has moved
twice and is on e3, a dark square. If White
Dg092: White has limited resources, but one
of them is a knight on e5 that can give check
with Nxf3 or Nxg4. Those checks are of no
use now, but they're important to see because
they mean the knight is poised to deliver a
fork if one of Black’s pieces can be lured onto
another square that the knight is able to reach
from f3 or g4. Another way to put the point is
that any other squares the knight can reach
from f3 or g4 may now be very safe for White
to occupy with one of his other pieces (he
would be happy to see Black perform a capture there and walk into a fork). Since White
only has one other piece, a rook, the natural
thing is to experiment with places it can go
that take advantage of this forking potential.
There is one such square: f6. If Black replies
to 1. Rf6 with QxR, he gets forked with Nxg4
and loses his queen.
Well, so what if Black doesn’t play QxR? The
first way to explore that question is by asking
what checks you next would have—and seeing Rh6, which turns out to be mate. (Notice
how constrained Black’s king is.) So actually
Black does have to play 1. …QxR to avoid
the mate threat, and this results in the aforementioned knight fork.
Once you understand White's mating idea
here, it might occur to you to start instead
with 1. Rxg5. This, too, puts White one move
away from mate on the h-file (with Rh5).
When you look for ways Black could fend off
the mate, you see Qh6—and realize that this
would arrange Black's king and queen to be
forked with Nxg4+. Indeed, this achieves the
knight fork without giving up a rook at the
beginning, so at first blush it looks better than
the brazen Rf6. But there is a catch. Are you
sure Black would walk into the fork by replying to Rxg5 with Qh6? Rxg5 is a formidable
threat, but it isn't a check, so Black has some
freedom in replying to it. Consider not only
Qe8 but the possibility that Black can go on
the offensive with Qb6+. White is pretty
much forced to play his king to e1 (Kf1 results in Qg1#). And then Black holds the initiative with another check: Qe3+—and notice
that this is a queen fork of the rook now on
g5, which White is about to lose. And then
White has to worry about the Black f-pawn
promoting, and will have to sacrifice his
knight to stop it. (Starting with Rf6 avoids the
mess just described because it puts the rook
on the sixth rank, allowing it to reply to 1.
...Qb6 with 2. RxQ.)
So the short of it is that starting with Rf6 wins
the game for White; Rxg5, which looks safer,
loses it. To reiterate the crucial train of
thought, you might overlook the resource
Black has in 1. ...Qb6 by focusing too much
on how he can defend against mate, since
from that perspective Qh6 does seem to be his
only move. The key, again, is to ask not just
about defense but about what counterthreats
Black might try, and especially what checks
he can give (Qb6)—and then what further
checks (Qe3 or Qg1). That's the biggest difference between working with checks and
working with mate threats: they both force
your opponent's replies to some extent, but
the mate threat gives him the option of seizing
the initiative if he can find a way to do it; so
you must ask if he can.
Going back to the original idea, of course you
might have seen it not only by thinking about
your knight check but also by starting with
the stuckness of Black’s king; it has no safe
escape from the h-file. This makes you think
of putting a rook onto the h-file, but it’s hard
to get it there because Black has a queen positioned to defend against any such effort. Yet
for the sake of argument you go ahead and
imagine 1. Rf6, QxR—and then see that this
puts Black’s king and queen both on dark
squares, enabling them to be forked with
Nxg4+.
2.1.12. Strategic Implications.
Your first question before making almost any
move is whether there is a tactical opportunity
for you on the board. If there isn't—as routinely will be true—then your choice of move
will be determined by strategic considerations: attempts to secure positional advantages
that may ripen into tactical opportunities. One
goal of strategic play is to create the types of
positions where tactics, such as the double
attacks we have studied, become possible. It
is not the purpose of this site to advise you on
effective strategy in any depth, but here are a
few elementary points on the subject, particularly as it relates to the knight.
A couple of general things first. It often has
been observed that good positional play leads
naturally—perhaps even mysteriously—to
chances for tactical wizardry. Why? The reasons have to do with what good positional
play accomplishes. The most important purpose of it is to expand the power and mobility
of your pieces—often the same thing, because
the power of a piece largely is a function of
how many squares it attacks, which in turn
will depend on its mobility. A rook on an
open file—i.e., a file containing no pawns—is
very mobile and for that reason very powerful. Likewise a bishop on an open diagonal.
So when you look at a piece and assess the
quality of its position, consider how many
squares it controls. A fully deployed army of
pieces will attack a large share of the squares
on the board, especially including squares in
your opponent’s half of the board, many of
them two or three times. A second purpose of
positional play, of course, is the converse:
limiting the power and mobility of your opponent’s pieces. The fewer the squares he
attacks, the greater your ability to put your
own pieces there.
These principles relate to tactics in obvious
ways. If your pieces have lots of room to
move and attack lots of squares, that means
they can range more boldly into parts of the
board where they can cause trouble to your
opponent; it also means you are more likely to
be able to coordinate them, bringing two or
three or four pieces to bear on a sector in
ways that permit a combination: perhaps sacrificing one, pinning with the other, and then
capturing or forking with the third. Note that
an individual piece does not threaten much
when it ranges into enemy territory by itself;
as we have seen many times, a knight usually
needs help from other pieces to set up a good
fork. Meanwhile if your opponent’s pieces are
constricted or blocked in their movements,
this does more than prevent them from causing you trouble. It makes them prey to tactical
strikes, because they give him fewer good
options in responding to checks, captures, and
threats that you make.
So when you aren’t playing tactics, think
about these two considerations: how you can
place your pieces to enlarge the amount of
territory (“space”) they attack and control;
and how you can place your pieces and pawns
to confine your opponent’s army. This partly
is a matter of simple gestures like moving
your rooks onto open files, getting your
knights and bishops off the back rank and out
where they can exert pressure down the
board, and keeping a pawn or two in the center so that your opponent can’t plant pieces
there and so that your pieces there are protected. It’s also a matter of subtler things:
exchanging pawns where the exchange will
create an open or half-open file for your rook
(but perhaps not if it creates such files for his
rook); placing your pawns (and keeping his
pawns) on squares that block the paths of his
bishops; and thinking about how pawn moves
and exchanges affect the lines open to other
pieces on both sides. These are general ideas
to consider when you are picking a move
without any immediate tactical purpose.
Against this backdrop consider the knight in
particular. The knight doesn't need open lines
because it jumps rather than slides. But it still
needs help from your pawns to be effective.
The first thing to grasp is that the knight’s
prospects for creating mischief tend to increase as it moves up the board. A White
knight on f3 early in the game serves mostly a
defensive purpose, and a valuable one (though
of course even this knight has offensive potential, as we occasionally have seen); the
same knight on, say, d4, d5, or d6 becomes a
terrible offensive threat. On d6 it strikes out at
eight squares, including six in your opponent’s half of the board; from any of the
squares just listed the knight can attack the
opponent’s back rank, and often his king, in
one move. (More than 90% of the knight
forks we have considered involved the king as
one of the two targets.) So an important general strategic aim is to get one of your knights
planted on a square on your fourth rank or
beyond. An especially good place to plant a
knight is on a square near the center, since
from there it can make threats and influence
play in all sectors of the board. This is why
chess books often speak of the importance of
controlling the center, and of the battles that
players wage to keep a pawn on the central
squares and to keep enemy pawns away from
there. The point is not necessarily that pawns
in the center themselves threaten anything; it
is that the pawns control the squares that they
can attack. When you have a pawn on e4 it
controls not e4 but d5 and f5. Enemy pieces
are unable to move to those squares; your
pieces can. Having good central squares on
which you can plant your pieces is important.
That is where they are most powerful.
Dg093: White to move
Dg093: The key word is “plant.” It’s not
much use to move your knight to a central
square only to have it chased away by a pawn.
You have to create a hospitable square - an
“outpost square”—for your knight. A good
outpost (d5 in the diagram) is a square where
the knight cannot be harassed by pawns, because the enemy pawns on either side of its
file are gone, are blocked, or have advanced
up to your knight’s rank or beyond it. Ideally
the well-posted knight also is protected by
one of your own pawns; that will prevent it
from being chased away by one of your opponent’s rooks or his queen. The remaining
point is to make sure the knight is not threatened by one of your opponent’s bishops or
knights. The White knight in the diagram has
all of the good properties just described. It is
planted in the center of the board on d5,
where it has two ways to check the Black
king. So long as the knight stays where it is it
will be a constant forking threat, exerting a
great influence over everything else that happens in the game. Notice the role of the pawns
here: White controls the knight’s square with
the pawn on e4; Black has no pawn that can
chase the knight away—and also no knight,
and no light-squared bishop. As a result, the
knight probably will be impossible for Black
to dislodge without a sacrifice. White had to
fight to create this position; for an account of
the battle, see Weeramantry’s first-rate book
Best Lessons of a Chess Coach.
The conditions of a good outpost square may
seem numerous, but creating them is a suitable task to keep you busy when you aren’t
playing a tactic. Some of them take care of
themselves; others require work. Realize,
first, that every time you move a pawn forward you weaken the squares it used to protect. If the pawns on either side of a square
have moved forward or are off the board, the
square becomes a hole where the other player
eventually can put his pieces, comfortable in
the knowledge that no pawn will be able to
chase them away. It is common for such holes
to be created inadvertently as each side advances and exchanges pawns. (In the diagram
here, Black allowed a hole to be created on d5
by moving his e-pawn to e5 and by allowing
his c-pawn to be removed.) This is a critical
consideration to bear in mind both offensively
and defensively. From an offensive standpoint, realize that the most important consequence of an exchange of pawns (or of any
sequence) sometimes can be to foul up your
opponent's pawn structure and leave holes
behind. On the defensive side, think carefully
about whether your pawn moves or exchanges
will result in holes that create outpost squares
for your opponent’s knights and other pieces;
place your pawns so that they guard (rather
than occupy) the attractive squares where his
knights might like to perch. A few pawns
well-placed in this way can neutralize a
knight quite thoroughly.
As for your opponent’s bishops, if one of
them is off the board, then squares of the
color the missing bishop used to patrol are
natural candidates for outposts. Likewise, if
you see a promising outpost square it is worth
hunting down and exchanging away the enemy bishop that travels on squares of that
color. If you then have to move a knight three
times to get it onto a good outpost square, it
may well be worth it. A knight often will not
be a big factor in a game—and will not be
able to make the types of moves seen in this
chapter—unless it finds a suitable outpost;
once it does find an outpost, it may dominate
the rest of the action. Even if you cannot satisfy all of these criteria for an optimal outpost
square, taking care of one or two of them—
creating the characteristic pawn structure in
particular—may create an outpost that is suitable for quite a while. (If you can’t get rid of
the bishop on the color of the outpost square,
for example, it may nevertheless be out of
position to do anything about your knight.)
And naturally a safe outpost may be easier to
create later in the game when there are fewer
enemy pieces on the board.
2.1.13. Summary.
The natural tendency of the mind when looking at a chessboard, as elsewhere, is to jabber
away with tangled thoughts. Effective chess
requires a different style of thinking: systematic, thorough, and aggressive. You want to
ask the right questions before you decide what
to do. There are, first, general questions that
must be considered routinely. As the great
Australian chess writer Cecil Purdy suggested, the most basic are “what does he
threaten?” and “what is his reply if I make
this move?” Also, and relatedly, “if I do this,
will I leave anything unprotected?” and “does
he have any checks that can cause me trouble?” There is no need to blunder away a
piece by leaving it unguarded if you are careful to interrogate the board this way as a matter of course.
The principles laid out in this chapter might
likewise be summarized into a sort of checklist. The goal of studying patterns is to internalize all this and think with your eyes, rather
than in a verbal flow chart, but as you are
getting started it helps to dwell on the questions that are helpful to ask yourself, with or
without words, before deciding what move to
make.
With respect to knight forks, the important
questions generally arise when you have a
knight in the same vicinity as some of your
opponent’s pieces, and especially within striking range of his king. Again, the order in
which the questions are asked is not particularly important, and will depend on the salient
features of the position that suggest themselves to your eye; nevertheless, the ones
most often important are these:
Do I have a potential fork? If so,
Is the square that I need protected? If so,
Is the protecting piece constrained? Is it
pinned, can it be pinned, or would it be
pinned after the sequence of moves I am considering? Can the protecting piece be captured, and then be replaced with a piece that is
less effective? Can I capture something that
the protecting piece guards, thus luring it
away from the forking square? If there is no
immediate way to do this, are there any sequences of exchanges that would have this
effect?
Can one of the pieces in the fork be captured
and thus exchanged for a more suitable target?
If I go ahead and deliver the fork and let my
knight be captured, what then becomes possible? What lines are opened, and what pins
created? What checks could I then administer,
and with what replies? Then what checks or
forks would I have?
If I don’t have a potential fork, can my knight
check the king? If so, can a valuable enemy
piece be moved onto a square that would be
forked by my check? If my knight can't give
check, what checks with other pieces now are
available to me? What are the responses required by each of them? What checks could I
then add, and with what responses? Do the
positions resulting from any of these sequences create chances for knight forks?
Let this chapter change the way you think
about checks and captures. Very often they
are usefully given not for their own sake but
because they require responses that change
the board and may then create good opportunities for double attacks or other tactical
strikes. So when you imagine making a capture, do not just ask whether your opponent
can recapture and write off the idea if he can.
Imagine what would be possible after your
opponent recaptures that might not have been
possible before. By the same token a check
that easily can be evaded hardly is worthless
for that reason; the point of a check commonly is to force the king to move or to force
other responses that eventually might make a
fork or other tactic possible. This basic principle—viewing checks and captures as ways
of changing the look of the board to create
other opportunities, rather than as ends in
themselves—is the essence of tactical thinking.
2.2. The Queen Fork.
2.2.1 Introduction.
Double attacks by the queen, like all others,
have certain repeating characteristics that follow from the value of the piece and the types
of moves it can make. Every chess player
knows to value the queen because of all the
different ways it can move. As students of
tactics in general and double attacks in particular, however, we can see the queen’s value
more precisely: purely as a matter of geometry, the queen can attack any two squares on
the board at the same time; if you put the enemy king on one square and another enemy
piece on another square, there is always a
third square from which your queen can, in
principle, attack them both. (In the skeletal
diagram to the left, White’s queen forks
Black’s king and rook.) We say “in principle”
because often the needed square will be unreachable or protected, or the lines from the
square to the king and loose piece may be
blocked by other pieces. But it is worth reflecting anyway on this feature of the queen’s
power. It helps explain why the queen surpasses all other pieces as a tactical weapon.
As a double attacker it has no peer.
The queen’s immense usefulness also limits
its power in this respect: it generally is too
valuable to trade for any other enemy piece
on the board. Of course the queen sometimes
may be sacrificed to achieve checkmate; you
may exchange queens, if the other is more
dangerous than yours; and very occasionally
you may give up your queen in return for a
large number of your opponent’s other pieces.
But usually it isn't worthwhile to use your
queen to take an enemy piece that is protected. Either the protection has to be eliminated or a different, loose target has to be
found. Notice the practical implication: usually at least one loose (i.e., unguarded) enemy
piece must be found or created for a queen
fork to be effective. This principle—the requirement of a loose piece—does not apply to
knight forks, because if a knight attacks a
rook or queen it makes no difference whether
they are defended; you gain just by exchang-
ing, because knights are less valuable than
those other pieces.
We can go farther. When your queen inflicts a
double attack, the enemy will have time to
move one of the attacked pieces; if neither of
them are his king, he usually will move
whichever is unprotected. That means that to
be effective a double attack by the queen usually has to attack either two unprotected
pieces or an unprotected piece plus the king;
for only then will there still be an unprotected
piece left behind for your queen to capture
after your opponent moves the more valued or
vulnerable target of the fork to safety. Attacking the king here has all the advantages that it
did when we studied knight forks: the opponent must attend to the threat, usually by
moving the king or interposing something,
thus leaving the other piece being forked to
get taken. (An additional possibility we will
consider, almost as good as attacking the
king, is threatening mate. This less often is an
issue for the knight than for the queen, because the knight less easily can make such
threats.)
Dg094: Black to move
Dg094: Here, then, are the key points to guide
your hunting: the targets for a double attack
by a queen usually include (a) the king—
either by a check or by a mating threat, and
(b) an unprotected knight, bishop, or rook.
You are looking for squares from which your
queen can attack two of those targets, or
where it might be able to attack them after
some preliminary maneuvers. From this we
can deduce a fairly manageable set of challenges to making queen forks work: the forking square is guarded; the line to the forking
square is blocked, or the line from the forking
square to one of the targets is blocked; the
king is not yet in position to be checked, but
can be brought into position; there is not yet a
loose piece at the other end of the fork, but a
piece there can be loosened or an already
loose piece can be forced there by threat or
attraction. In the next sections we will study
how to identify and solve each of these problems. The solutions to most of them involve
exchanges.
2.2.2. Simple Cases: Forking the King and
a Loose Piece.
We start with simple positions where the
queen is one move away from inflicting a
double attack. Even if you are new to queen
forks you may be able to see the solutions to
many of these right away. It’s still worth
studying them methodically so that your grasp
of the principles involved will be clear when
we move to more complicated cases. For
other readers double attacks with the queen
may be hard to spot at first; in the beginning
the board will look like a sea of pieces and
squares, with the queen coming out of nowhere to attack two targets. But in fact most
double attacks with the queen follow recognizable patterns, and these simple positions
will enable you to nail down their fundamentals before worrying about how to remove
obstacles to their execution.
In each position your task is to find a square
your queen can reach and from which it will
(a) check the enemy king and (b) attack a
loose enemy knight, bishop, or rook. So you
might begin by finding the undefended enemy
pieces on the board. Think of this as a basic
and ongoing part of your job during a game;
every loose piece is a potential target you
might be able to take for free with a double
attack.
Next, look at any checks available to your
queen. Sometimes this will be easy, but more
spectacular double attacks often require you
to notice checks possible from counterintuitive squares. It is good to be exhaustive.
Think of it this way: the queen can move in
both directions on the rank where it sits, on
the file where it sits, and on each of the two
diagonals where it sits. So it has a maximum
of eight available paths. Be aware of its possible movements along each of them, asking
if any squares it can reach would provide it
with an open line to the enemy king—and
whether any of those same squares also provide it with an open line to a loose enemy
piece. In practice you can disregard some
checks very rapidly, but as you are learning
about forks you are better off erring on the
side of being thorough.
Dg096: First observation: White’s rook is
unprotected. (So is his queen, but it’s a harder
target to go after.) Second observation: in
Qd4, Black’s queen has a safe check that attacks White's rook.
So there is the idea of the fork. But then you
also want to make sure White can't wriggle
out of it. His natural idea would be to try to
move the rook away and block the check all
in one move with Rf2. So suppose he does;
how do you figure out whether this reply
spoils your idea? Ask the cardinal question:
consider what your next check would be, and
with what consequences. Here it's Ra1, which
forces White's king to h2. His rook has been
left loose, so Black takes it: QxR.
Dg 095: White to move
Dg095: The example is as simple as the pattern gets. Again, you are looking for two
things: unprotected (“loose”) Black pieces,
and moves by White that check the Black
king. The idea is to combine those ingredients
to create a double attack. Black has one unprotected piece: the knight. White has one
way to check the king: Qd8. That move also
attacks, and collects, the knight after Black
spends a move relocating his king to h7.
Dg 097: White to move
Dg097: Look for unprotected Black pieces
and you find the rook at g5. Look for checks
White can give with his queen and you find
two: Qd8 and Qxg7 (be careful not to overlook a check just because the needed square is
occupied by an enemy piece). Qd8 is the winning move; it checks the king and also attacks, and wins, the rook.
Dg096: Black to move
Dg098: Black to move
Dg098: What White pieces are unprotected?
Both rooks. What checks does Black have?
Might as well be thorough about it: QxQ,
Qxe3, Qf3, Qg4, and Qxg2. Do any of those
also attack a loose rook? Yes, Qxg2; it wins
the rook on h1 after White moves his king.
This example illustrates the importance of
habitually noticing checks on squares like g2
where enemy men currently sit.
(b) Goal #2: be conscious at all times of any
checks you can give. Here there are two: Qd3
andQc2.
(c) Goal #3: look for any ways a check can be
combined with an attack on a loose piece.
Here Qc2+ attacks and wins the bishop.
Dg101: Black to move
Dg099: Black to move
Dg099: You are looking for unprotected enemy pieces and for checks, hoping to link
them for profit. Scan for unprotected White
pieces and you find the knight (as well as the
queen, but again the knight makes a more
feasible target for a fork). Now look for
checks, and in particular for a match—a
check that also attacks the loose knight. Qf5+
or Qf1+ work (it’s important to see both,
since they may have different side consequences), attacking both knight and king, and
winning the former after the latter moves.
Dg101: Search carefully for loose pieces and
checks. White has one piece that is unprotected: the rook at a2. Black has three checks:
Qe8, Qe6, and Qe4. You can match a check
with an attack on the rook with Qe6+; and e6
is unprotected. Black wins the rook.
Dg102: Black to move
Dg100: White to move
Dg100:
(a) Goal #1: be aware of loose pieces on the
board at all times. The Black bishop at c6 fits
that description.
Dg102: Does White have any loose pieces?
Yes, the rook on d7. How many checks does
Black have? Three: Qe2, Qd1, and Qb5 (examine the queen’s movements on every axis
open to it—vertical, horizontal, and diagonal).
You ask whether the queen can attack the
rook from any of those squares, and see that it
can do it from d1 or from b5; but of course at
d1 the queen is unsafe, as it gets taken by the
rook. So Qb5+ is the winning move.
cially on an open board like this, whether
your opponent might be able to move his
loose piece out of danger and block the check
at the same time. Here White can do this with
Rh2. Does this scotch the idea for Black?
Dg103: White to move
Dg103: Black’s rook is unprotected and so
makes a fine target. Now you look for queen
checks available to White and find many on
this open board: Qd7, Qb7, Qb4, Qg5, Qc5,
Qe8, Qe5, and Qe2. But we are only interested in checks that also attack the Black
rook, and from a square that the rook cannot
attack. Qe2+ works—a study in the importance of considering backward moves as well
as the more obvious attacking moves that
push your pieces toward your opponent’s end
of the board.
Dg104: White to move
Dg104: Now a defensive study. White is
about to play BxN, which looks safe. But
consider the board as it would appear after the
capture. Ask what White pieces would be left
loose and you find the bishop then at b3. Ask
what checks would Black have, and especially
any that also would attack the bishop, and you
find Qb6+, which would win back the lost
piece after White moves his king.
Dg105: Look for checks; look for loose enemy pieces; put them together with Qh7—a
queen fork that appears on its face to win the
rook at c2. But always you have to ask, espe-
Dg105: Black to move
No; he persists in looking for his next check
and sees that Qb1 would then be mate. (Notice how cramped the White king’s position
becomes once the rook is on top of it; the
Black king at f3 is doing valuable work cutting off flight squares. These cues suggest the
importance of looking carefully at the effect
of any attacks you can make against Black’s
king.) So if White is alert, Black’s queen fork
wins the rook on c2 after all. If White isn’t
alert, he is mated. It’s a study in the value of
always examining your next check and its
consequences, even if the result of the first
one you saw was disappointing.
2.2.3. Using the Side of the Board During
the Opening.
Before examining some complications, let's
focus for a moment on one type of simple
queen fork that often arises early in a game:
the move of a queen from its original position
to the side of the board, where it may be able
to check the enemy king and also attack a
loose piece in the center. First we will look at
a couple of elementary examples to illustrate
the idea; then we will examine what the pattern can look like from a defensive standpoint
just before it arises.
Dg106: White to move
Dg107: Black to move
Dg106: In this first example, examine the
protection each Black piece enjoys and notice
that both rooks and (above all) the knight are
unguar-ded. Now ask what checks White’s
queen can administer and what else it can do
at the same time. You see that it can attack
Black's king by moving to a4, and that from
there it also attacks and wins the loose knight.
Study the pattern of open squares on the d and
c files here so that it is visually familiar to
you.
This is a classic pattern. A queen from its
starting position on the board often can check
the enemy king by jumping to the a-file or the
h-file, so long as the pawns blocking its
path—first its path to the side of the board,
and then its path to the enemy king—have
been moved out of the way. The key squares
to monitor are the c2/d7 pair and the e2/f7
pair for White; if either of those sets of
squares have been evacuated by their pawns,
the White queen may be able to check the
enemy king with one move and simultaneously attack a loose piece near the center.
Likewise the c7/d2 and e7/f2 pairs from
Black’s standpoint. When you see these pairs
of squares open up early while the enemy
king still is in the center, think hard about any
moves or exchanges that would leave a piece
unprotected in the middle of the board, or that
would leave a piece there attacked once and
protected once.
Dg107: Now the same idea from Black's side.
White has just made a capture that left his
knight loose in the middle of the board; he
thought the e5 square looked safe. But with
the d2 and c7 pawns both moved, see how
Black’s queen can check the White king and
attack (and win) the loose knight with one
move: Qa5+.
Generally speaking, the most striking early
tipoff that a move like this may be possible is
the movement of pawns on the c or f files.
Movement of the d and e pawns early in the
game is common; early movement of the c or
f pawns is a little less standard, and so should
jump out at you as creating the possibility of
moves like we see here.
Dg108: Black to move
Dg108: Here is a study in caution. White just
played the pawn capture d5xe6. Black must
respond; but how? The important thing to
notice is that White’s c and e pawns have
moved, creating open diagonals for his queen.
If Black’s f-pawn moves (to play f7xe6), the
White queen suddenly will be able to check
the Black king by moving to h5; if Black
plays Bxe6, White’s queen can check with
Qa4. The reason this matters, of course, is that
Black has left a piece loose on a5. So Black
mustn’t play f7xe6—as he did here, losing the
knight to the queen fork Qh5+. He is better
off using his d7 bishop to take the pawn on
e6; for then if White tries a queen fork on the
other side—Qa4+—Black can both move his
knight to safety and block the check with
Nc6. This is a common way that a goodlooking queen fork can be spoiled: the forked
piece moves to block the check, and suddenly
both threats are gone.
Another way to see this, naturally, would be
to start by keeping tabs on Black’s loose
pieces. Here he has a loose knight on the fifth
rank. Loose pieces on the middle ranks often
are vulnerable to double attacks of this type
by the queen, especially early in the game; in
view of this vulnerability, Black should think
carefully before opening any fresh lines to his
own king. White can treat the situation as an
opportunity; in effect Black's f7 is subtly
pinned in place, since if it steps forward
White has a queen fork.
Incidentally, f7xe6 also would be a weak
move for Black on strategic grounds. It weakens the pawn cover on his kingside, where he
might want to castle; and it creates a little
pawn island—an “isolated” pawn with no
fellow pawns on the files to either side of it—
that will have to be protected by a Black piece
from now on.
Dg109: Another study in due care. Black has
just played Nf6, resulting in a common position four moves into the open Sicilian defense. White’s e-pawn now is under attack
and is not protected. White has to do something; but what?
Dg109: White to move
One possibility is to push the pawn to e5. This
might seem attractive because it advances
White’s center and attacks Black’s knight,
forcing it to move. But first you need to notice that White’s d-pawn and Black’s c-pawn
have been moved—a normal state of affairs in
this opening. This means that Black’s queen
is one move away from being able to both
check the White king and attack any White
pieces on the fifth rank, which White must
therefore regard as a zone of great danger.
Playing e4-e5 thus is a mistake because it
leaves the pawn loose; it will be taken a move
later by the double attack Qa5+. White should
instead protect the pawn with Nc3.
Dg110: White to move
Dg110: More exercise in avoiding trouble.
It’s early. White has moved a pawn and one
of his bishops; Black has just made c7-c6 his
second move. What should White play? The
important thing to notice is that now the
White d-pawn and Black c-pawn both have
been moved. With Qa5+ the Black queen can
check the White king and also attack anything
on the fifth rank, such as White’s loose
bishop. White should protect the bishop or
block the queen’s path to the king with a
move like c2-c3. If White instead plays e2-e3
here, naturally Black replies Qa5+, winning a
piece.
Notice, by the way, that in the position as
diagrammed Black would not quite be ready
to win anything with Qa5; the move is a
queen fork, but White has a solid response in
Bd2 or Qd2, either of which both blocks the
check from a5 and gives protection to the
bishop. It is a regular part of considering a
fork to ask whether both prongs of it can be
blunted by a single move like one of these.
But if White plays his pawn to e3 those de-
fensive moves no longer work because he has
obstructed the path from his bishop to the d2
square.
Study the visual appearance of the Black
queen’s path here—the elbow-like pattern of
open black squares leading from its position
to the White king. It's something you never
want to overlook. You also can treat this as a
case study in the danger of leaving pieces on
the board that have no protection but that
seem safe because nothing is attacking them.
They are prey to forks. The sight of White's
bishop sitting out on g5 like this, bereft of
protection, should make you edgy.
Dg112: A last example of the defensive implications of our current theme. Black just
played c5xd4. If White plays Nxd4, the natural recapture, his knight and bishop are poised
to be forked by Black’s e-pawn. (We will
study this pattern closely in the chapter on
pawn forks.) Perhaps White shouldn’t worry
about this, because if Black plays e7-e5,
White can just play Bxe5. Or can he? Again,
White should not play in the middle of this
board without noting that White’s d-pawn and
Black’s c-pawn both have been moved. That
means anything White leaves on the fifth rank
at the end of an exchange is likely to get taken
in a fork by Black’s queen. Bxe5 indeed
would have that effect, losing the bishop
when Black plays Qa5+. So White would
have no good answer to the pawn fork e7-e5,
and dares not play Nxd4 in the first place.
Dg111: White to move
Dg111: Black has just played e7-e5. The
pawn he has left on e5 has no protection, so
White appears to be able to take it for free
with his knight. Again, however, notice that
the move would leave the knight loose. Notice also that the Black queen can give check
with Qa5 and at the same time can attack the
fifth rank. So White must not leave any pieces
loose there; Nxe5 would lose the knight to
Black's queen fork a move later.
Dg112: White to move
Dg113: Black to move
Dg113: Play began 1. e4, e5; 2. Qh5. Now
what should Black do? White’s last move is
not quite comparable to the forking moves the
queen made in the previous examples, because here the queen does not have an open
line from the h-file to the enemy king. But
danger lurks nevertheless. One way for Black
to chase away the queen is to play a pawn to
g6. The move fails to protect the e5 pawn and
is poor for that reason alone; but more importantly, ask the question White will be asking
himself after that move: what checks will he
have? Qxe5+—which also attacks and wins
the unprotected rook on h8, the line to which
would have been opened by Black’s last
move. A simple move to protect the pawn on
e5, such as d6 or Nc6, was indicated for
Black.
Black’s bad second move is unlikely to occur
in any actual game you play (nor is White's
second move, Qh5); this position is given just
to illustrate the damage a queen can do after it
has moved to the side of the board and then is
given a chance to move to the center. We will
see a more involved example of this pattern
later in the chapter.
2.2.4. Making the Forking Square Available.
Now that you are familiar with simple queen
forks, consider a first way they can become
complicated: the square you need—the forking square—might be protected. “Protected”
does not mean there is an enemy piece on the
square, of course; it means there is an enemy
piece attacking the square—perhaps defending a piece that sits on it, or else just protecting it while it is empty. In either case, here
just as in the chapter on knight forks we will
see that an exchange often eliminates the
problem. Perhaps the defender itself can be
captured; perhaps the piece sitting on the
square can be captured, so that when its defender recaptures the square is left unprotected (with its former guardian now sitting
on it); or perhaps the defender can be lured
away by capturing another piece it protects or
making a threat (e.g., a check) that requires
the guardian’s services elsewhere. Since the
basic theme is familiar from the chapter on
knight forks, we will look more briefly at examples of how it works here.
Dg114: Examine the position using the approach already established: look for ways to
combine a check with an attack on an unguarded enemy piece. Here you see that Qd5
gives check and also threatens the loose
knight on a5. But before you make the move
you also have to ask whether—and how many
times—the needed square is protected. In this
case it's guarded by the knight on f6. So: do
you have any pieces attacking the knight?
Yes, the bishop on g5. The idea behind the
resulting sequence is familiar from the chapter on knight forks: 1. BxN, QxB; 2. Qd5+,
and White wins the knight.
Dg115: White to move
Dg115: Black has one loose piece: the rook at
h7. White has one check with the queen: Qg8,
which also attacks the rook. It all looks fine
except that Black guards g8 with his knight.
So press forward with the next question: Does
White have any pieces attacking the knight?
Yes, the bishop at c5 and the knight at f5.
(The two attackers are important; do you see
why?) Thus 1. BxN (or NxN), and after
Black's recapture, g8 is available for the
White queen to administer the fork.
The answer to the question about the two attackers is that the double attack would be
foiled if Black could recapture on e7 with his
king; for then White no longer would be able
to give check with Qg8. But Black's king can't
make the recapture because whichever piece
White uses to capture on that square is still
protected by the piece he didn't use.
Dg114: White to move
Dg116: Notice the checks Black has with his
queen: Qd1, Qe2, and Qxe5 (never overlook a
check just because the needed square already
is occupied by the enemy). Consider whether
any of those moves also attacks anything else
and see that Qxe5+ aims the queen at the
loose rook on a1. The only hitch is that the e5
bishop (the e5 square, really) is protected by a
pawn. Black has nothing he can use to capture
the pawn, so ask another question: if the
bishop is taken by another piece and White
recaptures with the pawn, will e5 become
available?
draw the knight onto e6 so that the queen can
capture it and execute the double attack at the
same time. Is there any other piece the knight
protects that could be taken? No. Well, when
in doubt, play with other checks you can give
and their consequences. Consider Rg5+. Notice that White’s queen greatly constrains the
ability of the Black king to flee such an attack; indeed, the king cannot be moved at all.
Black’s only option is Ng6, interposing his
knight between the rook and king. With the
knight thus budged from f8, the way is clear
for White to play Qe6+ and win the bishop.
It's hard to overstate the value of looking at
checks and their consequences.
Dg116: Black to move
Yes, it will. Black thus plays 1. …RxB+, 2.
f4xR, Qxe5+, and then takes the rook, gaining
a piece and a pawn.
In the previous two positions we captured the
guardian of the needed square; here we capture the occupant of the square and invite recapture. The result in either case is the loosening of the square.
Dg117: White to move
Dg117: This one is harder. A scan for loose
pieces turns up the bishop on e2. White’s
queen can attack the bishop and check the
Black king by moving to e6; but e6 is protected by the knight at f8. White can’t capture
the knight, and there is no way for him to
Dg118: White to move
Dg118: Search for loose Black pieces. Only
the rook at a8 is unguarded—but there is an
open diagonal leading to it, making it a promising target. To exploit the situation you need
a way to attack the rook while also attacking
something else. The queen is the classic tool
for such a purpose, but here White's queen has
no checks to give. So move to another question: what mating threats does White have? A
simple way to search for mating threats is by
looking for pieces that attack squares next to
the enemy king; adding an attack by the
queen against such a square often creates a
mating threat that is as good as a check for
purposes of creating a fork. Here White’s d3
bishop attacks h7, next to Black's king.
White’s queen also can attack h7 by moving
to e4 or h5; so the queen’s move to either
square threatens Black with mate on the next
move. Of these two moves the interesting one
is Qe4, since it also attacks the loose rook.
Naturally you first ask whether the needed
square is available and find it is not: e4 is
guarded by Black’s knight.
2.2.5. Loosening the Target by Exchanging
It.
The procedures for handling this sort of problem are well-known to us now. We start by
asking whether the knight can be eliminated
with an exchange, and it can; 1. BxN, BxB
leaves e4 unprotected, after which 2. Qe4
wins the rook after Black spends a move
fending off the mate threat.
The studies so far in this chapter all have involved spotting a double attack waiting to be
executed—and perhaps then perfecting it by
loosening the forking square to make it available for the queen. Now we move to another
pattern: the target piece—that is, the piece
you intend to capture—does not start out
loose; you have to loosen it with an exchange.
Or it has to be moved onto a square where it
is loose and can be forked. The thought process typically starts with the observation that
your queen can check the enemy king; then,
seeing no loose pieces it can attack at the
same time, you get to work to create one.
We will study this way of creating and using
mate threats in more detail soon.
Dg119: White to move
Dg119: The key to this position is that White
has a check he can give with his queen by
moving it to e5—and from there the queen
also is lined up against a pair of Black pieces
on the fifth rank. Obviously Qe5+ isn't yet
feasible because Black’s rook protects the
square, but the potential for a fork should attract your attention and cause you to focus on
getting rid of the rook. There are standard
tools available for the purpose. A first recourse is to capture the nettlesome piece, but
White can't; a second is to take something the
rook protects, but this, too, is impossible.
There remains a third option, however:
threaten the rook with something less valuable than itself so that it has to be moved
rather than just protected. A pawn is best for
such purposes, so White plays the simple g3g4. If the rook moves to safety, White has the
queen fork Qe5+, winning a piece.
Dg120: White to move
Dg120: We’ll start with a simple method.
Look for checks your queen can give that also
attack another enemy piece. If the piece is
protected, ask whether you can capture it with
one of your other men; perhaps when its replacement recaptures it will be left unprotected and will be a suitable target for a fork.
Applying this approach to the position on the
left, we find two queen checks to consider:
Qe4 and Qf5. Ask whether you can attack
anything else with those moves and you see
that Qf5 threatens the Black bishop at d7. The
bishop is an unsuitable target; it can hit back,
and anyway it is protected. So ask whether
White can take the bishop with another piece,
forcing an exchange that will replace the
bishop with a better target. He can: 1. RxB,
NxR leaves a loose piece where there used to
be a protected one. Now Qf5+ wins the
knight, netting two minor pieces for a rook.
Another way to see this would be to start by
examining captures you can make and their
consequences. One capture for White to consider is RxB. You see that it provokes NxR.
The critical step is to think about how the
board would look after this exchange, asking
what would then be possible. Note that the
knight would be left loose and so would make
a great target for a double attack. Might it be
attacked with check? Yes, with Qf5+.
Dg122: White has one queen check: Qxg6.
This also attacks the bishop on f5; but the
bishop is protected, and can capture on g6
anyway. So the next question is whether
White has any other pieces attacking the
bishop that he might use to force an exchange
which will leave g6 occupied by a more suitable target. The answer is 1. RxB, RxR. Now
2. Qxg6+ takes the rook left on f5 and so nets
a piece and a pawn. (Black was required to
use his rook to recapture, of course, because
the g6 pawn was pinned.)
Dg121: White to move
Dg121: What checks can White give with his
queen? Diagonal moves won't work because
the queen is on a dark square and the king is
on a light one. But White does have a
check—his only one on the board—in Qxf5.
So now you ask whether the move also would
attack anything else and notice that the queen
would be pointed at the bishop on d7. The
bishop isn't loose, but it's attacked once and
protected once. Thus consider a preliminary
exchange that might leave behind a loose
piece: if White plays 1. RxB, RxR, the result
is a loose Black rook on d7. Now Qxf5+ forks
the rook and nets a piece and a pawn.
Dg123: White to move
Dg123: What checks can White give with his
queen? Four: Qa4, Qb5, Qe6, and Qxf7. Two
of those—Qa4 and Qb5—also attack the
black bishop. The bishop is protected, so
naturally you look for an exchange that would
leave a loose piece on a6. White can go after
the bishop with his rook; after 1. RxB, RxR,
White has a good loose target to pair with his
check of the king. He plays Qb5+ and takes
the rook, again netting a piece.
Dg124: White to move
Dg122: White to move
Dg124: Here's a similar position. What checks
can White give with his queen? One: Qa4.
Does the move attack anything else? Yes, the
bishop on a6, but the target is protected—
until White takes it with his rook, causing a
recapture by Black’s knight: 1. RxB, NxR.
Now Qa4+ safely takes the knight.
double attack—is guarded by both the queen
and the b6 knight.
2.2.6. Loosening the Target by Disabling
its Guards.
Now let's consider other ways of loosening a
piece that you hope to fork: capturing its
guard or luring the guard away with an attack
on something else it protects.
Dg126: White to move
Dg125: White to move
Dg125: White has two queen checks in the
example to the left: Qa3 and Qb4. Both
moves also attack the bishop on a5, but the
bishop is guarded by the knight at c6. There
are two natural ways to deal with this: capture
the bishop with another piece, so that the
knight recaptures and is then a good target
(our previous theme); or take out the knight
directly. White has nothing attacking the
bishop, so an exchange of the sort considered
in the previous section is not possible. But
does White have anything attacking the
guard? Yes: 1. BxN, d7xB leaves the Black
bishop loose; Qa3+ then takes it.
But pick one of those problems and play with
it. The rook can’t be exchanged for a loose
target as in the previous section, but ask
whether either of its guardians might be taken
and with what consequences. Indeed White’s
rook attacks the Black knight, so walk
through the capture, recapture, and resulting
position in your mind’s eye. If 1. RxN, then 1.
… QxR—and now the rook at d7 is loose and
the e8 square is left loose as well. White takes
the rook with the queen fork Qe8+, winning a
piece.
Notice how a single capture and recapture can
have a terrific impact on the board, here creating a double attack where none had seemed
possible. It shows why looking at exchanges
is another good place to start your interrogation of a position. Here, for example, you
might have begun with a look not at Qe8+ but
at RxN. The important point then is to follow
up by imagining the board as it would look
aftewards and re-asking routine questions:
e.g., might a check then be combined with an
attack on loose piece?
P.S. The White king was inadvertently omitted from this one; until the diagram gets fixed,
imagine it on h2!
Dg126: (Here is another of those occasional
diagrams in need of a repair; until the fix is
made, pardon the omission of the White
king!) White has a queen check to explore in
Qe8. It might prematurely be dismissed as
impractical, since the Black queen guards e8
and the rook at d7—the possible target of the
Dg127: What checks can White give with his
queen? Only Qg4. Having seen this, dig for
some way to attack a loose Black piece at the
same time.
can’t allow this. And since he is unable to
move his king, he has no choice but to take
out the pawn with Nxh6. White asks what
would then be possible. Returning to first
principles, he looks for any checks he would
be able to give and any forks he might inflict
in the process. This leads to Qf6+, winning
the loose knight.
Dg127: White to move
The cluster of pieces at c8, d7, and e7 looks
promising, but as yet contains no suitable
targets; so ask what the effects of an exchange
would be. Look in particular for any trouble
you can start that will leave a Black piece
loose at the end of it. 1. RxR, QxR leaves the
c8 rook unprotected, and thus makes it a good
target that White can reach from g4. 2. Qg4+
wins the rook after Black moves his king.
Soon we will look more closely at uses of
mating threats to create queen forks, but the
basic principle is clear enough: a mate threat
that doesn't at all work to create mate may
work wonderfuly in other ways—viz., to create a loose piece. In this case the point of the
mate threat created with h5-h6 had nothing to
do with actually achieving mate. The point
was to force Black to rearrange his pieces in a
way that would lead to new tactical shots. Try
thinking about mate threats in this way: as a
means to an end other than mate.
2.2.7. Moving the Enemy King into Position.
Dg128: White to move
Dg128: And now a last related idea. We have
seen that a first principle of tactical play is the
importance of inspecting checks you can give
and your opponent's responses. A second and
related principle is the importance of experimenting with any mating threats you can create—most typically by directing a second
piece at a square next to the enemy king that
you already attack once. Here is a simple example. White’s queen hovers near the Black
king. The situation is tense because White’s
knight is pinned, but White does have one
obvious offensive possibility: h5-h6, where
his pawn then is positioned to provide cover
for Qg7# next move (it follows the formula:
the pawn adds an attack against a square already attacked once by White's queen). Black
Now consider a scenario opposite to the one
we have been studying: you see a loose enemy piece you can attack, but not the other
ingredient of a classic queen fork: a check
you can give at the same time. You need to
make the king move someplace where it can
be attacked simultaneously with the loose
piece. The most natural way to do this is with
a preliminary check from a different piece or
perhaps from the queen itself. The check
forces the king to move, and once it reaches
its new square a fork may follow. Another
way to move the king is by initiating an exchange, rather than a check, that draws the
king onto a square where it can then be attacked—or pushed around some more. The
practical point: if you need to move the king,
ask what checks you have and what the king
protects that you might be able to capture; if
the answers to those questions help move the
king but not far enough, then ask them again.
Dg129: Black to move
Dg130: White to move
Dg129: In this first example, White’s rook is
loose; that is a starting point for analysis because it gives you a target to focus on. Ideally
Black would like a move that attacks the rook
and gives check at the same time. Presently it
can't be done, so look for any checks that
might force the White king into a position
where it could be attacked along with the
rook. It turns out that Black has just one such
check to examine: Rd1. White is required to
answer with Kh2. Now reassess the resulting
board, again asking whether Black can attack
the king and the loose rook at the same time.
This time you find Qb8+, winning the rook.
Dg130: Black’s rook is loose, but there is no
way for White’s queen to attack it and give
check at the same time. So look at the checks
White can give and consider their consequences. There are five such possibilities:
Qa8, Qe8, Qh7, Qh4, and Qh1. A couple of
them—Qa8 and Qh7—can be dismissed
without any real thought. But then there are
the others: (a) Qe8+ forces the king to h7; this
almost works because it then allows Qe7+,
attacking king and rook. But of course Black
replies RxQ. (b) Qh4+ forces Kg8 but leaves
White with no good follow-up; from h4 there
is no way to attack king and rook simultaneously. (c) Qh1+ also forces Kg8. But this time
White does then have a move that attacks
king and rook at the same time: Qg1+, winning the rook.
The other route to the solution is to look first
at Rd1. When your rook has a clear path to
the enemy king's rank, it's natural to consider
moving it there and to ask what the reply
would be. Here you see that White's king escapes to h2. The crucial thing is to keep pressing then, asking what your next checks might
be and whether any of them can be turned into
forks.
This position is a nice study either way you
look at it because the idea of a fork does not
particularly suggest itself at the outset; it is
not a case where there are visual clues indicating that the fate of White's king and rook
are linked. Producing a crushing, gamewinning fork in two moves thus might seem
magical to the uninitiated. But the magic is
the residue of method.
Dg131: White to move
Dg131: Black’s bishop is loose, so White’s
energies turn to ways it might be attacked
while also giving check. It can't be done from
the current position on the board; White’s
only check with the queen, 1. Qc8, doesn’t
attack the bishop. But it does push the king to
h7—and then might a double attack be possible? Keep your eye on the loose bishop,
which you are working to capture; and examine every check that would be available after
the king moves, looking for a double attack.
2. Qf5+ wins the bishop.
Notice the importance of not rushing off to
examine checks with other pieces, such as
White’s knight, in order to help arrange a
queen fork; sometimes the queen can do all
the work by itself, as it does here. (With
Black’s queen poised to give check, White
wouldn’t want to go forward with this sequence without making sure his own king will
be safe at the end of it; the fork will cause
White's queen to be taken far away from its
king and leave it out of position to supply
defense. But White would have a decent reply
to Black's Qg1, Qe1, or Qc1, so the coast is
clear for the fork.)
Dg133: White to move
Dg133: It all starts with seeing a loose piece.
Here Black has left his rook loose, so it's a
target and the focus of operations. White can
attack it with his queen but can’t give check at
the same time, and the check that is available
to the queen—Qe8—won’t change that. Yet
the fork seems so close: Qd3 attacks the rook
and would attack the king if only it were on
h7. Look for checks by other White pieces
that might push the king around, and you find
just one: Rb8+, which forces the reply Kh7.
Qd3+ follows, of course, winning the rook.
Dg132: White to move
Dg132: Our drill used to be looking for
checks. Now it's looking for loose pieces. (In
practice you want to do both, of course.) Here
Black’s bishop is loose, so look for some way
to attack it and give check. The queen can’t
attack the bishop with any of its available
checks: Qf8, Qh8, Qe3, and Qxg6. But examine the consequences of those moves and you
find that Qh8+ forces Kg5. Remember the
goal: to attack the loose bishop and give
check. Would that be possible from the new
position on the board? Indeed: Qe5+ then
forks king and bishop and wins a piece. Ideally you want to see this in one visual motion.
Imagine checking the king with your queen
from h8, and see the king move to g5 in your
mind’s eye; then see it aligned with the
bishop, enabling you to play Qe5+.
Dg134: White to move
Dg134: Are any of Black’s pieces loose? Yes,
the rook. White’s queen can attack it from d4
(and also from d7, but that’s unsafe), but not
while giving check, and the checks Qc2, Qd3,
and Qh6 all lose the queen. So look for ways
to draw the Black king into harm’s way by
checking it with another piece. White’s rook
has a check in RxB. If Black replies KxR,
then reconsider White’s attack on the loose
rook—still the target. Now Qd4+ has become
a working fork that wins back a rook and
leaves White up a piece.
nerable position, and find 1. BxB+, KxB.
Now Qd4+ forks and wins the knight. Since
White's move gives check, Black never has
time to carry out the knight fork he had been
threatening.
Dg135: White to move
Dg135: Again Black has left a rook loose.
White’s queen has no way to attack it and
give check—yet; its two possible checks at a2
and d5 both are met by Black with QxQ. But
look for other checks on the board and see
that the White rook has two: Rd8 and Rxg7.
Examine each of them. 1. Rd8+ goes nowhere
decisive after 1. …RxR, 2. QxR+, Kf7. But
now ask what the board looks like after the
other possibility—1. Rxg7. Black replies
KxR. With the king moved, reexamine the
checks that would then be possible; see that
Qd7+ has been turned into a working fork that
wins the rook.
Dg136: White to move
Dg136: White is unhappy to see that Black
has hit him with a knight fork from e3. But
since the fork doesn't include a check,
White’s response isn't tightly forced. He can
think about taking the offensive rather than
attempting damage control. So ask one by
one: are any of Black’s pieces loose? Yes: the
knight at e3 that is inflicting the fork. This is
the target. White’s queen can attack it, but not
while giving check; the Black king is hidden
behind the bishop at g7. So look for other
checks that might force the king into a vul-
This problem illustrates the importance of not
panicking when threatened with a knight fork.
It also is a reminder of why knight forks
against two non-kings often are so much less
effective than knight forks that give check.
Here White doesn’t have to move his king,
and so has time to mount a fresh threat of his
own.
Dg137: White to move
Dg137: Look for loose Black pieces and you
find both the bishop at b4 and the bishop at
g4. White’s queen has no checks that can be
paired with attacks on either bishop, so he
looks to his other pieces to help. The goal is a
check that will draw the king out where it can
be attacked at the same time as one of the
bishops. The natural check to try first is one
using White’s bishop, since that also vacates
c4 and makes it available for the queen.
Hence 1. Bxf7+; and then if Black replies
KxB, White has 2. Qc4+. This attacks the
king and both Black bishops, winning one of
them and gaining a pawn.
Dg138: This position is almost the same as
the previous one but with an additional exchange required at the beginning: 1. Rxf7,
RxR; 2. BxR+, KxB; and now Qc4+. Study
this example to see how the same basic
thought process still leads to the solution: the
loose Black bishops are the targets;
Dg138: White to move
Dg140: White to move
if White’s queen can move to c4 and give
check, it will win a piece. Bxf7 is ineffective
here because of the rook on f8, so you keep
looking for more artillery you can bring to
bear and find that the exchange Rxf7, RxR
makes possible the bishop check and sacrifice
that in turn leads to the queen fork.
Dg140: Black has a loose bishop at c6.
White’s queen has one safe, plausible way to
attack it: Qc2. If the Black king could be
drawn onto g6, a fork of king and bishop
would be possible. White’s bishop can help
by taking the pawn at g6, giving check and
taking a piece that only Black’s king protects.
If Black replies KxB, the board is now arranged for a queen fork with Qc2+, gaining
White a pawn.
2.2.8. Clearing the Path to the Forking
Square.
Dg139: White to move
Dg139: Are any of Black’s pieces loose? Yes,
the rook at a8; so that's our target. White’s
queen has two ways to attack it: Qe4 and Qf3.
Neither move yet inflicts a check, but perhaps
the Black king can be drawn into position to
be forked on f7 or h7 with an initial check or
capture by another of White’s pieces. White
plays Rxf7. If Black replies KxR, then Qf3+
wins the a8 rook. This is a good example of
using a capture rather than a check to attract
the king onto a square where it can be attacked; White forces the king to move by taking something that only it protects.
Now we move to a slightly higher level of
difficulty. These are positions where there is a
square from which your queen might attack
the enemy king and a loose piece, but where
another piece or two blocks the way: blocking
the queen’s path to the forking square, or its
path from the forking square to one of the
targets. Once you see such a situation, the
methods for resolving it are straightforward
enough; but often it can be hard to see in the
first place.
Our first pattern consists of cases where the
queen's path to the forking square is blocked.
You discover this situation by looking for the
ingredients for a double attack and finding a
square from which it can be made; then you
consider whether the queen’s path to the
square can be cleared with a threat or exchange.
Dg141: White to move
Dg142: White to move
Dg141: In the position, start by looking for
the raw elements of a fork. Why, look: with
Qa8, White can fork Black's king and his a7
pawn. How splendid! Yet perhaps we can do
better. First, does Black have any loose
pieces? Yes, the rook at d7. Ideally you want
to check his king and attack the rook at the
same time. Are there squares from which the
queen could do that? Sure: e6 or e8 (in principle d5 and f7 would work, too, but the rook
protects those so they aren't worth worrying
about—and then there's c8, which is inaccessible). So if the Black bishop on e5 were out
of the way, White would have a good double
attack. Can the bishop be captured by something other than the queen? No, and anyway
after any capture Black would recapture with
a pawn on e5 and the White queen’s path still
would be blocked. You want the e-file
cleared, so instead try threatening the bishop
with a pawn that it will have to flee. White
thus plays f3-f4. If Black moves the bishop
out of the way to d6, Qe8+ wins the rook. (In
the alternative, of course, Black might choose
just to forfeit the bishop; his best reply to f3f4 is Qh5, allowing him to reply to f4xB with
f6xe5.)
Dg142: Again, start by looking for the ingredients of a double attack. Black has a loose
rook at a8: a good target if you can take advantage of it. So ask whether you can check
his king and attack the rook at the same time.
Well, you can't; but are there any squares
from which it could be done, whether or not
they now are within reach? Yes: in principle
c6 would work, though at present it's protected and the queen's path to it is blocked.
Look to see what stands in the way; ask what
methods you have for clearing the queen’s
path through—and especially what exchanges. The natural answer is 1. RxN, d7xR,
2. Qxc6+, recapturing the rook and winning a
piece and a pawn. Notice how the single blow
(RxN) takes care of both of White's problems
at once, getting his own rook out of the way
and forcing Black to replace the protected
occupant of c6 with a loose pawn.
The hard part here is seeing the potential for a
fork in the first place, since at the outset your
queen has no promising checks. The trick is to
go with the clues that are available: see the
loose piece, and realize there is a square from
which you could give check—i.e., a forking
square—on e8.
Dg143: Black to move
Dg143: The drill repeats. Start by looking for
the ingredients of a double attack and work
backwards. Does White have any loose
pieces? Yes, a bishop at b5 and knight at e5.
The question is whether Black can check
White's king and attack one of those targets at
the same time. The path from a5 to the king is
clear, and from a5 the queen also could attack
the bishop or knight (this is a classic pattern
in the opening; we studied it earlier in the
chapter). So you've found a forking square,
and now the question is how to get the queen
to a5. Black’s own pawn is in the way at c7.
Try to clear it in a threatening manner that
will require a response from White and give
him no time to defend against the coming
fork. The simple move c7-c6 attacks the
bishop, forcing it to move; wherever it goes,
Qa5+ then wins the loose knight.
Dg144: Black to move
Dg144: Strictly speaking White doesn’t have
any pieces that are loose, but his bishop at h6
is attacked once and protected only once, and
by another White piece (the queen) rather
than a pawn. In a sense that makes the bishop
as good as a loose piece: if Black can attack
the bishop and give check, the bishop will be
lost; it will be attacked twice and protected
just once, so BxB will result (White wouldn’t
be able to recapture with QxB, because then
Black would play QxQ). But all this assumes
Black can get his queen onto a square where it
can give check and attack the bishop at the
same time—viz., h4. Black’s own knight at f6
stands in the way. The trick is to vacate the
knight from the square in a way that forces a
time-consuming response from White; so look
for captures the knight can make. 1. …Nxe4
attacks White’s queen and can’t be ignored.
White responds with 2. f3xN or 2. NxN, NxN;
3. f3xN. Either way, Qh4+ then wins the
bishop and Black nets a pawn with the sequence.
Dg145: Black to move
Dg145: The analysis here sounds almost the
same as in the previous frame. Start by looking for the ingredients of a double attack and
work backwards. If you ask whether White
has any loose pieces, the answer again is “not
quite" — but the b2 rook is attacked once and
protected once, and by another White piece
(the queen) rather than a pawn. This means
the rook is underdefended; if Black can attack
the rook and give check, the rook will be lost.
But all this presupposes that Black can get his
queen onto a square where it can check
White's king and attack the b2 rook at the
same time—i.e., d4. Only Black’s own knight
already on d4 stands in the way. The trick is
to vacate the square in a threatening way that
requires a time-consuming response from
White; so you look for captures and threats
the knight can make. Nxf3+ forks White's
king and rook and requires the reply g2xN.
Qd4+ then wins the rook at b2 as described
above.
A general point to take away from this position and the previous one is that when you
examine your opponent’s pieces, you want to
note not just whether they’re protected but
how they’re protected and whether they also
are also under attack from other directions
already. It's worth studying these two cases
until it's clear that the targets (the rook on b2
here, and the bishop on h6 in the previous
position) are vulnerable to forks in the same
general way that loose enemy pieces would
be.
Dg146: Black to move
Dg147: White to move
Dg146: First, does White have any loose
pieces? Yes, the bishop at d3 (and also the
rook at a1, but it’s inaccessible for now). You
would like to check White’s king and attack
the bishop at the same time, so look for a
square from which the queen might do it. You
see that e3 fits the bill, and that the queen
could reach it directly if Black’s own pawn at
e5 weren’t in the way. So ask whether the e5
pawn can vacate its square in a hostile manner
that requires a time-consuming reply. Yes: 1.
…e5xd4; 2. exd4 (or cxd4), Qe3+ wins the
bishop. You likewise might have seen this by
imagining the consequences of pawn trades
available to you in the center. You see that the
first round of captures just described leaves
the queen with a clear path to a new check—
and fork—at e3.
Dg147: White is behind in material and needs
to make something happen. Step 1: Experiment with checks, including a brazen gesture
such as Rd7, which invites Black to play
BxR. Step 2: Consider the board as it would
look afterwards; ask what lines would have
been opened or closed as a result and what
new checks you might then have. Here
Black’s bishop would have evacuated the
sixth rank, permitting White to play the
check, and fork, Qf6+ (taking protection from
the pawn on e5). The fork doesn’t quite work
because Black’s rooks are connected and
guard one another. So persist and ask what
move Black would make in reply to Qf6+. His
king would be forced to e8. Then Qxh8+
works for White after all; it's made safe because the connection between Black’s rooks
has been broken by his king. More importantly, it’s a skewer that wins Black’s other
rook: Black has to move his king back to the
seventh rank, and now White has QxRa8—
and a won game. Notice how goading Black’s
bishop onto d7 removed d7 as a flight square
for Black’s king—and thus forced Black to
respond to 2. Qf6 with Ke8.
The likely payoff from seeing all this, of
course, is the gain of just a pawn; for if your
opponent sees the fork coming — and you
should assume he will—he will not recapture
after exd4.
By the way, it also might have occurred to
you to start with e5xf4 (instead of taking d4);
this likewise moves Black's pawn out of the
way. What's wrong with it? The trouble is that
this time White can reply Nxf4, and then his
knight suddenly protects the bishop on d3 that
you had counted on as a target: it's no longer
loose!
So you have a winning idea if Black responds
to 1. Rd7 with BxR. But what if he doesn’t?
Consider whether he has anything better. His
only alternative would be to move his king to
f8 or e8. Think about what your next check
would look like either way. If he plays Kf8,
you have QxRa8—mate. If he instead tries
Ke8, 2. QxRa8+ no longer works because
Black has KxR. That’s okay, though; instead
you play 2. QxBe6+, forcing Kf8; then 3.
Qf7#. So Black is required to play 1. …BxR
in the first place to avoid mate. (These trains
of thought are worth reinforcing until they are
clear.)
Stepping back and looking at the original position, observe the open diagonals leading to
Black’s rooks. See how they invite the idea of
a queen fork, especially with the king on a
center file and especially with a friendly pawn
in the center poised to protect your queen.
The basic forking possibility (Qf6) is a little
elusive at first because the rook on h8 doesn't
become loose, and thus doesn't become a
good target, until later. You might think like
this: if I could get my queen onto f6, it would
fork Black's king and rook, and the rook
would become loose if the king were forced
by the check to step back onto the eighth
rank. So if only I could get my queen over to
f6...)
The other lesson to take away is the value of
considering bold moves like Rd7+. The move
looks counterintuitive because it loses a rook
on the spot and you already are behind in material. But this won’t stop you from experimenting with the move so long as you remember that the frequent purpose of such
checks is just to force changes on the board
that make forks or other tactics possible. That
probably is the easiest way to see the solution
here: not by spotting the forking idea from the
outset, but by experimenting with checks you
can give and then with new checks that become possible after your opponent's replies.
This leads you to Rd7 as a first move and then
Qf6—at which point the fork comes into
view.
2.2.9. Clearing Paths to the Targets.
Now consider another variation on our theme:
a potential fork is frustrated by a piece lying
between the forking square and one of the
targets—the king or the loose piece. Again
much of our attention will be devoted to the
process of noticing such situations; once they
are found, standard tools—threats and exchanges—often can be used to resolve them.
The most important general skill here is the
ability to see “jump checks”: moves that
would give check if some piece (perhaps an
enemy piece, or perhaps one of your own)
weren’t in the way. These are important to see
generally, and they are especially important if
you have found a loose enemy piece. For then
you turn all your efforts to looking for a way
to attack the loose piece and give check at the
same time, and you don’t want to overlook a
check just because there is a piece that would
need to be gotten out of the way before it can
work. The best way to find checks like this is
to try just aiming pieces at the enemy king. If
pieces of your own are in the way, look for
time-consuming threats you can make by
moving them. If your opponent’s pieces are in
the way, try to force them off their squares
with threats or by taking pieces they protect.
Dg148: White to move
Dg148: In this first example, look first for any
loose enemy pieces. Here Black’s rook is
loose at d7. Can White’s queen attack it and
give check at the same time? No, not yet. But
if the queen moved to g4 it would be aimed at
both king and rook; thus only the Black pawn
at g7 prevents a successful fork. So ask
whether White can draw that pawn out of the
way by taking something it protects. The g7
pawn guards the bishop at f6, which White
can take with his rook. So 1. RxB, g7xR; 2.
Qg4+ gets the Black rook and wins a piece.
Dg149: Almost the same. This time it is
Black's turn to move, so first look for any
loose White pieces and find the rook at a2.
Now ask whether Black’s queen can attack it
and give check at the same time.
check the king and attack a loose piece elsewhere at the same time.
Dg149: Black to move
No, not yet; but if the queen moved to d5 is
would be aimed at both king and rook. Only
the White pawn at g2 prevents this from being
a successful fork. So ask whether that pawn
can be drawn out of the way by capturing
something it protects. It protects the knight at
h3, which Black can take with his rook. So 1.
. . . RxN; 2. g2xR, Qd5+ wins a piece.
Dg151: Black to move
Dg151: A search for checks for Black turns
up Qb1; a search for loose White pieces turns
up the bishop on b7. Qb1+ would indeed be a
winning queen fork if the pawn on b3 weren’t
in the way. So now the position becomes
easy: to move a pawn, take something it protects. Black plays RxN; White replies b3xR;
and Black then has Qb1+, taking the bishop
next move and netting two pieces for a rook.
Anytime you have long open lines available
to your queen, inspect them carefully for opportunities like this.
Dg150: White to move
Dg150: Are any Black pieces loose? Yes, the
knight at d7. Can White’s queen attack it and
deliver check at the same time? No, but Qg4
would aim the queen at both a loose piece and
the king; it would be a winning fork but for
the pawn at g7. White’s goal therefore is to
draw that pawn out of the way. Ask whether
the pawn is protecting anything that White
can attack, and you are led to 1. Bxh6; now if
1. ...g7xB, then 2. Qg4+ takes the knight,
gaining a pawn and wrecking the Black king’s
pawn cover.
These first three examples all are basically the
same, of course; they involve creating holes
in the king’s pawn cover so that the queen can
Dg152: Black to move
Dg152: It might look for all the world like
Black has nothing here; the lines to White’s
king appear cluttered and inaccessible. The
trick is to notice that White’s rook on a1 is
loose, and then that Black’s queen is one
move from being able to attack it with Qg7.
(The open long diagonal should be conspicuous.) The question is whether the attack on
the rook can be paired with a check to create a
fork. A line from g7 to White’s king would
need to be opened, so study the obstacles on
that line—the little cluster of White bishop
and Black pawn, with a White pawn on f5.
This cries out for a pawn capture that clears
both blockages out of the way: g6xf5—and
now White has to either move the bishop or
lose it. If he moves it, Black has Qg7+, winning the rook.
At first the g-file in this position looks impassible because of the two men that lie on it;
Black’s pawn capture is a very useful maneuver, worth a long look, as it creates an unexpected open line in a hurry.
Notice that this position is structurally similar
to the previous one. In each, you start by seeing that your queen is one move from being
able to attack either the enemy king or a loose
enemy piece (half a fork); and you see that the
queen also would be aimed at the other half of
the fork—whichever of those two pieces (the
king or the loose piece) it wouldn’t be attacking directly. The hindrance in both positions
was that one of the lines the queen needed
was blocked; the challenge both times was to
get rid of the blockader; the solution in each
case was to start with a capture of something
the blockader guards, forcing it to evacuate
the needed line and leave it open.
Dg153: Black’s queen has a check that must
be seen (queen checks always must at least be
seen!): Qb4. When you examine a queen
check you are looking in part for forking
ideas; the question is whether Qb4 attacks
anything else.
Not directly, no, but from b4 the queen is
aimed at the knight on h4, which is loose and
therefore a target. The problem is the White
pawn on f4. Can it be eliminated?
Best would be to take something the f4 pawn
protects, but that’s not going to work here; in
reply to Nxe5, White has QxN+. So toy with
more direct threats to see what they do. Thus
g6-g5 is natural to consider, and then you see
that it does more than threaten the White
pawn. It attacks the knight, too, which has no
safe place to flee—an occupational hazard of
a knight placed on the edge of the board. So
White is about to lose the knight unless he
takes the Black pawn that threatens it; yet if
he plays f4xg5 he loses the knight anyway to
Black’s queen fork Qb4+. (White also can
reply to Black’s initial pawn push with Qd4,
preparing Qxa4. Or White can play 2. Nxf5,
QxN. The material outcome is the same.)
There is a matter of move order to consider.
Black could start with Qb4+, forcing Kc1.
Then comes g6-g5, and again White must lose
the knight (in effect White’s f-pawn is now
pinned). Why not do it this way? Well, you
could. But now if White plays 2. Nxf5, Black
can’t recapture with his queen, for it is over
on b4. Instead Black has to recapture with his
e6 pawn, which in turn gives White a passed
pawn on e5 that he can push to e6, threatening
to promote it eventually and menacing
Black’s knight right away. Black can deal
with this (one possibility is Qe7, pinning the
pawn; another is Qc5, attacking White’s
queen), but starting with g6-g5 avoids these
complications.
Dg153: Black to move
Dg154: White to move
Dg154: Black has a loose rook at d7: a target.
White’s queen can attack it by moving to h3,
g4, or f5 (you attack rooks diagonally, and
bishops horizontally or vertically), but none
of these moves attacks anything else at the
same time; the path to the king is blocked by
the pawns in front of it. So consider what
other resources White can bring to bear—
what forcing moves, and with what results.
Experiment with the knight. It has an easy
fork with the check Nf6+; Black has to reply
g7xN, not only to avoid losing the rook but to
avoid being mated with Qxh7. But then a line
to the king has been opened; now Qg4+ attacks both king and rook, winning the exchange.
If you need to move an enemy pawn, whether
in front of its king or elsewhere, the most
common method is to take something it protects. But another technique to remember,
shown here, is to imagine sticking one of your
pieces en prise to the pawn and consider
whether it makes an interesting threat that
your opponent would feel obliged to extinguish, thus leaving you with an open line on
which to play a tactic. Or maybe he will decide that he can't afford to extinguish the
threat by making a capture because its side
effects are too severe (i.e., the queen fork)—
so instead he has to let you push your first
threat forward.
Dg155: White to move
Dg155: This is similar to the previous frame.
What Black pieces are loose? The knight at a5
and the rook at e2. It would be hard to fashion
a double attack against the knight, but the
rook, isolated deep in White’s territory and
near the White queen, is a perfect target. Is
there a square White’s queen can reach that
would enable it to attack Black’s king and
rook at the same time? If the queen were on
g4 it would be aimed at both targets. But its
path to the king would be blocked by the
pawn at g7, and of course the White knight
already occupies g4. What White needs is a
way for the knight to vacate g4 with a capture
or threat that requires Black to respond, and a
way to remove the pawn at g7. Nxf6 and Nh6
suggest themselves as ways to achieve both
objectives at once. Nxf6 doesn’t quite do it
because Black can reply QxN without moving
the g7 pawn. But Nh6+ forks queen and king
and so requires g7xN in response—after
which Qg4+ forks and takes the Black rook.
Dg156: White to move
Dg156: This position illustrates a very useful
principle. White has a queen aimed at h7. If
the queen had cover from another White piece
aimed at the same square, the result would be
a mating threat. A classic way to so aim a
second piece is by putting a bishop behind the
queen, as with 1. Bd3. There is then a standard way for Black to address such a threat:
he moves his g-pawn forward to g6, interrupting the queen’s path (and, in this case, threatening it to boot). But the point of the mate
threat wasn’t to mate. It was to force this disruption of the pawn cover in front of Black’s
king. When pawns step forward as Black’s gpawn does here, lines to the king often are
opened that can then be used for other tactical
purposes—such as forks. In this case notice
that Black has a loose bishop on d6; after the
little sequence just sketched White takes the
bishop with 2. Qf6+, Rg7 (interposing to
block the check); 3. QxB.
The pattern here is important to master: lining
up pieces against the enemy king’s position so
he is forced to move his pawns forward, then
exploiting the line he has opened with a fork
or other tactic.
Dg157: White to move
Dg157: See the loose rook on c8. See the exposed enemy king on h8. See that in one
move your own queen nearly can get into position to attack both targets with Qh4. Neither
part of the attack works yet; the point is just
to recognize this as a common general pattern
for a queen fork: the check against the exposed king down the side of the board, more
or less, and the accompanying diagonal attack
against a loose piece on the back rank. The
question is whether it can be made effective.
The pawn on h5 blocks the queen’s path on
the h-file; and the fork would have to be executed from g4 anyway in order to reach the
loose rook (or else the rook would have to be
moved). Well, getting the pawn out of the
way is no great challenge; just take what it
protects with 1. RxN. After h5xR, White can
work with checks and thus is in the driver’s
seat: 2. Qh4+, forcing Black’s king to the gfile; then 3. Qxg4+ (the fork) and 4. QxR.
So White gets a pawn, a knight, a rook for a
rook—if Black bites by recapturing after
White starts with RxN. He probably won’t,
which is fine; it leaves you with a piece. But
you also have to make sure that he doesn’t
have any killer threats of his own to play instead, and at this point the position becomes
more demanding than at first appears. Look at
any checks Black can play—and not just the
first check he can give, but strings of checks.
You need to satisfy yourself that you can escape whatever mess he can create. Imagine
him replying to RxN with Qa2+. This forces
your king to c2; then comes Black’s next
check, b4-b3+. This time your king escapes to
d1, and Black is out of checks. He can play
Qxb2, but since that’s not a check it leaves
you with a move to take your rook on g4 out
of the danger it still faces from the pawn on
h5.
That last point is important. The purpose of
looking at Black’s counterthreats is partly to
make sure you aren’t leaving yourself open to
a mating trap, but it’s also to make sure that
Black can’t play any forcing moves (checks,
mate threats, or captures) that will force you
to move your queen; for remember that while
all this action is going on in the near left corner of the board, your rook still has been left
en prise to Black’s pawn on h5. The only
thing preventing your rook from being taken
is the threat of the queen fork discussed in the
first paragraph. If Black can find a way to
distract your queen, your rook will be a goner
because Black will be able to take it without
consequence. But he can’t.
There is yet one more possibility you would
need to consider: Black can reply to Rxg4
with b4-b3. Again, you are looking for major
counterthreats Black could launch; this counts
as one of them because once the pawn has
moved to b3 it is ready to support mate by the
queen on a2. The pawn move also uncovers
the threat of QxQ next move. Black might be
thinking that this will force White to make the
preemptive strike 2. QxQ; then after Black
replies RxQ, the queens have been traded and
Black is ready to launch a mate threat of his
own with Rc8-a8, preparing Ra1#. But this
needn’t scare you, for White has another
move to play in the middle of that sequence.
If 2. QxQ, RxQ, then White goes with 3. Rc1h1. This pins the pawn on h5, so now White’s
rook at g4 is safe; more to the point, with
rooks on both the g and h-files White suddenly is ready to mate with Rxh5. Indeed,
Black cannot escape that result.
This position is worth a good look as a study
in anticipating your opponent's counterplay.
The reason the issue needs such close consideration here is that White's king is so exposed.
It's next to an open file on which Black has a
queen and rook, and its only flight square (c2)
is perilously close to being sealed off by
Black's b-pawn. This means that White has to
be very careful not to end up mated or otherwise burned by operations against his king's
position. It can happen at any time—even in
the middle of a tactical sequence White initiates elsewhere on the board.
loose piece on the fourth or fifth rank: the
queen at least would be aimed at both pieces,
with its path to the king blocked by the knight
at c6 and its path to the loose knight at e4
blocked by its own pawn at d4. So White
looks for ways to get rid of those blockages,
preferably at the same time. He starts by moving the obstruction he can control (his own d4
pawn), and using it to threaten the obstruction
controlled by the enemy. Thus d4-d5 attacks
the knight and forces it to move out of the
way. Now Qa4+ wins the knight at e4.
2.2.10. More Complicated Cases.
Now let's try some cases where there is more
than one complication to address. Here we
will start to see some problems where none of
the ingredients of a fork is obviously in place
at the beginning. This makes spotting the potential for a double attack harder. Instead of
looking for obvious tip-offs like loose pieces
the queen can attack or available checks, we
have to use a little more imagination; we look
for familiar visual patterns and we examine
checks, captures, and threats, searching for
signs that a fork is coming into view.
Dg158: White to move
Dg158: In the position pictured here, ask
whether Black has any loose pieces; you thus
are led to the knight at e4. White can’t attack
it and give check at the same time; indeed,
White has no checks at all. But if White’s
queen moved to a4 it would be close to executing the classic pattern seen at the beginning of the chapter, attacking the king and a
Dg159: Black to move
Dg159: White has a loose bishop at a4 (and
also two loose rooks which are less accessible). Is there a square from which Black's
queen would be aimed at both the bishop and
White's king? Hmm: h4 is an interesting start,
as from there the queen could give check and
would win the bishop if the e4 pawn weren’t
in the way—always assuming Black's queen
could get to h4 past the knight at f6. So Black
begins playing with ways to move both the
knight and the e4 pawn out of the way. The
natural method is to use the knight to attack
something the e4 pawn protects—like the d5
pawn. 1. … Nxd5; and then if White replies
e4xN, 2. ...Qh4+ wins the bishop.
You might just as well have seen this by playing with any captures you can make and asking what would be possible on the board as it
would look afterwards. This leads you to
Nxd5; after imagining the recapture e4xN,
you look for any new checks you would be
able to give and see the fork Qh4+.
after that exchange, and re-ask the important
questions: what checks now would be available, and what loose pieces? There are two
checks: Qd3 and Qc2. The interesting one is
Qd3, because it also attacks the Black bishop
on d5. The bishop is protected once, by
Black’s queen. But notice that now it would
be attacked twice, by the White queen and
rook. So Qd3+ wins the bishop after Black’s
king retreats.
Dg160: Black to move
Dg160: White has no loose pieces and
Black’s queen has no checks. But we examine
the consequences of every check as a matter
of course, and here Black has two of them:
NxB and Nf3. Nf3+ leads nowhere; White
plays g2xN. But what happens after NxB+?
White has to play QxN to recover his piece.
That little exchange would mean a significant
change in the position: Black’s knight and
White’s bishop both would be gone, and
White’s queen would be moved to e2. So rethink what would then be possible, noting any
lines that would have been opened, any
checks they would make possible, and any
White pieces that would have been left loose.
Black would be able to deliver a check with
Qd4, and at the same time attack White’s
newly loosened knight at c3: a perfect double
attack, winning a piece.
Dg161: White to move
Dg161: White has no queen checks and Black
has no loose pieces (except his queen, which
generally is not a suitable target for a queen
fork). Again, though, it is our practice to examine every check of any sort, and here
White has one: BxN, which leads to KxB. All
right; now examine the board as it would look
Dg162: White to move
Dg162: Here is a more challenging one. Black
has no loose pieces except his rooks, which
are tucked out of danger, and White has no
checks to give. The most likely way to see the
chance for a double attack here is to experiment with captures and their consequences.
There is just one possible capture here for
White: Nxd5, which more or less requires
Black to play c6xN. Then how would the
board look? What checks would then be
available? Answer: Qb5, which would attack
the bishop at b4 as well as the king. The
bishop is protected by Black's queen. But it
also would already be attacked once by the
White bishop at d2 (remember that when you
think of Nxd5, you imagine the knight gone
from its current square and see the open lines
that result). So the Black bishop would be as
good as loose: after Black moves his king in
response to Qb5+, White plays BxB and
Black dares not recapture.
The tricky part of this example is seeing the
potential for a double attack at all, since none
of the ingredients are visible at the start. But
even from the beginning you might notice a
basic pattern that is familiar by now: by moving to b5 the queen would be aimed at the
enemy king and would have Black’s bishop
just underneath it. Double attacks by the
queen often look like that. It doesn’t quite
work yet because the pawn at c6 blocks the
check and protects the needed square, and
because the bishop is protected once and not
yet attacked at all. Still, if you can see the
rough outlines of the familiar pattern, you can
then play with various forcing moves on the
board, like Nxd5, with a view to making the
queen fork effective.
here, but the geometry of Black’s position
should be provocative: QxR aims the queen at
Black’s king and also attacks the bishop at a5,
which would then (i.e., with the rook captured) be left loose. So see if you can move
your knight away from e6 with a threat. The
first type of threat to consider is a check.
Ng5+ is no good, as it gives Black a way to
both extinguish the check, save the rook, and
guard the targeted piece (the bishop on a5) in
one stroke: RxN.
You also might see the tactical idea here by
first observing that Nxd5 is a knight fork of
Black’s queen and bishop. Since the Black
bishop would also then be attacked once by
White’s bishop, the knight fork is a real threat
to Black and must be met with c6xN. This
then becomes a problem similar to the knight
forks we already studied where you imagine
playing the attack knowing that it will fail
when your knight gets taken; you ask what
would then be possible, and particularly what
checks you would have available. Here that
inspection would turn up a check by the
queen which also attacks the bishop for the
second time.
So now consider your other knight check: 1.
Nd8+, in reply to which Black has to either
take the knight with his queen or else move
his king. If he plays 1. …QxN, White has 2.
QxR, forking Black’s king and bishop and
winning a rook with the sequence. If Black
instead moves his king to f8 or g8 in reply to
the knight check, the results for him are even
worse. If the king goes to g8, it still gets
checked by QxR and mate follows soon for
White; if Black moves his king instead to f8,
then after QxR White can hold off on QxB
and instead move his own rook over to the hfile and prepare to drop it to h8, creating
havoc there (likely in the form of a skewer).
Dg163: White to move
Dg163: Here is another trickier position.
Black has two loose pieces: the rook and the
knight. The knight is out of reach, but what
about the rook? It almost seems that it could
be taken for free by the queen right now; then
Black plays QxN, attacking White’s queen,
and White has the exchange to show for his
trouble. But remain calm and see if you can
find something that is better still; don't assume the first good move you find is the best
one possible. The queen has no good checks
For now, though, it is enough to have seen the
power of the initial move Nd8. The challenge
of this problem, a bit like the challenge of the
previous one, is that White ends up taking a
piece that was not loose at the start by inflicting a check that also was not available at the
start. There are various ways you might have
spotted the idea: by recognizing the relationship between Black’s bishop and king, which
looks like a lot of other double attacks we
have seen; or by examining every check from
the outset (standard practice), finding Nd8+,
and seeing that afterwards QxR wins the
bishop; or by seeing that even if the bishop at
a5 is not loose, it would become loose as soon
as White played QxR with only the white
knight standing in the way of a good fork.
You look for ways the knight can evacuate its
square with check, and there you have it.
Dg164: Again we begin with no possible
checks for White and no loose Black pieces
(except the queen, which makes a bad target,
and bishop, against which nothing is possible).
more exposed to brutal tactical shots. It shows
how vulnerable a position can be when pieces
are protected by other pieces (rather than
pawns). A series of captures can force the
pieces all over the board and rather abruptly
leave one or two of them loose.
2.2.11. Using Mate Threats.
Dg164: White to move
Still, we do have some familiar geometry:
Qd5 aims the queen at both the Black king
and the rook at a8. Neither side of the attack
yet works, but the basic pattern is something
to keep in mind. The next step is to experiment with checks (White has none) and with
captures. The obvious spot for an exchange is
f5, where Black has a knight that White attacks. How many times is it attacked, and
how many times protected? Twice and twice.
So White imagines 1. NxN, BxN; 2. BxB,
RxB. Here is the key moment in the exercise:
imagine the board after those exchanges, and
re-ask what checks and loose pieces are available. Now Qd5 looks quite different. It’s a
check (the only one White then has), and the
rook at a8 would be loose and so would be
lost to the double attack. This problem is a
good illustration of two things: how much a
couple of exchanges that don’t seem to do
much by themselves can change the board,
and the importance of asking simple questions
about how the board will look after such exchanges are complete.
Take the opportunity of this position to think,
too, about the coordination of Black’s
pieces—and White’s disruption of it. In the
diagram Black’s pieces protect each other
nicely: his rooks guard each other, and his
bishop guards both knights and prevents
White from giving check on d5. With a couple of exchanges White ruins this coordination, suddenly leaving Black’s position much
Often the queen can attack a loose piece while
at the same time not checking the enemy king
but threatening mate. The enemy has to address the mating threat, so the loose piece is
lost just as it would be if the queen had delivered a check. To master this pattern it is important to understand a couple of principles
about mating threats and how to spot them. It
usually takes two pieces to create a mating
threat (or mate itself, of course). The threat of
a back rank mate is a prominent exception,
but for now just think about a classic set of
cases that does follow the pattern: your queen
is poised to attack a square next to the enemy
king that already is attacked by one of your
other pieces. At the same time your queen
attacks a loose piece. Your opponent has to
defuse the mate threat just as he would a
check, giving you a move to take down the
target.
Dg165:White to move
Dg165: The diagram illustrates the idea in
skeletal form. White has a bishop trained on
g7. His queen can threaten mate by jumping
to d4 or g4 because either move creates the
possibility of Qxg7#. Those mate threats will
make a fine anchor for a queen fork of any
loose pieces Black leaves within range of d4
or g4. The White X’s in the diagram thus indicate squares that White indirectly controls
because of the possible fork. (He already controls d7 with his queen; but imagine a pawn
on d2 and the control again becomes indirect.)
If Black leaves a loose piece on any of them
(or even a piece defended once but also attacked once by another White piece), White
may be able to win it by playing one of his
two mate threats, Qd4 or Qg4. Black will
have to respond to the mate threat by stepping
forward one of the pawns in front of his king
or in some other way, and then White will
win the target. In addition to taking Black
pieces left unguarded on those squares, White
also can carry out other operations there (exchanges, or putting his own pieces onto the
squares) with more confidence than might
appear to the untrained eye.
In real play the details of what White can do
here naturally will depend on which piece
Black has left on those vulnerable squares,
and of course on other pieces on the board
that will complicate the picture. The e6 square
is defended by a pawn; White wouldn’t be
able to use his queen to attack a bishop on a
diagonal; etc. Or suppose Black has a loose
bishop on b4 and White forks it with Qd4 or
Qg4. Black can save his piece by playing the
bishop back to f8; this both removes it from
danger and adds a defender to g7, thus defusing the mate threat. But these are details. The
important thing for now is just to realize that
in this humble-looking formation White has a
strong forking threat waiting to be unleashed,
that it isn't related to any check he can give,
and that it gives him a measure of control
over many squares that appear not to be under
attack.
Dg166: Inspect the position for loose pieces
and you find the Black knight on c6. White
has no safe way to check the king and attack
the knight at the same time (Qe8 would do it,
of course, but Black’s queen guards the
square). So next White looks for a way to
attack the knight while threatening mate.
Look for another White piece trained on a
square near the king. Here we have a classic
example that we will see several times in this
section: White’s bishop is attacking a square
next to the Black king (h7).
Dg166: White to move
If White’s queen moves in front of the bishop
on the same diagonal―i.e., to g6―then
White threatens mate on the next move:
Qh7#. So Black will have to address the threat
created by Qg6 by moving his king or bringing over his queen. Meanwhile Qg6 also attacks the loose knight. So after Black makes
one of the replies just described, White plays
QxN and takes the knight for free. Think of
this as a double attack on the knight and on
the h7 square.
Dg167: White to move
Dg167: Here is the same principle in slightly
different form. What Black pieces are loose?
The knight at a7 and bishop on d7. White
can’t give check and attack either piece at the
same time, so he asks whether he might attack
one of them while creating a mate threat. He
looks for pieces he has trained on squares
next to the king and sees that the bishop at a1
is aimed at h8. If White’s queen were to land
on h8 the game would be over. So White just
needs a square from which his queen can (a)
attack one of Black's loose pieces, and (b)
attack the h8 square. Qd4, winning the knight,
is the answer.
the same diagonal as the bishop—for example, by playing Qd4. But that doesn’t attack
the rook, and anyway d4 is protected by
White’s queen.
Dg168: White to move
Dg169: Black to move
Dg168: By now this one should be easy. Begin with the usual reconnaissance of enemy
pieces, looking for any that are unguarded or
underdefended; here it turns up the Black
knight on e3. White can’t give check and attack the knight at the same time, so he looks
for the makings of a mate threat: another
piece that attacks a square next to the king.
Once more his bishop answers the purpose; it
attacks g7. So he looks for ways his queen
might attack g7—the mating square—and the
loose Black knight. He finds Qd4, which wins
the piece.
As these first examples all show, a bishop
aimed at squares next to the enemy king can
be a valuable resource, as it creates a fertile
climate for double attacks with the queen. The
mating threats it supports may be simple to
defuse (here the simple pawn move f6 puts
out the fire for Black), but of course the purpose of the exercise never was to deliver
mate. It was to take loose enemy material.
Dg169: What White pieces are loose? The
rook at e1 (as well as the queen, but focus on
the rook for the usual reasons). Black has no
safe way to check the White king and attack
the rook at the same time, so he looks for a
mating threat. Here as before the bishop is the
answer: it attacks the b2 square (and pawn)
adjacent to the king. Black would mate if his
queen were to land on that square. If you followed the pattern of the previous problems,
you might look for a way to put the queen on
So Black looks for other squares his queen
could reach that would allow it to attack b2.
He finds Qb4, which threatens mate by Qxb2
and also threatens, and wins, the loose rook at
e1. The point: there is more than one way for
the queen to attack a mating square already
being hit by a bishop.
Dg170: White to move
Dg170: What Black pieces are loose? All of
them. White has no way to check the Black
king and attack any of those pieces at the
same time, so he looks for a mating threat; he
asks what other pieces he has attacking
squares near the king. This time his bishop
isn't helpful, but his knight is: it attacks g7. If
White’s queen were to land on that square, it
would be mate. So White looks to move his
queen to a square that would allow it to attack
g7 and also attack one of the loose Black
pieces. This leads to Qg5, which wins the
rook after Black makes a move to protect
against Qxg7#.
Dg171: White to move
Dg171: The only loose Black piece is the
bishop at a1. White can’t attack it and give
check at the same time, so he looks for mating
threats. His knight attacks f7 and h7; the attack on f7 is not powerful because Black protects the square with his rook as well as his
king, but h7 is only protected by Black’s king.
It follows that if White’s queen attacks h7 it
will threaten mate; the h7 square thus can be
treated a target in the same way a loose piece
or the king itself would be. So the question
for White is whether his queen can attack the
Black bishop and the h7 square at the same
time. It can; Qh1 threatens mate and so wins
the bishop. The long backward move of the
queen here is counterintuitive, and illustrates
the importance of methodically looking at
every way the queen can attack the vulnerable
points in the enemy position.
it in the usual way: look for loose enemy
pieces, checks, and mate threats. Black’s rook
is loose; follow this observation by looking
for a line the queen could use to attack it
while also being aimed at the king. Qh4 suggests itself. The move seems to fail because
the h6 pawn blocks your queen’s path to the
Black king’s position. But there is more than
one way for a fork to “work”; if the move
doesn’t give check, it still is enough if it
threatens mate. Examine the Black king’s
position and you see that White’s rook on the
open g-file has the king trapped on the side of
the board, and you see as well that the king
has no defenders. The conclusion: Qxh6
would be mate. So after White’s 1. Qh4,
Black doesn't dare move his rook; he has to
let it go. (Then again, no matter what Black
does, White can force mate soon enough
anyway. If Black plays 1. ...Kh7, for example,
then White plays QxR and can't be stopped
from playing Qg8#; Black can only delay the
move with useless gestures like Ne8 or
Qxb3+.)
Dg173: White to move
Dg172:White to move
Dg172: White’s best move obviously is the
free QxN. Or is it? This is a sterling example
of the importance of looking beyond a good
move to make sure there isn’t a better one. Do
Dg173: Black just played Bc5, adding a second attacker against f2 along with his knight;
maybe he meant to threaten a knight fork
there. To see why this was a mistake, look at
the board from White’s standpoint and ask
some standard questions: What mating threat
can White make? His bishop attacks f7, a
square next to the king and unprotected by
any piece other than the king; so White asks
whether his queen can add to the pressure
against that square and attack any loose Black
pieces at the same time. The answers are yes
and yes: if White plays Qd5, he now has a
mating threat; and he also attacks the loose
Black knight at e4. The knight can jump out
of the way and help guard f7 with Ng5, but
it's no escape. White already has g5 under
attack twice.
So after 1. Qd5 Black is obliged to lose material. He can play the check Bxf2+, so that his
bishop takes a pawn with it on the way down;
but then White calmly plays Ke2, and now
two of Black's pieces are under attack—his e4
knight by White’s queen, and his bishop by
White’s king. He will lose the knight next
move.
Lesson: leaving loose pieces around is dangerous business. Before putting his bishop on
c5, Black should have noticed (a) that he already had a loose piece in the middle of the
board, which always is cause for concern; and
(b) that White had a bishop attacking f7,
which is cause for additional concern since it
sets up a mating threat if White can aim his
queen at the square as well. Black would have
been better off making a move to address one
of those threats. Best is d7-d6, since then after
1. Qd5, Be6; 2. QxN, d6-d5 Black wins back
his piece with a pawn fork. (We will look at
pawn forks more closely in the later chapter
dedicated to them.)
what lines would then be open, and with what
tactical opportunities then available to you or
your opponent. One warning sign is that at the
end of the sequence White’s knight on e5,
while not attacked, would be loose. Another is
that Black’s bishop already attacks f2, adjacent to White’s king. Nothing except the king
protects that square (a common state of affairs
in the opening; this is why f2 and f7 often are
considered defensive weak spots early in a
game); so if Black’s queen were able to attack
f2 as well, White suddenly would be confronted with a mating threat. The threat could
be averted with various moves, but they
would take time, and meanwhile Black would
be able to take any loose piece his queen also
attacked. None of this looks like an immediate worry in the position diagrammed here,
but after the exchange of pawns and the recapture Nxe5 by White, the stage would be
set for Qd4, threatening mate at f2 and attacking, and winning, the then-loose knight on e5.
Dg175: Black to move
Dg174: White to move
Dg174: Let’s continue to look at the same
idea from a defensive standpoint. Here White
sees that Black’s pawn on e5 is defended once
(by the pawn on d6) and attacked twice (by
the pawn on f4 and the knight on f3). So he is
tempted to play 1. f4xe5; then if 1. …d6xe5,
2. Nxe5. But please don’t play an exchange
like this until you have imagined what the
board would look like afterwards—including
Dg175: Here's yet another example of how
the prospect of queen forks can figure into
defensive thinking. The two sides are fighting
for control of the center and especially of the
e4 square. Black sees that the White pawn
there is protected twice but that he attacks it
three times. In his mind’s eye he plays 1.
…Nxe4, 2. BxN, RxB; 3. RxR, QxR. But
before executing this sequence he must ask
the sorts of questions we have been discussing. First, would this liquidation of the position leave any open lines at the end that would
allow the enemy queen to attack the Black
king? Here Qg5 would be available to White,
and from there the queen would join the f5
knight in attacking g7—threatening mate.
Indeed, that move already is available. What
prevents it from working is the absence of a
second target: the queen would be aimed at
the rook on d8, but its path would be blocked
and the rook would be guarded. But after the
exchanges Black imagines on e5, these obstacles would be gone. Indeed, the resulting position would be one you saw about five
frames ago: it leaves a fork for White. So the
sequence Black imagines must not be played;
after it is complete it results in 4. Qg5, Kf8; 5.
QxR+, Qe8; 6. QxN.
This example shows how a few precautionary
questions, asked as a matter of course before
entering into a series of exchanges, can save a
lot of trouble at the end. You carefully imagine how the board would look after the series,
including any new open lines and loose
pieces; and you then ask the same questions
about that resulting position that you ask
about positions in front of you: would either
side have any loose pieces that could be attacked while giving check or threatening
mate? If this seems like a demanding position,
note again that the mate threat Qg5 is available to White from the beginning. Both sides
should be conscious of this. It means that if
White’s queen were able to attack anything
loose from g5 he would have a working fork,
so any sequences Black attempts have to be
inspected to make sure they don’t produce
that outcome. The moral: if your opponent is
a move away from being able to create a mate
threat, no matter how ineffectual, keep a careful eye on it as the potential basis of a fork.
Dg176: White to move
Dg176: Where is the idea this time? You have
a bishop trained on g7. One important effect
of such a resource is that you can create a
mate threat by adding an attack by the queen
against the same square, as with Qg3; so the
key question is whether you can make another
threat with that move at the same time. You
see that from g3 your queen would be aimed
at the rook on b8. The position thus has the
makings of a classic queen fork, but there are
a few problems in the way of its execution.
The rook is guarded by the knight on d7; the
queen's path to the rook would be blocked by
White's own rook on f4; and the forking
square (g3) is guarded by the knight on e4.
Yet none of these difficulties need detain you
for long. 1. BxNd7, RxB is a simple exchange
that leaves the Black rook loose; 2. RxN, QxR
loosens the forking square and opens the
needed line; 3. Qg3 calls for Black to reply
Bf8 to stop the mate threat; and then 4. QxR
nets a piece. (4. …Qxg2 gets back a pawn for
Black.)
Now consider a few “why not” questions:
(a) Why not start with RxNe4 rather than
BxNd7? The answer is that 1. RxN allows
Black to recapture QxR and get his queen
onto e4—a powerful posting—too early in the
sequence. For then when you play 2. BxN,
Black doesn’t recapture RxB; he plays Qxg2.
Now the forking square you want no longer is
available (Black’s queen guards it). You have
won two minor pieces for a rook and a pawn,
and if you aren’t careful Black is about to take
another pawn with Rxe3. (Qxh3 also is available to him.) You can win back a pawn with
3. Rxd5, QxR; 4. Qg3 (at last you get to play
the queen fork after all), f7-f6; 5. QxR+. But
the overall sequence isn’t what you had in
mind. Better to start capturing in the back of
Black’s board with BxN, and save the invitation to Black’s queen until you’re ready to
take strong hold of the initiative next move
with a mate threat.
(b) That explanation also shows why, after
White starts with 1. BxN, Black recaptures
with his rook rather than his queen: he’s better off keeping his queen where it can get to
the center of the board after White’s next
move, RxN. And it shows why Black uses his
queen to avenge that last White capture rather
than his d5 pawn: the queen is powerfully
positioned on e4 and in this case can grab the
pawn on g2 after White does his damage.
(c) Finally, when White plays 3. Qg3, why
should Black fend off the mate threat with
Bf8? Why not, say, f7-f6 or g7-g6? Answer:
those pawn moves would allow White to give
check when he plays QxR+, thus forcing
Black to waste a move saving his king when
he should be playing Qxg2.
Dg177: Black to move
Dg177: A demanding position. Inspect for
unguarded White pieces and you find the
bishop (and the queen, but focus on the
bishop). Black has no safe way to check the
White king and attack the loose bishop at the
same time. Does Black have the makings of
any mate threats—any pieces already attacking squares next to the king? Yes: the bishop
at d7 attacks h3. Next: can Black’s queen attack h3 and the loose bishop at the same time?
Yes, with Qh5.
That's the idea. But now Black plays through
this sequence mentally and finds a problem. If
White replies by moving his bishop (say, to
b7 or f3), Black does not quite have mate with
Qh3+. Here, unlike in the previous problems,
the king has a flight square at g1 or h1, and
then there is no way for Black’s queen to
reach it while maintaining protection from his
own bishop.
Still, the basic idea looks promising, so keep
at it. Where a combination doesn’t quite
work, experiment with move order and, above
all, be thorough in examining every check and
mate threat. We have two sequences to think
about, depending on what White does with his
bishop....
(a) Suppose first that White replies to Black's
Qh5 by moving his bishop back to b7. We
had been imagining that Black now would
play Qh3 (and we found that it didn't work).
But what other checks are possible for Black
instead of that one? There is Qd5 (no good—
loses the queen to White's bishop), and there
is Bh3. In response to Bh3 White would have
to play Kg1 or Kh1. You now ask what comes
next, and answer the question by examining
every check. There would be just one:
Qd1―which leads to victory! How? After
White plays RxQ, Black plays c2xR, promoting the pawn to a queen and delivering
checkmate.
(b) Now let's imagine that after Black starts
with Qh5, White moves his bishop to f3
(rather than b7). The initial idea for Black is
the same: give check with Bh3. And again
White is forced to move his king to the back
rank. But this time the follow-up for Black is
a little different. He can't play his queen to d1,
at least not in one move, because White's
bishop on f3 is in the way. So instead Black
does it in two moves. He starts with QxB.
This gives him a bishop on h3 and a queen on
f3, with the obvious threat of mate via Qg2
next move. White's only way to prolong matters is Qb7, so that his queen protects g2. But
now Black uses the same little sequence we
saw in variation (a) above. He plays Qd1+;
and when White replies RxQ, Black recaptures with his pawn, promotes it to a queen,
and mates.
Of course the point of seeing all this isn't that
any of it is likely to happen. You simply are
establishing that if White tries to save his
bishop after Black starts with Qh5, White
ends up mated. So White's best play after
Qh5—and the thing you should expect him to
do—is to abandon the bishop (e.g., with f2-f3,
which at least prevents Black's forthcoming
capture from also giving check).
This is a harder problem than the previous
ones, but it can be cracked with persistence in
examining every check and mate threat, and
then every check that would be possible in the
subsequent position. And of course you must
be alert to the possibility of promoting the
pawn on c2. A pawn on the penultimate rank
(or indeed any passed pawn) always is a
mighty tactical factor; it requires close attention after every adjustment to the board.
a target as a loose piece. Consider it semiloose; it's underdefended. The purpose of this
batch of studies is to drive home the idea that
pieces in such a position make fine targets.
Naturally you could have started your thought
process here by noticing that the bishop was
vulnerable in this way and looking for ways
to attack it while simultaneously threatening
mate.
2.2.12. Mate Threats with Attacks on Underdefended Pieces.
Dg179: White to move
Dg178: White to move
Dg178: The type of fork we now are studying
has two ingredients: a loose piece and a mating threat. You can begin your search by
looking for either ingredient, and here looking
for the second one—the mating threat—might
be easier. There are no loose Black pieces, but
White does have a mate threat of the type now
familiar to us: his bishop attacks h7; his queen
would threaten mate if it were aimed the same
way, and this can be accomplished with the
easy Qe4. That move also attacks the d4
bishop; too bad it isn’t loose. Or is it? Actually it's attacked once (by the White knight)
and protected once (by the Black queen). So if
White attacks the bishop again with his
queen, he wins it. Normally, of course, Black
would respond to such a threat by moving the
bishop or increasing its protection. The point
of the fork is that it deprives Black of time to
do those things.
Dg179: The pattern repeats. You are cultivating awareness of your mating threats, and for
White the pattern here is familiar: the bishop
at d3 attacks h7; if White’s queen also were to
attack h7, he would threaten mate and Black
would have to spend a move fending it off. So
White plays Qe4, also attacking the bishop on
e7. Strictly speaking the bishop isn’t loose,
but it's attacked once (by White’s rook, then
sitting behind his queen) and protected once
(by Black’s queen). So White wins a piece.
Dg180: White to move
This problem is structurally about the same as
those in the previous set, but with the wrinkle
we saw earlier in this chapter: a piece attacked once and defended once—and by a
piece rather than a pawn—can make as good
Dg180: Here is a similar position with a bit
more to see. What mating threats does White
have? The usual: he has the standard bishop
attack on g7; White will have a fork if his
queen can attack g7 and a loose piece at the
same time. Queen moves to c3, d4, and g5 all
are possibilities; the move to d4 looks promising here because it attacks the Black bishop
on e4 while also still protecting the White
bishop on b2, which you see is under attack.
As for Black’s bishop, it isn’t loose but it is
protected once by a rook and attacked once by
a knight. So if White plays Qd4 and Black
replies with some move to fend off the threat
of mate, White then will be able to play NxB
with impunity.
Except that "impunity" is a little too strong.
For here is the new wrinkle to observe: after
White plays NxB, Black will recapture with
his rook and White will take that, too; the
purpose of Black’s recapture will be to attract
White’s queen away from the defense of the
bishop on b2. This way after White plays
QxR, Black has QxB. White still has gained a
bishop and a rook in return for a bishop and a
knight, and thus has won the exchange, but
it's important to see this side consequence of
the idea. The point: account for the defensive
work your pieces are doing before you send
them off to make attacks.
Dg181: White to move
Dg181: Again we have a familiar pattern with
a new wrinkle. White sees that adding his
queen’s weight to the pressure his bishop already imposes on g7 would threaten mate. It
also would attack the bishop at d6, which now
is attacked once and defended once by rooks
from each side. But simply playing Qd4
would be a mistake. You have to think out the
resulting series of exchanges to make sure it
works. After White plays QxB, Black recaptures with RxQ; then White answers with
RxR—and has lost his queen for a bishop and
rook! You have to attend to the values of the
pieces involved. This pattern worked in the
previous frame because Black would have
had to sacrifice his own queen in the recapturing process, but that’s not so here. All this
means, however, is that the bishop is an unsuitable target; it remains to be considered
whether an exchange would improve it. What
if White starts by playing RxB? Then Black
replies with RxR. Now Qe5 safely threatens
both mate and the rook, netting a piece.
Dg182: Black to move
Dg182: The initial idea here is familiar. Look
for a mating threat for Black’s queen. Black’s
bishop at c7 is attacking h2. Qe5 thus suggests itself, as it creates a mate threat against
h2 and also attack the knight on d4. The
knight is attacked once and defended once, so
as we have seen it is a good target for a double attack. But we also have seen that it is
important to pay attention to move order.
Should Black play Qe5 and plan RxN on the
next move? Or should he try RxN first and
then play Qe5 after Black recaptures with
RxR? This time you find the answer by asking what replies White could make after
Black's initial Qe5. Don't automatically assume that White will move one of the pawns
in front of his king; another possibility would
be to play Nf3—shoring up the protection of
h2 and also moving the target of the fork to
safety. (You always want to ask whether the
target of a fork would be able to jump to
safety and block the check—especially when
the target is a knight.) The preliminary exchange 1. …RxN; 2. RxR therefore is the way
to go; then Black can play Qe5 and win the
rook, as there is no way for White to move the
rook and protect against mate at the same
time.
The previous few problems show the importance of thinking about various move orders.
Sometimes, as in this case, these patterns are
best resolved with a preliminary exchange
that puts a new piece on the target square;
sometimes it's best to just play the mate threat
and then perform an exchange afterwards—
especially if a preliminary exchange would
put a new piece on the target square that
would be able to defend itself against a double attack. It all depends on how the exchanges would play out. The general lesson,
applicable here and elsewhere: don't take
move order for granted.
Dg183: Start with the position. Scan for loose
Black material and you find the rook at c5
(and the queen; but focus on the rook). White
has no way to attack it and give check at the
same time, but do not give up; study the
Black king’s position carefully. What are the
constraints on its movement, and what are its
resulting vulnerabilities? It is stuck on the
back rank with no defenders there. If White’s
queen or rook were to land on the back rank,
it would be mate. So the back rank itself becomes a target in just the way that a loose
piece would be; White’s goal is to attack the
Black rook and the back rank at the same
time. What move threatens both? Qb4, winning the rook after Black fends off the threat
of Qb8+ (and QxQ# after Black interposes his
queen) with a move like h7-h6.
2.2.13. Other Mating Threats.
The mating threats considered so far all have
involved a attack by the queen on a square
already attacked by another piece—typically a
bishop. That is the most common sort of mating threat to use as part of a queen fork, but
there are others as well; here we'll consider a
few examples. Many of them involve an initial move to set up the fork (a check, capture,
or threat) followed by a double attack that
includes a mating threat. Like the studies toward the end of the chapter on knight forks,
they require a willingness to play with the
consequences of various checks and captures,
always asking about the next check that
would be available and looking for familiar
patterns to emerge.
Dg183: White to move
Dg184: White to move
Dg184: White has no promising checks or
mate threats, and only Black’s rooks (and a
pawn) are loose. Experiment with captures to
see how they and the responses they force
would change the board. White has an interesting one available in Nxe5; Black would
reply NxN. Evacuating the knight from f3
would open the familiar line for the queen to
reach h5, and from there to check the Black
king. Qh5 also would attack the Black knight
that would then be at e5.
At first this looks like a perfect double attack,
but actually it isn’t; for consider as well what
move you then would make if you were in
Black’s shoes. As we recently saw, a common
hazard of making a knight the object of a
double attack is that it can jump out of harm’s
way and block the check at the same time.
That would happen here: Black would play
his attacked knight from e5 to g6. But just
keep pushing, always asking what lines would
then be open and what checks then would be
possible. With White’s queen on h5, Black’s
knight over on g6 instead of on c6, and the e5
pawn off the board, White has another, more
effective attack: recall that the a8 rook is
loose; and now White has a fresh mating
threat to create with Qd5, adding to the
bishop’s existing attack on f7 (remember that
a bishop attacking that square early in the
game always is a promising setup for a double
attack). After Black fends off the mating
threat, White takes the rook with his queen.
If you look at the original position again you
might be able to see the outlines of a fork
waiting to happen: if White could get his
queen onto d5 and clear the c6 knight out of
the way, he would win the rook on a8 by creating a mate threat against f7. But making
those adjustments takes a couple of moves
and requires the queen to take a circuitous
route.
Dg185: Black to move
Dg185: White has a loose rook on g5. Black’s
queen has no checks, and the mating threat
Qd5 doesn’t work because White's rook
guards the square (as well as g2). But there
are other ways one can threaten mate. Study
the constraints on White’s king. It is blocked
by its own pawns. Qe7 thus attacks the loose
rook and threatens mate on the back rank with
Qe1. But this is another of those cases where
you have to ask whether White might save the
target and defuse the mate threat at the same
time. The rook can’t do this by moving, but
White does have the simple resource of h2h4, guarding the rook and giving the king an
escape square. Yet as we saw most recently in
the previous problem, this sort of possibility
should not discourage you. Ask what check
would then be possible, and with what consequences. Black could play Qe1+, which
would force Kh2. And then what check could
Black offer? Qxh4—checking the king and
again attacking the rook, and this time winning it. It's all about persistence with checks.
Dg186: Black to move
Dg186: The knight on c4 is the important
target here—important because it lies loose
on the same rank as Black’s queen. Black
wonders if he can find a way to attack the
knight and White’s king at the same time. The
idea would be to get the pawns out of the way
between the queen and knight, and to use the
g-pawn to support a mating threat by the
queen that keeps White busy. Clearing away
the White pawn at e4 is the first order of
business. Black attacks it with nothing, and
anyway capturing would not help because that
still would leave the fourth rank cluttered. No,
the other standard route is a better way to remove the pawn: capture something it protects,
here the d5 knight. Black plays BxN, White
replies e4xB, and now the c4 knight is more
vulnerable. Next Black needs to move the g4
pawn out of the way and also create a threat
with it. The question suggests its own answer:
g4-g3 gets the pawn off the fourth rank and
also attacks a weak square adjacent to White’s
king, creating a threat of mate with Qxh2+
followed by Qh1#. White easily parries all
this with h2xg3, but this costs him a move,
after which QxN follows.
After Black’s BxN, White also has the option
of g2-g3, attacking Black’s queen. At first this
looks good; if the queen can be driven away,
maybe White will be able to take the Black
bishop without the fork Black has planned as
a follow-up. But it turns out not to be advisable; for Black has the reply BxNc4, capturing another piece, unmasking an attack by his
rook on White’s queen, and aiming his bishop
at the White rook on e2. White has to respond
by playing his rook to d2, giving it protection
and also protecting the queen on d1, giving
White a chance to move his queen out of danger with a gain of two pieces. Still, the idea of
White's counterthreat (g2-g3) is valuable to
see, as is the discovered attack against the
White queen that makes Black's riposte
(BxNc4) so powerful. We will study discoveries in more detail later.
h3, Nh6; 2. Qe4 wins the rook. (Black would
be better off just forfeiting the knight.) The
hardest part about this one is seeing that
Black's knight would have to go to h6. Remember that a threatened knight often has
limited options, and that when it is forced to a
new square there may be interesting side effects.
2.2.14. Attacking Two Loose Pieces.
Dg188: Black to move
Dg187: White to move
Dg187: What Black pieces are loose? Just the
rook at c6, so White looks for ways to attack
it while giving check or threatening mate.
Qe4 seems awfully close to working; it attacks the rook and, along with White’s knight,
threatens h7 for a second time. The hitch is
that Black’s queen also protects h7, and
White has no way to drive the queen off.
Once White sees that only the Black queen
stops the winning fork, he focuses on how he
might get rid of it—perhaps by harrying it
with his pawns. White starts his kingside
pawns forward with a threat against Black's
knight: h2-h3. Where would the knight go? It
turns out to have only one safe square: h6.
Ah! The knight then would block the Black
queen’s route to h7. Suddenly there is no need
to drive off the queen after all; now White's
Qe4 would create a serious mating threat because Black’s queen wouldn't be able to help,
and the rook at c6 remains loose. So: 1. h2-
Dg188: Queen forks most often have the enemy king on one prong, but of course two
loose enemy pieces also can make fine targets
for a double attack. Thus diagram above, it is
easy if you take the time to ask the right questions. What White pieces are loose? Answer:
the bishop at a6 and the rook at h1. Of course
you might look for a way to give check while
attacking one of them; but don't forget to also
ask whether Black’s queen might attack them
both at the same time. If the answer isn’t obvious, look for a square where lines leading to
both loose pieces intersect, and ask whether
the queen can get there. Here Qc6 wins the
bishop, since after it is played White only has
time to defend the rook.
Dg189: Again, there is nothing difficult here
if you ask (a) which White pieces are loose
and (b) whether there is any way you can attack them at the same time. Here both of
White's rooks are unguarded (loose rooks in
the corner of the board is pretty common, and
make nice targets if the pawns diagonal to
them—e.g., the g2 pawn in this example—
have been moved).
Dg189: Black to move
Look for a square where lines leading to both
pieces intersect; see that Qe4 wins one of the
rooks.
Meanwhile the pawn on h3 is essential here,
too, since otherwise 1. Qe3 is met with the
knight fork Ng4+. You want to ask in any
position not just whether you have any forks
to give but also whether the enemy does—and
whether he will have any after the move you
are considering. This is particularly important
when, as here, Black already has a knight
check to give on g4. This means you have to
think twice about putting your queen on a
nearby dark square where it might get forked.
Fortunately it's not a problem in this case because you have a pawn at h3 guarding the
forking square.
Dg191: White to move
Dg190: White to move
Dg190: Here is nearly the same pattern turned
sideways. Black has two loose pieces: his
rooks. Lines to them cross at several junctures
(e.g., g1 and h6), but the only useful intersections are those that allow the rooks both to be
attacked on diagonals, making it impossible
for them to defend themselves by going after
the attacker. So the winning move is Qe3,
picking up a rook a move later.
This much is easy, at least if you are alert to
loose pieces; but now notice a couple of finer
points. The fork only works because of the
pawns at b2 and h3. Do you see why? The
pawn at b2 is critical because otherwise Black
could move one of the rooks to protect the
other. It always is important to ask whether
your opponent would be able to break a fork
by moving one of the pieces out of it to protect the other, to check your king, or to otherwise create trouble. It's an especially important issue when you are forking two pieces
that both have mobility, as these rooks do.
Dg191: Which Black pieces are loose? Both
rooks and the knight. Can White’s queen attack two of them at the same time? Yes, easily via Qd4, winning the knight. Here the
queen is just behaving like a bishop; we will
see lots of positions like this when we examine bishop forks.
By the way, Black has the option of replying
to Qd4 with RxNb1, thus limiting his immediate material loss to the exchange. White
replies RxR; Black moves his queen to d8 to
guard the knight; and now White has e4-e5, a
little fork that wins a pawn. Meanwhile
White's b1 rook is now in a much stronger
position than before.
Dg192: Again both enemy rooks—this time
the White ones—are loose. Black’s queen
can't attack them at the same time, but it can
go after one of them with Qd3; so if he could
create another target reachable from that position he would have a working fork. The rook
on e1 cries out to be drawn forward with an
exchange—such as Bxe2.
Dg193: White to move
Dg192: Black to move
If White replies RxB, now both rooks still are
loose and can be attacked with Qd3. (White’s
best bet is not to recapture Black’s bishop; if
he does and then finds himself forked, his
most favorable option is Rxe6, at least using
one of his rooks to take a pawn on the way
down.)
By the way, notice the predicament faced by
Black’s g4 bishop at the outset here. It's under
attack and almost has nowhere to go. If it
were to retreat to h5, White would have g3-g4
and would win the piece a move later; if
Black instead were to play Bf5, White again
traps the bishop with e2-e4. Fortunately for
Black he has this other “out” of Bxe2, leading
to a queen fork. But you can learn from this
near-catastrophe for Black by studying the g4
bishop and the Black pawns behind it. This is
a classically poor position for a bishop: its
lines of retreat blocked by its own pawns and
by the edge of the board. When you see an
enemy bishop so positioned, realize that it
may be unusually vulnerable to attack.
Dg193: Look for loose Black pieces that
might serve as targets and you come to the
knight at h5 and bishop at d6. Ask if the lines
to those pieces intersect anyplace the White
queen can reach and you are led to Qd1. Or
now think about this position from a defensive standpoint. Black just made the move
Bd6, a mistake that turned out to lose him the
game in the way just described. How would
you avoid making such a move?
By asking the same question about your own
pieces that you ask about your opponent’s:
which of them are loose, or will be after the
move you are considering. And then you treat
every loose piece as a vulnerability. In this
position Black’s loose knight at h5 already
was unfortunate and was a reason to pause
before also moving the bishop to an unprotected square.
Dg194: Black to move
Dg194: Another defensive study. Black has a
problem: his knight on c6 is pinned, and is
attacked twice and guarded just once. He is
imagining 1. BxN, b7xB; 2. Qxc6+, forking
king and rook. So Black thinks about moving
his c8 bishop off the back rank to d7, shoring
up the protection of the knight. It's a blunder.
Remember to ask whether a move you consider will leave anything unprotected. This
happened in the previous position when a
piece was moved to a square that had no protection. That isn’t a problem here, since the
bishop will be safe on d7. But you also want
to look at any lines a move affects. The point
is the knight on d5. It's protected by the
queen. The knight’s protection is cut off if
Black plays Bd7; it becomes loose.
Once you see this, it isn't enough to ask just
whether the knight now is under attack. Loose
pieces can be taken for free by forks. Is your
king also exposed to attack? Do you have any
other loose pieces? Where is your opponent’s
queen? Here your study of those questions
would show that you already have an unprotected bishop at c5. So Bd7 would leave two
loose pieces right next to each other. And
White’s queen is close at hand: on a4, ready
to play Qc4 and win one of those two pieces a
move later.
to see is that from c1 White’s queen would be
aimed at the Black knight on h6.
Dg196: White to move
That knight already is attacked once and defended once, which is to say that it’s as good
as loose. Adding an attack against it by the
queen amounts to a queen fork of Black’s
bishop and knight. Black probably responds
with the interposition Nc6, allowing White to
play BxN next move.
Dg195: Black to move
Dg195: White’s rook at f1 is unprotected and
so is a target, but there is no way for Black to
give check and attack it at the same time.
Still, when you see any loose piece it pays to
think hard about ways to attack it and create
problems elsewhere with your queen. Here
Black’s queen can attack the rook with Qc4,
which also attacks the knight at h4. So examine the knight’s situation and notice that it is
attacked once and defended once, and defended by a piece rather than a pawn—as
good as loose, as we have seen elsewhere
(you might just as well have spotted all this
by regarding White's knight as a good target
from the outset). Qc4 thus wins the knight,
because after White moves the rook Black
plays BxN and White dares not recapture. (If
White replies to Qc4 with Qf2, protecting his
rook, Black plays BxN just the same.)
Dg196: A loose piece can make a fine target
even when it lies in its original position on the
back rank. Here Black’s bishop on c8 is loose;
White can attack it with Qc1. But this only is
interesting if the attack can be paired with a
simultaneous threat elsewhere. The key point
We have seen many times the importance of
being aware of loose pieces. But it likewise is
important to be aware of pieces attacked once
and protected once; they often make targets
for forks that are just as good as pieces with
no protection at all.
Dg197: White to move
Dg197: A cursory look at White’s attacking
options turns up Rxb7, taking a pawn for free.
But even when you have a simple capture
available it's worth asking whether you might
have something still better. Standard procedure for the purpose, of course, is to experiment with any checks you can give; safe
checks with your queen are especially impor-
tant because they may in effect give you a
free move. Here White has one in Qd3. It
forces Black to move his king to the back
rank or play g7-g6. Either way, ask what
White could do next. Answer: fork Black’s
rooks with Qd7, taking one or the other of
them a move later.
Of course another way to see this is by scouting for loose pieces on the board. Two loose
pieces, as Black has here—and on the same
diagonal, no less—beg to be forked. You see
that your queen needs two moves to get to the
forking square; so you ask whether you can
make the first move a check that will keep
Black busy. This leads to Qd3 as a transitional
move.
A natural mental sticking point here is to start
looking at the check Qd3 and then give up
when you conclude that you then have no
good follow-up against Black’s king. The
trick is to be flexible enough in your thinking
to move from looking at checks against the
king to looking at follow ups against other
pieces. In this case the power of the check
Qd3 isn't that it forces Black’s king to change
squares; it's just that it gives White a way to
move his queen across the board while denying Black a chance to respond. Anyway, if
you are conscious of the two loose rooks in
this position you won’t overlook 2. Qd7, because you will be thinking all the time about
how to get at them.
2.2.15. Attacking Two Loose Pieces: More
Procedures.
Dg198: White to move
Dg198: How many Black pieces are loose in
the position ? None (setting aside the pawn at
e5). Nor does White have any productive
checks. But we also want to examine the results of every capture. RxB is the only one
White has to consider; it results in RxR. Now
how many Black pieces would be loose?
Two: both rooks. The problem then becomes
the easy one of finding a square—c6—from
which White’s queen can attack the rooks
simultaneously. Ask what Black’s response to
Qc6 would be; might it be possible for one of
the rooks to rush to the defense of the other?
No, but only because of the placement of
some pawns: the b3 pawn prevents either rook
from moving to a4, and the e5 pawn prevents
Ra8-e8 from being useful. If either pawn were
missing, the fork wouldn't work.
That's one lesson of this problem: the importance, as we have seen elsewhere, of considering whether one forked piece can move to
protect the other. The other lesson is that a
single exchange—here, 1. RxB, RxR—can
radically change the board; in this case it
moved Black from having no loose pieces to
having two of them.
Forks that attack two loose pieces can run into
most of the same obstacles as forks that include checks on the king. There is no need to
catalogue them exhaustively here; once
you've found a forking square, the task of
loosening it for occupation by your queen
generally is the same regardless of whether
the fork involves a check, a threat of mate, or
an attack on two loose pieces. But here are a
few examples of how the familiar problems
discussed earlier look in this context.
Dg199: Black to move
Dg199: Black recently moved his bishop to
a3; then White took it with his b-pawn. Now
it’s Black’s turn again, and time to figure out
why he let his bishop get taken. Look for
loose White pieces and you come to his
rooks—and see that the diagonals leading to
them now are open on both sides. Black can't
attack them both at once, and he has no
checks or useful captures to consider. But it's
important also to consider threats, since the
replies to them tend also to be forced; they let
you hold the initiative and control the play.
Here you ask which Black pieces can attack
either White rook. There is only one answer:
Qd4. It doesn't win anything by itself, but ask
anyway what will White play in response.
Suppose he moves the rook to b1. Now ask
the same questions: you still are trying to
make something out of the two loose Black
pieces—and now you can attack them simultaneously, with Qe4. (White’s better reply to
Qd4 thus is Bb2, interposing his bishop; it
gets taken next move—for now it, too, has
been left loose—but then White at least has a
move to save his rook.)
This position is a good example of a point
made earlier: a rook frequently is unprotected
when it sits in the corner of the board, and so
is vulnerable to a fork if its diagonal pawn
cover is blown. This is an unusual case where
both rooks are in that position. Think about it
if you or your opponent moves the pawns at
b2, b7, g2, or g7 early in the game.
camp: the rook on c8 and the bishop on h6.
His immediate thought is to pair an attack
against one of them with an attack on Black’s
king, or to attack the two of them at the same
time. The natural weapon for either purpose is
the queen. It's well-positioned for action on
g3. White looks for a square from which his
queen could take advantage of the loose Black
material and sees that Qh3 aims the queen at
both bishop and rook. The only hitch is the
pawn in the way on e6. The usual procedure
for removing a bothersome pawn is straightforward: take something it protects. Thus
White begins with RxB, inviting the recapture
e6xR; now Qh3 forks the loose Black pieces
and takes one of them next move, winning
two pieces for a rook (and leaving White
ahead by a whole piece, as he already was up
the exchange).
It all would be even better, by the way, if
White’s rook were on d1 instead of d2. In its
actual position here White’s rook is en prise
to the bishop on h6; so if White starts with
Qh3, Black has BxR. If the rook started on d1
there would be no such threat and White
could make Qh3 his opening move. The move
isn’t quite a fork, but it threatens the loose
bishop on h6 and also pins the pawn on e6,
thus creating a fresh loose piece on d5. Black
most likely would respond by moving the h6
bishop to safety on f4 (Kg7 is another possibility); and then White can play RxBd5, winning a piece cleanly since Black won’t recapture (if Black does play e6xR, White has QxR
and still has the piece). We will examine the
creation and use of this sort of pinning move
in a later section of this project.
Dg200: White to move
Dg200: It's hard to overstate the importance
of loose pieces in chess—noticing them, creating them, and exploiting them. Loose piece
= target. Here White sees two in the enemy
Dg201: White to move
Dg201: How many Black pieces are loose?
Two: both knights. There is no way to attack
them at the same time, and no way to attack
either of them while threatening the king in
some way. Those loose pieces nevertheless
are tantalizing targets, so White starts digging
for ways to attack one of them and something
else of value at the same time. The simplest
way to do this is by just looking at squares
from which the queen can attack either
knight, and then seeing what else can be attacked from the same squares: if not a loose
piece, then perhaps a piece that can be made
loose. White’s queen can attack the g3 knight
by moving to c3 or d3. From d3 the queen
also would attack the bishop on a6. That piece
isn't loose, and anyway it can strike back at
d3. Since White has a target, but one that
doesn’t work, he looks for an exchange that
would improve it: he can play BxB, provoking RxB. Now d3 has been made safe for
White queen and Black has a loose piece—
the rook—on a6. Qd3 thus attacks two loose
pieces and wins the knight.
You also could have found this by just examining every capture of a piece by a piece that
you can initiate: imagine 1. BxB, RxB; ask
whether that exchange leaves behind any
loose pieces; see that the rook would then be
loose; look for ways to attack it along with
another loose piece; find Qd3. Either way,
this problem resembles the earlier ones where
White’s queen had a clear path to a square
from which it could attack the king, but
needed to loosen the other target with a preliminary exchange to create a good double
attack. In other words, imagine that the g3
knight in this problem is the Black king, and
the rest of the problem then becomes structurally the same as many we saw earlier in this
chapter. The implication: if your queen can
attack a loose piece and any other piece, start
asking whether the other piece can be loosened (or replaced with something loose) as
well.
Dg202: This position may seem elusive if you
flail about at random, but it comes apart easily
with methodical interrogation. Which Black
pieces are loose?
Dg202: White to move
The bishop and both rooks. (You might look
for ways White’s queen could attack any of
them and also the king, and come up empty:
the needed squares—e.g., d4, d7—are protected.) Since there is more than one loose
piece, try attacking two of them at once. Look
for a square from which this could be done
safely with the queen. You attack rooks from
diagonals and bishops from ranks or files, so
that the targets can't strike back. The h4 rook
and e6 bishop could be attacked from e1, or—
if the king weren’t protecting it―from f6.
The queen can’t reach either square in one
move, so see if it can get there in two moves,
with the first one a check or other threat that
controls Black's response. Qc3+ requires the
Black king to move to h7; then Qe1 forks the
rook and bishop. Black can't escape the loss
of a piece. (If White instead plays the forking
move Qf6, Black can use the rook to protect
the bishop: Re4.)
You also could have found this by just examining every check. The queen has checks at
c3, d4, d7, and g6. Only c3 is plausible; all
the others result in the queen being captured
without an adequate follow up. So you ask
what would be possible after the king is
forced to move. You are mindful of (a) any
loose pieces, (b) the king’s new position on
h7, and (c) the White queen’s new position on
c3. Qe1 then is simple enough.
Dg203: White has no checks or captures to
consider. There remains one other sort of
forcing move that at least partially dictates the
enemy response: a threat, especially by a
pawn; these tend to be very effective forcing
moves because your opponent generally can't
afford to lose a piece for a pawn. So try e2-e3.
Where will the Black knight go?
Dg204: White to move
Dg203: White to move
Look at the ring of eight light squares within
its range, and see that only two of them are
safe: b5 and f5. As usual after any sequence,
you then ask what pieces would be loose,
what lines would be open, and what attacks
would be possible. Here the knight and bishop
both would be loose (surely you saw the loose
bishop from the start), and the movement of
the e pawn would have opened a line for the
queen. It is urgent that White look for ways to
take advantage of those two loose pieces in
the middle of the board. If the knight moves
to f5, White can use the new open line to play
Qg4, attacking knight and bishop at the same
time. If the knight moves to b5, White can
attack both pieces with Qa4.
The most important things about this problem
are (a) not to overlook threats by pawns; they
are forcing moves, and can cause big changes
on the board—loose pieces and open lines; (b)
to remember when thinking about White's
second move that the e-pawn would be out of
his queen's way; and (c) not to just assume the
Black knight will “move somewhere” if attacked, but instead to examine its actual options and patiently consider what you could
play in response to each of them. If the position were slightly different the fork at the end
might not have worked; the knight might have
been able to retreat to a safe square. But the
benefits for White if the Black knight does
end up loose are great, so a careful study of
where the piece can go is fully warranted.
Dg204: Two Black pieces are loose: the rook
at a8 and knight at h5. Look for a square from
which the queen might attack both. The lines
to them intersect at e8 (way too hard to reach)
and d5 (more feasible—White’s queen can
get there in one move). The only problem is
that the pawn on c6 both blocks the path to
the loose rook and protects d5. We handle this
with an exchange, of course, drawing the c6
pawn forward by capturing its protectorate. 1.
Nxd5, c6xN and now the problem is in simpler form; you see that d5 is occupied but
unguarded and the paths to both rook and
knight are clear. Qxd5 suggests itself as a
working fork.
But now pause and reflect on Black's reply to
Qxd5. One of his forked pieces, the knight on
h5, is positioned aggressively. Black might be
able to break out of the fork by using that
knight to do some damage. Indeed, he might
play NxBf4; then if White carries out the fork
with QxRa8, Black has Nxe2+, a fork of his
own. So to prevent all this White doesn't follow 1. Nxd5, c6xd5 with Qxd5 right away. He
first moves that vulnerable bishop off of f4,
and he does it with a threat that holds the initiative: Bc7, attacking Black's queen. Notice
that the bishop has protection on c7 from the
rook back on c1, because Black's c-pawn is
gone by that time. Black thus moves his
queen—and now White can go ahead with the
queen fork on d5, because Black can't use his
knight to make a capture in reply; the piece he
might have wanted to capture—White's
bishop—is no longer there.
If Black is alert, of course, he will not recapture on d5 in the first place; he will let the
pawn go rather than subject himself to all that
has just been described. As often is the case,
the value of the threatened fork is that it permits other, lesser gains by making it too
costly for your opponent to recoup his losses.
(Here Black can reply to Nxd5 with NxB,
removing his loose knight from the coming
fork; then White has Nd5xN, keeping the
pawn.)
It all starts simply: by noticing loose pieces
and asking whether you can make a double
threat that includes at least one of them. If
you do that, seeing the fork is reasonably
easy. If you don't, it's hard.
no matter how short; likewise keep track of
the open lines left behind by any forcing sequence you can find, no matter how short.
2.2.16. The Enemy Queen as a Target.
Usually your opponent's queen makes a poor
target for a queen fork because it can defend
itself by attacking the attacker. Part of the
beauty of the knight fork is that a knight, on
account of its unusual pattern of movement,
can attack an enemy king and queen without
being subject to capture by either of them; the
queen as an attacker generally does not have
that advantage. The exceptions are cases
where, if the attacked queen does defend itself, the result is mate—most commonly on
the back rank—or else another combination.
Dg205: Black to move
Dg205: Start with a routine inspection for
loose White pieces; find the bishop at c1 and
rook on e8—and then focus on the bishop.
Black has no checks that also attack the piece,
so he plays with other forcing moves. He has
only one capture to consider: BxB, to which
White would respond KxB. When you ponder
such an exchange, think about what pieces
would be left loose and what lines would be
opened by it. The answer to the question
about loose pieces is that the king’s move to
h3 would leave a loose knight on h1; the answer to the question about open lines is that
taking the Black bishop off the board opens a
clean line for the Black queen to g1. Put these
points together with the loose bishop at c1
and we have an easy double attack against
two loose pieces: Qg1 wins the knight.
Notice how the same principles emerge time
and time again: keep track of the loose pieces
on the board, but also the pieces that are left
loose by any forcing sequence you can find,
Dg206: White to move
Dg206: In this first example, start by examining the Black king’s position and the constraints on its movement. It is stuck on the
back rank. White can launch an attack there
with his rook on the e-file; if the Black queen
weren’t in the way, Re8 would be mate. “If
his queen weren’t there, I could mate”—many
combinations begin with a counterfactual like
this, which is why imagination plays such a
large role in chess. Here the point of the insight is that Black’s queen is unusually vulnerable to attack because of the crucial defensive work it is doing. It also is loose, and so is
Black’s bishop, so White looks for ways to
attack them at the same time. Their lines intersect at b4, so White plays 1. Qb4. If Black
plays QxQ, then White ends the game with
Re8#.
We aren't quite done with the analysis. After
1. Qb4 Black will look for some other way to
save his queen and avoid disaster. What will it
be? Moving the queen to c8 where it seems to
protect the bishop is no good, of course, since
play then goes 1. Qb4, Qc8; 2. QxB, QxQ—
followed, again, by 3. Re8#. Black might instead move his queen to a safe square like g8,
but his best reply to Qb4 probably is Nc6. Do
you see why? It opens a line from Black’s
rook on a8 to his queen, so that the queen no
longer is loose. Now White has a choice of 2.
QxB or 2. QxQ, RxQ; d5xN. Either way he
wins a piece, but the latter sequence is a little
stronger because it also takes both queens off
the board, magnifying the significance of the
advantage White gains.
But then White has 2. RxR, QxR; 3. QxN,
still winning a piece.
Think of our current theme this way. We have
been studying double attacks; these are simultaneous attacks on two vulnerable points at
the same time. A loose piece is a vulnerability, as is the king. If you attack them at the
same time, you generally win one or the
other. We also saw that even a mere square
can be a vulnerability if the queen would deliver checkmate by landing on it; attacking
such a square—and thus creating a mating
threat—can be as good as attacking the king
itself for purposes of creating a double attack.
Now we are adding still another point on the
board that qualifies as a vulnerability: a queen
that is defending against mate. Once you see
this—once you identify a way that you could
deliver mate if it weren’t for the enemy
queen—then attacking the queen becomes
itself a kind of mating threat. The usual
worry, which is that if you attack the queen it
will bite back, is out of the picture.
Dg207: White to move
Dg207: The principle here is similar. Black’s
queen is loose. As a matter of course you also
study the constraints on the enemy king’s
movement and ask whether you have any sort
of mating threat in view. Again White nearly
has a mate on the bank rank: if the Black
queen leaves its post, RxR is checkmate. In
effect the queen is stuck where it is; the protection it provides the knight is illusory, so the
knight is as good as loose. Look for a square
from which White’s queen can attack the
knight and queen at the same time, taking
advantage of the queen’s paralysis. The
search leads to Qf7. If Black replies QxQ,
White plays RxR#. So instead Black plays
Qc8 or Qb8, and White takes the knight. (If
Black then plays QxQ, once more White can
play RxR#. Here as in the previous problem,
the queen is committed to guard duty on the
bank rank.) Or 1.Qf7 can be met with 1.
...Kb8, which gives Black's queen a guard.
Dg208: White to move
Dg208: What Black pieces are loose? All of
them: rook, bishop, and queen. What sort of
shape is Black’s king in? Not so good: once
more it is stuck in the corner behind its own
pawns with no defenders on the back rank.
Rd8 would be mate if it weren’t for the Black
queen defending that square. This fact should
ring a bell: the queen is preventing mate. So
White looks for a way to build a double attack
against the queen and something else. The
natural second target is the loose rook. White
can play Qe5 or Qe3, attacking both queen
and rook; these moves look brazen, but if
Black plays QxQ White plays Rd8 and it’s
mate (after Black uselessly interposes his
queen and rook and White’s rook takes each
of them). So Black responds to Qe5 by retreating his queen to avoid mate—or, better,
by moving his bishop to e6 to block the attack. White then wins the rook.
The initial step in all these positions is to see
if you are anywhere near threatening mate—
and this includes mate threats that would exist
if it weren't for the enemy queen. These can
be hard to notice because mate looks so impossible. The queen prevents it, and your
mind stops there. But now you will be more
likely to spot such cases anyway because you
realize what they mean: the queen itself can
become a fine target.
Dg209: White to move
Dg209: Examine the Black king’s position. If
White safely could play RxR on f8 the game
would be over; but Black’s queen guards the
rook and so prevents this. This makes the
queen vulnerable to attack, as it cannot afford
to leave its post to defend itself. Consider
ways of going after it. If White attacks the
queen with Qc2, Black can reply by simply
moving it to d6 where it still does the same
defensive work. White needs a way to
threaten Black’s queen while also threatening
something else. Black’s other pieces have
guards or are inaccessible, so what else can
White threaten? Again, focus on Black’s king.
White’s rook not only threatens RxR; it also
attacks a square next to the king (g7). If
White’s queen were aimed at that square, it
would threaten mate. So White does have a
double attack: with Qe5 he can attack both g7
(a mating square) and Black’s queen (another
vulnerability—it can’t strike back). Some-
thing has to give, and it’s the Black queen.
Black plays RxR to avoid mate, but then suffers QxQ and the game is over anyway.
The point, of course, is that once the enemy
queen becomes a good target for a fork because it can't afford to move, you can combine it with all sorts of other threats: attacks
against other loose pieces, attacks against the
king, or—as here—attacks against mating
squares. To see this last option you need to be
alert to multiple mate threats you can make.
By assumption you already see one—RxRf8;
that's how you realized that Black's queen
couldn't move. The trick is to remember there
might also be a different one that then can be
made the basis of a fork: you can add a threat
by your queen against g7.
Notice, finally, that the same effect could be
achieved in a more roundabout fashion by
pursuing that first idea—Qc2—a little farther.
We saw that Black can reply with Qd6; but
then if White plays Qd2 he attacks Black’s
queen again. Black moves it back to c5, creating the same position seen in the diagram but
with White’s queen now on d2 instead of e2.
White then can play Qd4, again forking
Black’s queen and the mating square g7. The
reason to bother noticing this is just to remember that sometimes there may be more
than one forking square and more than one
way to get there. Since perfecting such a fork
ends the game almost as surely as checkmate,
it is worth carefully studying all the ways you
might make it work.
Dg210: White to move
Dg210: This position only sort of fits in this
section, but it's instructive nevertheless. On a8
Black has left a loose rook with an open diagonal running toward it. White has no good
mating threats but his knight is in an intriguing position: it attacks e7, from which square
it would check Black’s king. Be alert for forks
anytime the knight is one move from attacking the king. Meanwhile White looks for
ways to threaten the loose rook and sees that
one of them is Qc6, which attacks both rook
and queen and requires a reply: perhaps QxQ.
Ask how the board would look after that
small sequence, and notice that Black’s king
and queen both would be on light squares—
ready to be forked with NxB, which wins the
bishop for White when the smoke clears.
Now don’t forget to ask whether Black’s
queen, when attacked by White’s queen,
could both move out of harm’s way and defend the other attacked piece. Suppose, for
example, that instead of playing QxQ, Black
plays Qb8. Now White’s queen can’t take
Black’s queen or rook. But—aha!—the
bishop at e7 would be left loose by the
queen’s movement, so White could play NxB
with impunity. If Black instead had played
Qd8 so as to protect both bishop and rook,
White again envisions NxB. Black could answer with QxN; but then the rook would be
loose (Black can’t have it both ways), and
QxR+ takes it.
So the result is that Qc6 is a working queen
fork of Black's queen and rook—though this
time without a mate threat in the background.
Instead it works because Black's queen is vulnerable for a bunch of other reasons: it can
move only at great cost, because it is doing
other defensive work (guarding the bishop
and rook) and because if it captures on c6 it
lays itself open to a knight fork.
2.2.17. Summary; Strategic Implications.
Now consider some strategic implications of
our study of queen forks, along with summaries of several repeating ideas:
1. Appreciating the power of checks. An important purpose of many strategic moves—
moves spent improving your position, rather
than attempting to win material—is to create
fertile conditions for tactical strikes on your
part and poor conditions for them by your
opponent. We have seen that a common form
of one tactical idea—the double attack by the
queen—involves a check of the enemy king
coupled with an attack on a loose piece. The
defensive moral for strategic purposes is
clear: beware any position that allows your
king to be easily checked. It is common for a
beginner to imagine that open lines to his king
are not a big problem so long as the king easily will be able to escape any threat that
emerges, or so long as the opponent only has
one piece to threaten it. Not so; the check itself is a menace, no matter how easily it can
be escaped, because it requires a timeconsuming response. The more ways your
king can be checked, the more ways there are
for you to lose other pieces to double attacks.
This, and not just the fear of checkmate, is
one of the reasons why it is important to castle early; it also is one of the reasons why you
should not casually disturb the pawns in front
of your king, since you then create open lines
that make checks and mating threats—each of
which may be half of a fork—easier to create.
To turn the point around, one of the general
goals of this chapter and the others is to
change the way you think about checks. They
are immensely useful weapons in the tactician's arsenal not because they annoy your
opponent or necessarily lead to mate but because (a) they require responses, thus leaving
your opponent no time to address any other
threats you have made at the same time, and
(b) they require predictable responses, and so
allow you to foresee and control the action on
the board.
2. Captures. Think of captures in a similar
way. Don’t look at a possible capture you can
make, see that your opponent can then recapture, and then decide it’s not worth pursuing;
rather, imagine the way the board would look
after the capture and ask what you then might
be able to do: what checks would be possible;
what pieces would be loose; what lines would
be opened; what further captures could be
made, and where they would lead—all the
time searching for a double threat.
3. Mating Threats. We have seen many times,
too, the power of mating threats. This points
up the strategic value of aiming your pieces in
the direction of the enemy king. Directing
them this way creates not only the possibility
of actual checkmate, but also a favorable climate for threats you do not expect to carry out
but that allow you to make trouble elsewhere
at the same time. You also can see now that
exchanges or threats that open lines to the
enemy king create promising conditions for
tactical moves because they make making
mate threats easier to build. It doesn't matter
that the mate threats are easily met. So long as
your opponent has to spend time addressing
them, they do their work, which is to buy you
a free move to capture something loose elsewhere.
All these points may amount to a new way of
thinking about the moves you make: treating
captures and attacks on the king as means to
achieve other ends, not just as ends in themselves. There are smaller examples of the
same point, too. A beginner decides whether
to move a piece from square A to square B by
asking what the piece will do on square B.
The experienced player knows that the move
may be more important because it vacates
square A and any lines that ran through it, and
blocks any lines that run through square B.
Those consequences may be good or bad. The
important point is to grasp them. Make yourself a student of indirect as well as direct consequences of chess moves.
4. Loose Pieces. We have seen as well the
immense importance that loose pieces have
for the tactician. One of the strategic implications of this can be analogized to military
strategy: it is dangerous to overextend your
forces, letting them wander into enemy territory with little or no protection. Those pieces
can be taken for free if the enemy can make
them the subject of a fork. You therefore
should pause before sending a piece into your
opponent’s half of the board with no protection, or protection only from another one of
your pieces—even if you are putting it on a
square not currently under attack. And from a
defensive standpoint this suggests the value of
denying outpost squares—squares wellprotected by enemy pawns—to your opponent. If he wants to advance his pieces, make
him put them where they will be loose, or
where they only can be guarded by his other
pieces, not by his pawns. Then maybe those
guards can be exchanged or lured away, leaving the first piece loose. (A pawn that protects
a piece is harder to deal with; getting rid of it
by exchanging it for a piece often is too great
a sacrifice to be worthwhile.)
5. Defending the King. The tactical principles
we have studied also shed light on the value
of some basic ideas about good play, such as
the aforementioned importance of castling
early, and of keeping a defensive piece or two
near the king. Without any defensive pieces in
its vicinity, the king is left to defend its own
pawn cover, which means the squares where
those pawns sit are weak, which means it is
easy to force the king to move by taking one
of those pawns and easy for a mating threat to
be set up against them. Maybe the mating
threat can be thwarted easily once it arises by
moving one of the pawns forward, but again
that may be too late to prevent another piece
from being taken if the mating threat was half
of a fork. Likewise, preventing the enemy
king from castling by forcing it to move early
in the game can be very damaging, because
after some exchanges in the center it may then
become easy to throw checks at the king
while also attacking other pieces.
6. Shedding light on some openings. Still another example of how tactical principles
shape strategic decisions: now you can understand why formations like the King’s Indian
Defense (or Attack) are so useful defensively.
Think back to the many forks we saw that
involved mating threats aimed at g7 or h7 (or
comparable squares on White’s end of the
board). Mating threats against those squares
often suggest themselves because those
squares are so weak; as just said, after castling
they often are protected only by the king, so it
is easy to line up a bishop and queen against
them in a way that requires a moveconsuming response. In the King’s Indian
formations (look at the position of Black’s
king in the diagram to the left), mating threats
are harder to create. The h7 pawn has another
pawn in front of it at g6, insulating it from
attack on the diagonal. And the bishop at g7
makes it hard to set up a battery against that
square, either; unlike a pawn, the bishop can
lash out against an enemy bishop or queen
lining up to attack it. Naturally these features
are just one advantage of the King’s Indian
formations, and depending how a game goes
they may not be important. The broad point is
just that tactical insights often can help you
understand the purposes behind an opening.
7. A style of thought. Finally, the studies in
this chapter are meant to help you develop a
more active and aggressive attitude at the
board. Now that you see the usefulness of
open lines and loose pieces, you naturally will
be vigilant in searching for them and creating
them: making exchanges that will leave unguarded enemy pieces in their wake or create
open lines to the king; making pawn moves
that open lines for your queen and other
pieces and that close off lines for your opponent; coordinating your pieces to build mating
threats that you may or may not be able to
carry out but that might enable you to win
material with a double attack. The chessboard
comes alive with these sorts of thoughts once
you understand how they can translate into
tactical payoffs.
Dg211: White to move
2.3. The Bishop Fork.
2.3.1 Introduction.
We have seen that if you want to spot and
create double attacks for one of your pieces, it
helps to have a clear understanding of what its
natural targets are. In the case of a bishop fork
(pictured to the left), as with queen forks, the
most common targets are the king at one end
of the double attack and a loose piece on the
other. There are exceptions, of course, and we
will consider them, but this is the most usual
pattern and the most important to master.
The reasons why this pattern is most common
are by now familiar from our other work on
double attacks. Consider the impediments to a
fork by the bishop—the reasons why attacking two pieces with your bishop might not
work. One of the forked pieces might be able
to capture the bishop if the bishop’s square
isn’t protected; one of the forked pieces might
be able to break out of the double attack by
making a separate threat of its own; the more
valuable or less protected of the forked pieces
might be able to move, leaving at the other
end a piece that has protection (or moving to
protect it). But all these possibilities tend to
be reduced when the king is one of your targets: your opponent is required to address the
threat rather than saving the piece at the other
end of the fork; nor does he have time to use
the piece at the other end to make a counterthreat; and because of the king’s limited mobility, it usually cannot fight back itself
against the forking bishop or launch a counterthreat of its own. And of course a loose
piece at the other end of the fork is ideal because it can be won for free. It just can't be a
bishop, for the same reason a knight is an
unsuitable target in a knight fork: it can bite
back against its attacker.
Our method of finding double attacks by the
bishop, then, generally will resemble those
we've developed elsewhere: searching for
checks the bishop can deliver and pieces it
can attack at the same time; and working to
expose the king and loosen enemy pieces to
create chances for those checks and attacks.
The methods will be easy enough if you have
read the chapter on queen forks. Whereas a
queen sometimes may be able to check an
enemy king in four or five different ways that
need to be considered, the checks a bishop
can make usually are limited to one and never
can be more than two; and since each bishop
runs on squares of just one color, only one of
your bishops can possibly give check at any
given moment. Examining a bishop’s checks
therefore is quick and easy.
Dg212: Black to move
Indeed, you can think of a bishop as a little
like half a queen; it can make the same diagonal moves a queen can make, but not the horizontal and vertical type. Every move we will
see a bishop make is a move a queen also
could make. But not necessarily a move a
queen would make; for the bishop has the
advantage of being worth less than the queen,
and thus easier to sacrifice. Giving up the
bishop to win a protected rook makes sense,
whereas giving a queen for the purpose does
not. We can use this point to add to our list of
targets for forks by the bishop: not only kings
and loose pieces, but also rooks whether they
are loose or not. A rook always is a good target for a bishop, because (a) it is worth more
and (b) its pattern of movement makes it unable to strike back at a bishop that attacks it.
Some bishop forks require not only that the
forking square be available, but that the
bishop be protected. Such protection generally isn't important when building knight
forks because their targets (kings, queens,
rooks, bishops, pawns) don't move in ways
that allow them to strike back at a knight. Protecting the forking square also is unlikely to
be important when creating a queen fork; if
your queen can be taken, the fork probably
won't be worthwhile regardless of whether
you can recapture the piece that takes it.
Bishop forks differ from those types because
sometimes a bishop fork will include the enemy queen at one end of it. Since queens can
move like bishops, a queen always can capture a bishop that attacks it—unless the
bishop is protected. So this is the last point
about the targets for double attacks by bishops: the target can be a queen if the bishop
has protection.
To sum up, double attacks by the bishop generally involve some combination of these targets, listed in rough order of frequency: the
king; a loose knight; any rook; and the queen
if the bishop has protection. (Loose pawns are
fine, too, of course.) Since some of the techniques for making a bishop fork work are
similar to the techniques shown in the chapter
on queen forks, the coverage of them here
will be a bit more brief.
Dg213: White to move
There are a couple of other variables to think
about as you study the bishop. The most important involve the geometries involved when
the bishop inflicts a fork and the visual patterns that result from them. We didn't emphasize this as much in studying queen forks because they can occur in so many ways that
have little in common visually. But double
attacks by bishops require certain conditions
that often have a distinctive look.
A bishop fork most often occurs when your
opponent has two pieces on the same diagonal
with nothing between them; when the bishop
moves into position, the three pieces all are in
a line (the position diagrammed in skeletal
form in the previous frame). It therefore is
important to train your eyes to spot any two
enemy pieces on the same diagonal—
especially if there isn’t anything between
them, but even if there is. This is a good habit
for other reasons as well: pieces on the same
diagonal may also be subject to a fork by your
queen, or may be prey to a pin or skewer
(possibilities considered elsewhere). The
same goes for enemy pieces lined up on the
same rank or file: they may be forked by one
of your rooks, as we will see in another chapter; sometimes they may be forked by a
bishop, as we will see in a moment; and they
may also be subject to a pin or skewer. Diagonals will receive a lot of attention in this
chapter because that is where bishops travel,
but the general point is that pieces on a line of
any type are important to spot.
There is another type of bishop fork that looks
different and can occur when your opponent
has two pieces on intersecting diagonals.
When the fork is executed the pieces are arranged not on a line but in a triangle. A fork
of this kind almost always results from a capture by the bishop on the square that forms its
corner of the triangle; before the capture, the
bishop was aimed at one of the pieces targeted by the fork, but an enemy piece blocked
the bishop’s path to the target (it might be a
pawn, as in the diagram to the left where
White is about to play the fork Bxd6). Another way to say this is that before the bishop
captures, there are three enemy pieces in a
triangle, all on squares of the same color; the
bishop captures one of them and forks the
other two. (Again, see the diagram.) These
patterns are important to study because to the
untrained eye they don't look like the makings
of a fork by a bishop. But they are; they are
poised to be forked in triangular fashion.
The easiest and most common examples of
the triangular pattern arise when two enemy
pieces are on the same file or rank, often the
back rank, with an odd number of squares
between them.
Dg214: White to move
Dg214: Start with the simple case of two
pieces on the back rank separated by one
square—the Black king and rook in the stylized diagram (the diagram is just meant to
illustrate how some different bishop forks can
work; it doesn't call for consideration of what
White should actually play). Black's king and
rook are arranged to be forked—by a knight
at e6, or by a bishop (or queen) at e7. In the
bishop’s case there generally will be an enemy piece already on e7—here, the pawn;
otherwise the bishop would be able to take the
target piece—the rook—without need of a
fork. Now spread the targeted pieces three
squares apart (the White king and c1 rook in
the diagram). Again a fork is indicated—by a
Black knight at e2, or by a bishop or queen at
e3.
And a bishop (or queen) fork again is possible
if the targets are five squares apart, like the
White king and a1 rook. A queen can do the
job by moving in directly—say, from d5 to d4
(imagine the White pawn on d4 rather than
e3); a bishop can do it by taking an enemy
piece sitting on d4, and in this latter case the
enemy pieces again will be arranged as a triangle at the outset. And of course all this can
happen on a vertical file as well as on a horizontal rank. The horizontal formations just are
more common because the pieces start out
arranged that way on the back rank and often
stay there for a while.
The types of triangles just considered are relatively easy to see once you know to look for
them because they have a regular, almost
equilateral appearance. But even the more
oddly-shaped triangles can be found by ha-
bitually looking at what the bishop already
attacks—the line of enemy pieces that lie
ahead of it on any of the diagonals it commands, and what else it can attack by taking
one of them. (See the diagram, where the
Black and White bishops each have a fork via
a pawn capture that creates an unorthodox
triangle.)
wins. Another way to have seen this would be
to ask which Black pieces are loose, which
leads to the rook; the only way White can
attack it is with Bc4, which also checks the
king. A final way would be to just see that the
king and rook are on the same diagonal with
nothing between them. This visual configuration cries out for a double attack by a bishop
(or a queen acting like a bishop).
Dg215: White to move
Dg216: White to move
What does all this mean for practical play? It
means you will want to scan the diagonals on
the board—and the ranks and files, too—for
pieces lined up on them. This is especially
important when one of the pieces is a king.
Also be alert for triangles, and relatedly for
enemy pieces scattered about the board on the
same color squares. A bishop can of course
fork pieces only if they travel on the same
color squares that it does; and almost any two
enemy pieces on squares of the same color
can, in principle, be forked by a bishop from
some other square on the board—“almost”
because there is no way to fork two pieces
next to each other on the same diagonal. The
general point nevertheless is useful, and reinforces a lesson from the chapter on knight
forks: pieces on squares of the same color
tend to be most vulnerable to double attacks
of various kinds. Watch for them.
Dg217: White to move
2.3.2. Bishop Forks One Move Away.
Dg217: What checks does White have with
his bishop? Be4. Does the move attack anything else? Yes, it attacks and wins Black’s
rook, which is loose. This position looks easy,
and it is; but again, absorb the look of it for a
minute. It is important to appreciate the use of
the fianchettoed bishop (on the square in front
of the king) to execute a fork. Later in the
chapter we will see this same position again,
but two moves earlier.
Dg216: What checks can White give with his
bishops? Two: Be8 (resulting in KxB—not
very appealing), and Bc4, which at least is
safe. Does the bishop attack anything else
from c4? Yes, the rook at a2—which White
Dg218: Look for bishop checks and you find
one: Bxc6. Ask what else the move attacks
and you find the loose knight on e4. So Black
moves his king and White wins the knight.
That is the target-based way of seeing the
Now on to some examples.
solution; the pattern-based way would be to
notice the triangular relationship between
Black’s king, knight, and c-pawn, all on
White squares. Stare at the diagram; contemplate its appearance.
bishop, the fork only works if the bishop has
protection on d4. It does, from the Black rook
on d8. So Bd4 trades the bishop for White’s
queen. Now try seeing the pattern by scanning
the geometry of White's pieces; it is important
in a position like this to notice right away that
White's king and queen are on the same diagonal. Again, it will help to take away two
types of lessons from these positions: conceptual points (trains of thought that lead to the
forks) and visual patterns that you will be able
to recognize in your games.
2.3.3. Loosening the Forking Square.
Dg218: White to move
Incidentally, what comes next after White
plays 2. BxN? Now his bishop attacks both
rooks—this time on the same diagonal—and
so wins one of them as well. Again, you could
see this by asking what the bishop attacks, or
you could see it by scanning Black’s pieces
for promising patterns and noticing that
Black’s two rooks are on the same diagonal,
just waiting to be forked if White can take the
Black knight with his bishop. He can best do
that by advancing on the knight in a way that
also gives check (i.e., with Bxc6+), thus requiring Black to address the threat to his king
rather than defuse the coming fork of the two
rooks.
Dg219: Black to move
Dg219: Inspect for checks Black can give
with his bishop; this turns up Bd4. Does the
move attack anything else? Yes, White's
queen at b6. Since the queen can attack the
Dg220: Black to move
Dg220: What checks does Black’s bishop
have? Bd4. Look to see what else the move
does and note that it attacks the loose rook at
a7. So there is a potential bishop fork at d4—
but the square is protected by the knight at b3.
So of course you look to take the knight and
thus play RxN. The response a2xR follows,
and after the exchange d4 has become a loose
square. Black safely plays Bd4+, White’s
king moves, and Black takes the rook. All this
is familiar from our prior work on double
attacks. But notice the different visual look of
this position; see the White rook and king
stretched out along the same diagonal, and
realize that this signals a forking possibility.
As discussed earlier, a rook often can make a
good target for a bishop fork whether it is
protected or not. Here, however, the fork
worked only because the rook was unprotected. The reason, which is common, is that
the fork required a sacrifice by Black in the
first place—here, a sacrifice of his rook for a
knight. To justify that sacrifice, the fork that it
creates has to make a big score. Taking a rook
for nothing makes it worthwhile. Taking a
rook that had protection, and then losing the
bishop, would have made the combination a
wash.
Dg222: What visual pattern do you see?
Black’s king and knight on the same diagonal;
this suggests that conditions may be right for
a fork. Bd5+ almost does it, but the rook at d3
protects both the forking square and the targeted knight. White can’t capture the rook, so
he proceeds by asking if he might capture the
knight with some other piece, thus attracting
the rook onto the knight’s square when it recaptures and leaving it loose. He can. 1. RxN,
RxR both loosens the forking square and creates a loose target. Now Bd5+ forks and wins
the rook.
2.3.4. Loosening the Target and Forking
Square.
Dg221: White to move
Dg221: Almost the same. White has a check
with his bishop in Bxd5. The move also attacks the loose rook at a2. The d5 pawn is
protected by the knight at b6, but the knight
can be captured with RxN, a7xR, leaving the
forking square loose. White plays 2. Bxd5+,
Kh8, and then 3. BxR. That is how the position comes apart under interrogation about its
targets, but notice as well that visually it is
almost identical to the previous one; the only
difference is that a Black pawn lies between
the king and rook. It is important not to let an
obstruction like that prevent you from seeing
that the king and rook are on the same diagonal. Look through the pawn as you trace the
lines on the board with your eyes.
We now consider a common pattern that is a
variation on the theme just considered. Often
a possible bishop fork has a pair of problems:
the piece it would target is protected, and the
piece also guards the forking square. This
most frequently happens when the target of
the potential fork is a bishop or pawn. The
solution then is to perform an exchange with
one of your other pieces that trades the bishop
or pawn for a better target—one that is loose
and that cannot fire back at your own bishop
when it executes the fork.
Dg223: White to move
Dg222: White to move
Dg223: An illustration will make the point
clearer. Recall our current drill: look for any
enemy pieces lined up on the same diagonal,
and especially for pieces lined up on the same
diagonal as the king. Here Black’s king and
bishop are aligned. The bishop won’t work as
a target for a bishop fork; it is protected and it
can attack the forking square. But seeing the
geometry still can provide an idea to motivate
your examination of forcing moves. A common way to deal with an unsuitable target is
by capturing it with another piece, allowing a
recapture, and then executing the fork against
its replacement. So the solution here is the
preliminary exchange RxB. If Black responds
with RxR, now the bishop has been replaced
with a rook that is loose and that cannot guard
the forking square. Bc5+ wins back the rook
and nets a bishop.
Dg225: Here is a position nearly the same as
the previous ones, but involving a triangular
pattern rather than a single diagonal. Still, ask
the same questions; get comparable answers.
Black plays 1. …RxB, 2. RxR, Bxf4+, forking Black's king and rook and netting a piece
and a pawn.
Dg226: White to move
Dg224: White to move
Dg224: The initial visual clue here is about
the same as in the previous problem; see it, or
simply ask what checks White’s bishop has.
There is Bg6, attacking nothing else, and Bc6,
attacking the bishop at b7—an unsuitable
target that also guards the forking square. So
again White exchanges the unsuitable target
for a suitable one by capturing it and inviting
recapture by Black: 1. RxB, NxR, and the
bishop has been replaced by a knight that is
loose and that cannot defend c6. Now 2. Bc6+
picks up the knight, winning two pieces for a
rook.
Dg226: The salient visual point is that Black’s
king, bishop, and rook all are lined up on the
same diagonal. There is work to do before this
can be turned into an effective fork, but the
idea that will motivate your inquiry is clear.
Bxc5 attacks the Black rook and aims the
bishop at the Black king. The Black bishop on
e7 is the only obstacle to a winning fork: it
guards the forking square and blocks the line
to the king. As usual, the remedy is an exchange of the bishop for a better target. 1.
RxB, KxR; 2. Bxc5+ forks king and rook and
again wins a piece and a pawn.
Dg227: Black to move
Dg225: Black to move
Dg227: What checks does Black have with
his bishop? BxN+. The move also attacks a
pawn at b4, and a protected one at that; and
the pawn guards the square anyway, along
with the White rook. So there is nothing here
yet, but if you at least see this much you will
have the idea in hand and can use standard
techniques to build a little combination out of
it. Black takes the pawn with another piece: 1.
…Rxb4; and now if 2. RxR, Black plays
BxN+ and wins back the rook with the gain of
a piece and a pawn. (In the actual game White
replied 2. Ra5, BxN+; 3. RxB; Rf4+ (another
double attack, this time against White's king
and f-pawn); 4. Ke3, Rxf5 and Black was two
pawns ahead.)
2.3.5. Moving the King into Position, etc.
As you no doubt are noticing, the tools required to create bishop forks are the same
used to create many forks by the queen and
some by the knight. Here, as in those other
cases, there often may be a forking square that
needs to be loosened; the techniques for loosening it—e.g., a preliminary capture of the
piece that currently sits on the square, or of
the guardian of it—are the same regardless of
whether the goal is to put a bishop, queen, or
knight on the square. It would be possible just
to leave it at that, but for the sake of building
pattern recognition skills it will be worthwhile
to see at least a few examples of how these
processes look in the context of double attacks by the bishop.
And in any event the thought process is not
quite the same. In this section we consider
cases where the bishop has no way to give a
check, but where with some work you can
build a fork that involves an attack on the
enemy king at one end. The crucial initial
question is how you would realize there is an
opportunity for such fork-building in the first
place. If the bishop has no checks, what
would cause you to try to create a fork involving one? The answer, of course, is that you
look for any other pieces the bishop can
threaten that would form good targets for a
double attack; having found one, you then go
to work to create a check at the other end. We
saw that in the queen’s case this generally
meant that you had to find or create a loose
piece to attack, because a queen can’t afford
to attack anything that is protected. One of the
pleasures of attacking with the bishop, however, is that its list of good targets is longer;
thus these positions require you to start by
considering carefully whether the bishop can
threaten any loose pieces, or rooks, or queens.
These problems may require you to keep developing some new habits. If you are not an
experienced player you probably are accustomed to asking what pieces your bishop (or
your other pieces) can capture on the next
move, but not what pieces your bishop can
threaten on the next move (and thus capture in
two moves). But that is the important question
here, as it often was in the earlier chapters. In
the bishop’s case the examination of possible
threats is pretty easy because the movements
the piece makes are limited and easy to follow. It also simplifies the task to remember
that any possible targets of the bishop must sit
on the same color square that it does.
The visual patterns we used to set the analytical process in motion in the last section may
be a little less helpful here, because at the
beginning of these positions the king and the
target piece tend not to be on the same diagonal or triangle. You still may be able to see
that the king almost is aligned with another
piece, and so have the idea of moving them
into alignment with each other. Even if you
don’t see that, the key patterns emerge here
after an initial exchange or two; and much the
point of mastering the relevant visual patterns
is to be able to recognize them not just at the
beginning of a position but as they emerge
after you have imagined initial forcing moves
and responses in your mind’s eye.
Dg228: White to move
Turning to the position on Dg228: What
Black pieces can White’s bishop attack? (We
do not just ask what Black pieces are loose,
because a more valuable enemy piece may be
a good target for a bishop even if it is protected.) Answer: it can attack the rook by
moving to d2 or d4. Threatening a rook is a
nice start, but becomes really interesting only
if it also is accompanied by another threat in a
different direction—i.e., if it is part of a fork.
So what other threat can be engineered into
existence? Bd4 aims the bishop in the king’s
general direction; if the king could be moved
onto the same diagonal as the rook, White
would have a double attack. What checks
does White have that force the king to move?
Only one: f4-f5+. Carefully consider Black’s
options in response. He can move the king to
e5 or f6; there is nothing else. Either move
puts the king into the path of the White bishop
once it moves to d4+; and after the king then
moves again, BxR takes the rook. Black can
recapture with his other rook, but White wins
the exchange.
Dg229: White to move
Dg229: What Black pieces can White’s bishops attack? (Not what can they capture, but
what can they threaten by moving.) Bf5 attacks the rook at e4. (The other rook is loose,
but the dark-squared bishop can’t reach any
squares from which to attack it.) The lightsquared bishop would have a fork if Black’s
king somehow could be moved onto g6. The
simplest way to move the king is with checks,
and White has two. The first is Rf5, but this
will not necessarily achieve the desired end
(Black can play Kh6 or Kg6; Kg6 sets up a
fork, but White can’t pull the trigger because
his own rook is then on the square that his
bishop needs). White’s other check is Bc1+—
another study in the importance of remembering backward moves. Black would have to
either move the king to g6, thus walking into
the fork Bf5+ and losing the rook; or he could
try his only interposition: Re3, blocking the
check. But then White plays BxR and wins
the exchange. So 1. Bc1+ wins regardless.
White starts out ahead in that he has two
pieces for Black’s rook; after winning the
exchange he is ahead by a whole piece.
Dg230: White to move
Dg230: What pieces can White’s bishop
threaten? Bxd5 attacks the rook on a8 and
aims the bishop at Black's king. Or a visual
way to assess the position is that it is a classic
example of a king-and-rook triangle that lends
itself to a fork at d5. Either way you look at it,
the trouble is that the pawn on e6 blocks the
way to the king and guards d5 as well. The
point is clear: the pawn must be vacated from
that square. Moving an enemy pawn off a
square is best done by capturing something it
protects. Here it protects the knight at f5; so 1.
RxN, 2. e6xR does the trick. Now Bxd5+
safely attacks king and rook, picking up the
latter next move and netting a piece.
Dg231: White to move
Dg231: White’s bishop can’t give a check and
can’t safely threaten anything. But it can
make a capture: Bxd5. Don’t just reason that
it loses a piece to BxB; look for patterns that
might form the basis of a tactical idea. On d5
the bishop would be aimed at Black’s king
and rook, though its path to each piece is
blocked. Again, a visual way to see the tactical possibility is to note the classic king-androok triangle that would lend itself to a fork at
d5 if only the white rook and black bishop
could be cleared out of the way. Pick either
obstacle and think about how to get rid of it.
If you start with the rook at b7, you need it to
vacate its square in a violent fashion that requires a response and gives the enemy no
time to regroup. The obvious solution is a
capture: RxB, to which Black replies KxR,
which takes care of both problems. Now
Bxd5+ wins the rook. Or start your thinking
with the Black bishop at f7. The natural way
to get rid of it is by capturing it; and the only
way to do so is with RxB, which again leads
to KxR and the bishop fork from d5.
Black king somehow could be moved onto the
diagonal leading away from the rook toward
d8. The next step is to experiment with whatever (other) checks White has available.
Dg232: White to move
Dg233: White to move
Dg232: This one is a step up in difficulty.
What can White’s bishop do? Its checks don't
seem to lead anywhere, but there are other
attacking possibilities to consider as well:
Bg5, attacking the Black bishop (barely worth
noticing because it's a useless target); Bd2,
attacking the Black rook; and Bxb6, attacking
rook and bishop. This last move has the appealing look of a double attack, but again the
bishop is an unsuitable target. This may be as
far as you can go with initial reconnaissance;
what you know is that (a) White has no double attack as yet; (b) if he is to make one, the
most plausible place for it probably would be
b6; and (c) a fork there might be doable if the
Dg233: What can White attack with his
bishop? Be4 attacks a knight, which might
make a good start for a double attack if the
knight were loose; but it is protected by the
rook at d8. Nor would the bishop then be attacking anything else. Still, the sight of the
bishop attacking an enemy piece while also
aimed at h7 should stimulate your imagination. If a loose piece could be substituted for
the knight, and if the king could be pushed
onto h7 as it was in some earlier problems,
White would have a fork. So experiment a
little with those possibilities.
The only check White can give with another
piece is Rd1+. How would Black respond? If
he plays Ke6, White would be able to play
RxB; the Black bishop would be the victim of
a skewer. To avoid this fate Black would need
to move the king not to e6 but to a square
where it can protect the bishop: either Kc7 or
Ke7. Then what? Again, the pattern that
would then exist probably would be easy
enough to recognize if you encountered it as
an initial matter: With Bxb6 White has a double attack against the a5 rook and against either the bishop on d8 (if Black moved his
king to e7) or against the king itself (if it was
moved to c7). The fork still isn't quite there;
White needs to perfect it by substituting the
Black king for the Black bishop with RxB, to
which Black responds KxR. Now Bxb6 at last
wins the rook.
When a target is protected, one way to loosen
it is to take it with another piece and allow for
a recapture; here, 1. NxN, RxN and White has
half of a bishop fork in place. Next White
turns to any checks that would force the king
onto h7 and finds Ra8 (remember that the
Black rook no longer would be on d8). After
2. Ra8+, Kh7, White plays 3. Be4+ and wins
the rook.
This is a position we already saw early in the
chapter, where it was advanced to its last step;
the point of repeating it here is to enable you
to see what the same fork looks like a couple
of moves away. Notice, too, that the sequence
succeeds here only in the move order described; trying to move the king first, and then
performing the exchange of knight for rook,
would not have worked. So remember to look
for your checks before and after you imagine
captures you can make.
Dg234: What can Black’s bishop threaten?
The two White pieces on light squares: the
rook and knight, but not at the same time (the
possible attacking moves are Be6, Be4, and
Bxc2).
winning the rook without any need to force
White’s king into a more vulnerable position.
The lesson is to take notice if a bishop can
attack both an enemy piece and a square next
to the king. It may be that a preliminary exchange will allow you to move the king and
so then check with the bishop move, or that
aiming the bishop at that square will itself
produce a mating threat that works just as
well as a check as an anchor for the fork.
2.3.6. Bishop Forks of the King and Queen.
When your bishop makes the queen the target
of a double attack, you can't generally count
on a fork or other nifty maneuver to save the
day when your opponent replies QxB. So
typically a fork against the queen only works
if the bishop has protection. Here are a few
examples of how this looks.
Dg235: In the position on the diagram, White
looks at his checks and sees that Qd8 forces
Black's king to h7. He looks for his next
check and finds Bf5, which forks Black's king
and queen—but fails because Black simply
plays QxB; by then, White's queen no longer
is on the fifth rank to supply protection.
Dg234: Black to move
Attacking the rook with Be4 has the interesting result of also attacking a square—h1—
next to White’s king. In the previous problem
this was exploited by forcing the enemy king
onto the targeted square with a check. Here
there is a different possibility. Consider the
White king and the constraints on its movements. The back rank is owned by Black’s
rook. If the bishop were attacking h1, Rh1
would be mate. So no setup is needed. Be4
threatens the rook and threatens Rh1#, thus
Dg235: White to move
The fork would work fine if only the bishop
had a guard. Ah, but White can have it both
ways by giving the check with a different
piece: Rb8. This likewise forces Black’s king
and queen onto the same diagonal, and this
time White wins with Bf5+.
Notice that the problem starts with Black
threatening checkmate by playing Qxg2. In
the face of this threat it would be natural for
White to think defensively, but as we know,
sometimes the best defense is a good offense.
amounts to nothing yet because the bishop
wouldn’t be protected against QxB and because it has nothing else to attack at the same
time. But the king is not far away, and if it
could be moved onto h1 Black would have a
classic triangular fork with BxN. Consider
any checks Black can give and how they
might change the board. There's Bb6xf2,
which loses the piece, and then the more interesting Qxg3+. Can White reply f2xQ? No,
because the f2 pawn is pinned. White therefore would have to play Kh1. Now BxN attacks both king and queen—and thanks to the
previous move by the queen, the bishop now
would have protection at f3. So White responds to BxN with QxB, and Black replies
with QxQ+.
Dg236: White to move
Dg236: We start with an open diagonal to
Black's king, and a Black piece — the bishop
— on the same line. Now look for checks
White can give with his own bishop, and find
Be5+. If the Black bishop could be swapped
out for a better target, White would have a
nice double attack. So capture Black's bishop
with another piece: 1. RxB, QxR and now the
scene is set for Be5+, forking Black’s king
and queen. The point of seeing the position
here is that since the queen is the target,
White’s bishop needs protection on the forking square; it gets it from the f4 pawn. One of
the many nice things about having a pawn in
or near the center is that it can provide a protective anchor for a piece delivering a fork.
And what then? White has to move his king to
h2. (Moving it to g1 is also a possibility, but
eventually leads to mate for Black.) Black
keeps the offensive pressure on with Bxf2.
White has no appetizing options in reply.
Black threatens to mate with Qg3+ followed
by Qxh3#; White can prevent this by using
his rook to take the bishop on f2 or by playing
Rg1, but either way he loses the exchange.
Seeing the initial forking idea here was the
key point, but playing through the rest of the
sequence in your mind’s eye will be a useful
exercise in extending your range of vision.
In summary, then, here is the most likely sequence: 1 …Qxg3+; 2. Kh1, Bxf3+; 3. QxB,
QxQ+; 4. Kh2, Bxf2; 5. Rg1, Bxg1+; 6. RxB.
Dg237: Black to move
Dg238: White to move
Dg237: This time Black has no bishop checks
(except the useless Bxf2+), so just ask what
else his bishops can attack. You see then that
BxN threatens White’s queen. The threat
Dg238: What checks does White’s bishop
have? Bxe6. Does the move attack anything
else? Yes, the bishop at d7, which is an un-
suitable target. Or see it visually: we have a
classic triangle between Black’s king, queen,
and e6 pawn; the bishop can be understood as
an inadequate target or as an obstruction. Either way, the natural next step for White is to
capture the bishop with another piece — as
with RxB. Then if Black recaptures with QxR
the board is prepared for Bxe6, now with
Black’s queen as the target. Like the bishop
that it replaced, the queen is a problematic
target because it can fight back against the
forking piece; but unlike the bishop, the
queen’s value is enormous. So the fork works
as long as White’s bishop has protection when
it delivers the fork. It does; it will be guarded
by the White queen. Play therefore goes 1.
RxB, QxR; 2. Bxe6+, QxB; 3. QxQ+, and
now White has won a queen, a bishop, and a
pawn in return for a rook and a bishop.
by taking whatever the pawn protects and
pursuing the consequences. Again, trains of
thought like this will be the focus of our later
study of pins.)
Dg239: A quick look at checks White can
give with his bishop turns up Bxd6. Does the
move attack anything else? Yes, the knight at
e5. The knight is protected by Black’s queen
(though also attacked once already by White’s
knight on d3), which also protects the d6
pawn.
Dg240: Black to move
Dg239: White to move
So play with exchanges White can initiate and
with the move orders made possible by the
threat White already has against e5. A natural
possibility to consider is 1. NxN, QxN. This
upgrades the target of the fork; it also leaves
behind an open line of protection from the
White queen to the forking square. Thus Bxd6
now forks king and queen. (Another way to
see the idea here is to notice that the Black
pawn on d6 is pinned to its king by the bishop
at a3, and to look for ways to exploit the pin
2.3.7. Bishop Forks of Other Pieces.
Dg240: What checks can Black’s bishop inflict? None, of course, not least because the
bishop is on a light square and the king is on a
dark one. But the king is just the best anchor
for a fork, not the only one; you really are
looking for a square where your bishop might
be able to attack any two vulnerabilities at the
same time. Here the bishop can move to c6
and attack White’s b7 knight and h1 rook,
both of which are on the same light-squared
diagonal and both of which are loose. Black
wins the knight.
If you step back from the board and look for
visual patterns, the alignment of White's
knight and rook with nothing between them
should be conspicuous. Use these studies to
gain the habit of spotting enemy pieces like
these that are on the same line (not to mention
loose).
Dg241: Black has no bishop checks (Bc5 obviously would be unsafe, but it's irrelevant
because the bishop is pinned). Think more
broadly about threats he might make with the
piece. White’s bishop, knight, rook, and
queen all are on light squares, and so is
Black’s e4 bishop. The queen and rook are on
a common diagonal and so can be attacked
with Bc6. When a bishop forks the enemy
queen it requires protection, as we know; it
has the needed cover here from its own queen
at c1.
Dg241: Black to move
Black thus wins the exchange: 1. …Bc6; 2.
RxBf8+, RxR. Or perhaps he wins a queen for
a rook and a bishop, the result if play goes as
follows: 1. …Bc6; 2. QxB, QxQ; 3. RxR, Kg7
(protecting the bishop). (Or instead 2. RxR,
BxQ; 3. RxB+—same basic result.)
Dg242: Black is confronted with a fork by
White’s bishop; he is about to lose the exchange to BxRf8. But instead of reaching to
move the knight, think about Black's own
offensive options.
Dg242: Black to move
Again he has no checks, but ask anyway what
else his pieces can threaten. In this case his
dark-squared bishop can fork the White
pieces also on dark squares: the knight and
bishop. (Step back and scan the diagonals and
other lines for pieces lined up on them.) The
knight is loose, but of course the bishop is
protected and anyway is an unsuitable target
for a bishop fork. We handle this in the usual
way: Black takes the bishop with RxB, to
which White replies RxR. Now Be5 picks up
the knight next move, netting two minor
pieces for a rook.
Or perhaps things play out differently (the
following sequence will take a bit of patience
to follow): White can reply to 2. ...Be5 by
leaving his rook on d6 and instead playing
Nf5, taking his knight out of the fork and using it to give the rook protection. If Black
replies e6xN, notice that White now has the
rook fork Rd5—attacking the loose Black
pieces that would then be on c5 (the knight)
and e5 (the bishop). The pawn on e6 was
guarding against this danger before it captured (in this variation) on f5. So instead of
e6xN Black would want to respond to Nf5
with RxN. Now White has the recapture
e4xR, but then Black has BxRd6, with the
fork at last paying off. He ends up with two
minor pieces against Black’s rook.
Now for extra credit, do you realize that the
success of Black's fork here depends on his
knight at c5 and his pawns on b7 and e6?
Let's consider why. First, once White is
forked he almost can move his rook both out
of harm’s way and into position to protect his
knight by playing Rd3. If this move were feasible the fork would be foiled; it is not feasible only because d3 is attacked by Black’s
knight. This pattern nevertheless illustrates
once again the extra difficulties created by
double attacks against two ordinary pieces
rather than the king: you have to ask what
mischief either of them could make in breaking out of the fork.
And then notice, too, that the aforementioned
Black knight on c5 is loose. This makes it a
vulnerable target, so you need to worry that
White might break out of the fork and make a
counterattack against the knight. This almost
is possible; once White’s rook is baited onto
d6, it nearly can break out of Black's subsequent bishop fork with Rc6 or Rd5, threatening the knight. But not quite, because both of
those squares are guarded by Black pawns.
The lesson: we know that when you fork two
enemy pieces (not the king), you need to ask
whether one of those pieces might spoil the
fork by rushing to the defense of the other;
but consider as well whether one of the pieces
in the fork might go off and make a threat
against you elsewhere.
Dg244: Black to move
Dg243: White to move
Dg243: White has a bishop check with Bd6+.
How would Black respond? Probably with
Ka8. Whenever you imagine a move that
would force your opponent to move—and
especially a move that would force him to
move his king—imagine the position that
would result and interrogate it with the same
questions you might ask if it were the board in
front of you. What Black pieces would be
loose? What pieces are aligned? Black's
queen and rook—which indeed are already
aligned from the start, and would then be
forkable with Bc7. Since the queen is one of
the targets, naturally we look to make sure the
bishop will have protection. It will, from the
rook at c4.
This description suggests how looking at
every check might have led to the fork. Another way to see it, though, is to step back and
notice first Black’s queen and rook on the
same diagonal, especially since they have no
pieces between them. That pattern is a set up
for a double attack by the bishop. The question then becomes whether you might maneuver the bishop into position, since it cannot
get to c7 directly. When you want to make a
preliminary move without giving your opponent time to defend against the fork you are
creating, the preliminary move has to be forcing. A check is best. Conveniently, White’s
bishop can give a check on the way to c7 by
stopping first at d6.
Dg244: The queenside cluster of White’s
pieces looks knotty, but there is nothing difficult about it if you ask the right questions. We
are focusing on attacking ideas with bishops,
and for Black there is just one: BxN, forking
White’s bishop and queen—a small triangle.
Of course the White bishop first needs to be
traded in for a better target through capture by
another Black piece; hence 1…. RxB; 2. RxR
and now BxN forks White’s rook and queen.
Targeting the White queen works because
Black has protection from its own queen at
c4.
Are you satisfied with this? You should not
be. Remember that when you fork two pieces
that aren’t the king, one of them can move to
protect the other. So think especially carefully
about what your opponent’s best move will be
in reply. Here White can respond to the fork
with Qc1, protecting the rook. The sequence
still would be profitable since Black would
have picked up the knight on c3, but keep
pushing for ways to go farther; after White’s
queen moves to c1, rethink the board. White’s
rook is attacked once and defended once. If
Black could add his queen to the attack
against the rook then on b2, he would have it.
He needs a way to do that without giving
White time to move the rook out of danger.
He therefore maneuvers the queen into position with a time-consuming (for White)
check: Qd4+. (This is safe because we're assuming that White's queen has moved to c1.)
White has to move his king; and now BxR
wins the rook at no cost because Black’s
queen protects against a recapture. (White’s
better option after the forking move BxN is to
play Qxd6, at least taking a pawn rather than
making futile efforts to save his rook.)
Incidentally, at the outset of the position
Black might be tempted to play BxN; once
White recaptures on c3 with his bishop, the
way is clear for Black to take White’s loose
rook on b1 with RxR+. But the idea fails because that recapture by White—BxBc3—is a
check. You cannot be too alert to possible
checks your opponent can give in the midst of
a plan you are devising. A check has the
power to stop a tactical sequence in its tracks.
Dg246: White to move
Dg245: White to move
Dg245: This time start by looking for pairs of
Black pieces that might be vulnerable to a
bishop fork. How? Look for pieces on squares
of the same color, or on the same or intersecting diagonals. The c5 knight and e7 bishop
are in the right pattern, but there is no way to
exchange the bishop for a suitable target. But
now what about the pieces on light squares?
Black’s rooks are on a6 and a8—on the same
file, one square apart, and arranged for a
bishop fork with Bxb7. White’s light-squared
bishop is aimed the right way; the only trouble is that White’s own pawn is in the way at
d5. If it is going to move, first the Black pawn
in front it has to be moved. You move a pawn
by capturing something it protects; here it
protects the knight at c5, so 1. NxN (capture
with the least valuable piece you can), leading
to 1. …d6xN, clears Black’s d-pawn onto the
c-file. Now White moves his own pawn forward to d6, making a threat against Black’s
bishop that requires a time-consuming response. After the bishop moves (presumably
with Bxd6), White is able to play Bxb7, forking both Black rooks and winning the exchange next move.
Dg246: A position like this is best approached
visually. What do you see? Both of Black’s
knights, his rook, and a pawn are lined up on
the same light-squared diagonal. White’s
light-squared bishop can, in principle, intervene at c6. Nothing can be done with this yet,
because pieces are in the way, squares and
pieces are guarded, etc. The point is just to
see the idea. Then you can play with exchanges, carefully visualizing their consequences to see if they help clear the obstructions out of the way and improve the targets.
White has two possible captures that might
help the b5 bishop to make trouble: NxNc6
and NxNe4. In effect those possible captures
are options you hold to make the board look
different. If you play NxNe4, Black will play
RxN, and now the board will be changed;
likewise if you then play NxNc6 and Black
replies b7xN. (He can’t play d7xN because
after White moved his d4 knight, Black’s dpawn became pinned to his queen. Black’s
rook no longer will be protecting the queen,
either, having moved to e4 to recapture during
the first sequence.) Notice how two exchanges White can initiate so change the look
of the board even if they don’t turn any profits
themselves.
And then what would be possible? If the position were set in front of you the answer would
be obvious: Bxc6, forking the rooks and winning the exchange. (Black plays RxBe3, and
White recaptures RxR.)
Lesson: move order matters. There are a number of ways to look at White’s captures in the
wrong order here and find nothing; capture
with the wrong knight first and the sequence
is ruined.
2.3.8. Playing Defective Bishop Forks.
We conclude with a series of positions where
a potential bishop fork looks unplayable because the forking square is guarded—but
where the fork nevertheless is the winning
move because checkmate or some other decisive consequence results if the forking piece
is taken. We have seen that a parallel logic
can make seemingly bad knight forks quite
productive; naturally the same is true of any
other sort of fork that may not look feasible at
first.
Dg247: A first example of the idea. Look for
a visual pattern; see that White has his king,
rook, and d4 pawn arranged in a classic triangle that calls for consideration of a queen or
(here) bishop fork by Black. (You could also
just ask what checks Black’s bishop has; the
only answer is Bxd4.) Bxd4+ thus has the
potential to take the rook at a1, but the d4
pawn is protected by White’s knight.
Dg248: Black to move
Dg248: Think visually. White’s king and a6
rook are on the same diagonal, inviting Bc4+.
Or again you could see this by asking what
checks Black can give with his bishop and
seeing that one of them—Bc4—also attacks a
rook. Either way the problem is that White
protects c4 with his other rook. There is no
immediate way to get rid of the rook, but before moving on ask what happens if Black
goes through with the fork and White plays
RxB. What checks could Black then play?
Rb8-b1, which is checkmate (after White uselessly interposes his rook from c4 to c1). So
Bc4+ wins a rook despite the apparent protection of c4 by White’s rook, which really can’t
afford to move. The tipoff here is Black’s
other rook on the second rank; it traps
White’s king on the first rank, making it vulnerable to a back-rank mate if the rook on c1
leaves its post.
Dg247: Black to move
There's no good way to get rid of the knight,
but don't stop there. Imagine the sequence
failing and ask what it would make possible.
It then goes 1. …Bxd4+, 2. NxB. What lines
would then be open? What checks would
Black then have? The answer is Qe1—mate.
So the bi-shop fork at d4 works after all, winning a rook and a pawn.
Dg249: White to move
Dg249: Whether you look for Black pieces on
common diagonals or ask whether White has
a way to attack two pieces at once, the same
answer appears: Bd7. The move seems pointless because Black just plays QxB. But ask
what checks White then would have. There
are four: Qe8, Qe7, and Qb4, none of which
are new and none of which works; and QxR,
which is new (well, the move itself isn't new,
but it didn't give check in the initial position),
and which leads to checkmate a move later.
(If Black blocks the check with Qe8, White
has QxQ# with protection from the rook on
e1.) Since Black can’t afford that, the initial
fork Bd7 actually works well, picking up the
knight.
The key to seeing this, as ever, is to be thorough in examining checks and their consequences—not only on the board in front of
you but on the board as it would look after
whatever forcing moves you can imagine.
You likewise want to be alert to how any recaptures you can force would open lines or
leave things loose. Here the Black queen’s
movement off the back rank opens a line to
the king from a8, and turns out to be fatal.
It is good to see the bishop fork in this position, but there is another route to a similar
result that is worth seeing as well. All sorts of
possibilities spring up once you realize that
Black’s queen needs to stay on the back rank
to prevent White from mating with QxR; for
this means the Black queen itself is vulnerable
to attack. White therefore can play Bxa6, putting Black in a pickle. If he plays QxB, he
promptly gets mated; so he moves his queen
to e8, where it is safe and continues to protect
the rook on a8—but now he has left his knight
loose, so White plays QxN. Black’s queen
was overworked, a theme we have seen before
and will study in detail later. There is more
than one way to take advantage of such a
situation, as this analysis shows.
Dg250: White to move
Dg250: You can see the idea here visually by
noting the dark-squared triangle between
Black’s rook, king, and e-pawn, or by asking
what checks White can give with his bishop
and what else he can attack at the same time.
Either way White would like to play Bxe5 but
seemingly is prevented from doing so by the
threat of NxB. Ah, but what if that threat is
carried out? Lines would be opened by the
moves of White’s bishop and Black’s knight.
White would have a new check with Rc7 — a
rook fork which also attacks Black’s queen. If
Black moves his king or blocks the check by
moving his knight or bishop to d7, White
plays RxQ. If Black plays QxR, then White
plays QxQ+, and then (after Black moves his
king) QxR.
Dg251: White’s rooks are arranged on the
same diagonal and thus could be forked with
Bxb2. But that won’t do because White is on
the verge of mate with Qa8, Qxc7, or Ra8.
Black’s next move therefore needs to be a
check that forces White's reply. He has four.
Two can be dismissed quickly: Rd1 just loses
the rook and Qxg2 just loses the queen.
Dg251: Black to move
A third check, Bxh2, is a little more interesting, as White wouldn't particularly want to
reply KxB; for Black would then have the
queen fork Qh6+, compelling White to trade
queens to get out of it. Instead White would
move his king to f1. Now Black has the queen
fork Qxc1, again forking White's king and
queen—but this time without protection. So
White plays QxQ. Black has taken a pawn
and a rook but has given up his queen for the
sake of disrupting the mate threat. So all this
is possible, and might even seem an appealing
reprieve from execution—but hold! For there
is yet one more initial check for Black to consider.
Starting with this last remaining check,
QxR+, turns out to be most interesting of all.
White replies QxQ, letting go of his mate
threat. Now what would be possible? White’s
queen and rook would be on the same diagonal, so Black toys again with Bxb2. Of course
White could just play QxB. But again you
consider what lines would have been opened
by all this and what checks Black would then
be able to inflict. As for open lines, Black’s
bishop would have moved off of the e-file,
creating a new path for the rook on e8; now
the rook could move to e1—which would be
mate! So in reply to the forking move White
is obliged to move his queen and let his rook
on a3 be taken by Black’s bishop. Black
emerges with two rooks and a pawn in exchange for a queen—a slight material gain;
and meanwhile he has obliterated White’s
mating threat and reached a winning position.
It's yet another study in the importance of
examining every possible check, both on the
current board and on the board as it would
look after an exchange or two.
2.3.9. Strategic Implications.
A bishop’s power—its potential to execute
double attacks and its usefulness in other
ways—generally depends on whether it has
open lines on which to move. A bishop placed
on one of the long diagonals with nothing in
its way is a mighty force on the board; a
bishop blocked by its own pawns has relatively little use. It might seem to follow from
this that you should try to maneuver your
bishops onto open diagonals, and indeed that
generally is good practice. But there also are
other, subtler steps you can take to increase
the power of your bishops and limit the power
of your opponent’s.
Dg252:
Dg252: The first thing to understand is that at
any given moment your two bishops may differ greatly in their attacking potential. One
travels on the dark squares, the other on the
light squares. Usually one of them turns out to
be more useful than the other, because either
the dark or light squares in the middle of the
board—but not both—will be open. “Open,”
here, means unoccupied by pawns. Notice
that your pawns frequently are set up on
squares of the same color; that is how they
protect each other. If your pawns are arranged
on light squares, those squares are “strong”
for you and the dark squares are weak—i.e.,
unprotected by pawns. But it also means that
your dark-squared bishop has room to run and
that your light-squared bishop is likely to be
less useful, at least until the pawn structure
changes. Thus we speak of a bishop as “good”
if it travels on squares unobstructed by your
own pawns; a bishop is “bad” if it travels on
the same colored squares your pawns do. In
the skeletal diagram to the left, both bishops
are fianchettoed (i.e., White has developed
them to the squares in front of his knights’
original positions). The dark squares are very
strong for White because he controls them so
thoroughly with his pawns. But a side effect is
that the bishop on b2, which travels on the
dark squares, is bad; the bishop on g2 is good.
We focus on the pawns near the center because the best diagonals pass through the
middle of the board. If you look back at the
studies in this chapter, you will see that the
attacking bishop usually takes advantage of
open paths through the center; it rarely is the
case that there is a center pawn on the same
colored square as the bishop that delivers the
fork. There may be an enemy pawn there that
is captured by the bishop, but there generally
is not an allied pawn that blocks the bishop’s
way. Notice that even one pawn in the middle
can be significant, since it single-handedly
blocks long diagonals in two different directions.
These points have several implications. First
and most obviously, you should think of your
two bishops as quite different pieces, and you
should be much more willing to trade away a
bad bishop than a good one. Second, pawns
and bishops have an intimate relationship.
Think of pawns as pylons that obstruct the
paths of the bishops; every time you move a
pawn you open one diagonal and block another, and this may be the most important
consequence of such a move. Whether lines
are open or closed will matter for your other
pieces as well, of course, but all of the other
pieces have the option of moving back and
forth between light and dark squares if necessary. Bishops cannot, so they are especially
sensitive to pawn placement; moving your
bishop often does less to make it powerful
than moving a pawn out of its way and onto a
different colored square. If that can't be done,
you need to maneuver your bishop outside the
pawn structure. In any event, try regarding
pawn moves as indirect bishop moves.
2.4. The Rook Fork.
2.4.1. Introduction.
Double attacks with the rook are simple
enough to understand, but they also are easily
overlooked because the rook is used so heavily for other more familiar purposes. The suitable targets for a rook fork are the enemy
king, the enemy queen (if the rook has protection), or any loose piece. As a practical matter
the targets of a rook fork almost always include either the king, a loose piece, or both;
this will be the guiding principle behind our
target-based searching. The visual pattern
involved also can be stated simply: a rook can
slide between two pieces on the same rank or
two pieces on the same file.
Dg253: Black to move
This principle is important from a defensive
standpoint as well. If you move a pawn and
the move opens an important diagonal—
especially a diagonal leading toward your
king or another valuable piece—you immediately strengthen the enemy bishop that travels
on that diagonal. Conversely, a pawn move or
exchange can have a powerful effect on the
enemy if it creates an obstacle—or, even better, gridlock—on the squares where his
bishop wants to move. This is particularly
significant if he only has one bishop left.
Locking your pawns with his so that his
bishop can’t get through the center will tend
to make his bishop impotent for so long as the
pawn structure remains in place.
Dg253: The first pattern is more common; in
the skeletal diagram, White’s rook has forked
Black’s king and bishop. The other type of
fork—the double attack against pieces on the
same file—occurs less often and can be a bit
harder to see because the rook then moves
horizontally. The eye is more accustomed to
tracing the rook’s path up and down the
board, rather than from side to side.
Another factor sometimes making rook forks
harder to see is that the enemy targets may
begin with other pieces between them —
yours, his, or both—that have to be cleared
out of the way before the fork can work. The
solution to all these difficulties is to be habitual and thorough in looking for enemy pieces
on the same rank or file, just as you are in
looking for pieces on the same diagonal—and
this regardless of whether there are other
pieces between them. The principle is general:
when you look at lines on the board and
pieces resting on them, follow all the way
through. Don’t let your eyes stop when they
hit an obstacle, because the obstacle may be
removable through an exchange or by other
means; if there are two enemy pieces on the
same line, you want to see that pattern every
time regardless of what lies between them.
Occasions for double attacks by a rook arise
less often than forks with the other pieces we
have considered, and there are only a few
special wrinkles that rooks present. This chapter therefore is shorter than the previous ones.
Dg255: Black to move
Yes, it picks up the loose bishop on b2. Anytime you see the enemy king and another
piece other than a rook on the same rank, an
instinct for a fork should be triggered.
2.4.2. Simple Cases.
Dg256: Black to move
Dg254: White to move
Dg254: Let's begin with some simple rook
forks. Ask traditional questions: What Black
pieces are loose? The knight and rook. What
checks can White give with his rook? Rd1
and Rb7. We seek a match between these possibilities and find it in Rb7+, a move that wins
the knight after Black moves his king. Absorb
the position visually. The spectacle of the
Black king and knight both on the penultimate
rank should immediately suggest tactical possibilities. They aren’t on squares of the same
color, so a double attack by a knight or bishop
won’t work, but they are easy prey for a rook
(or queen).
Dg255: Start by asking what Black can do
with his rook; the first part of the inquiry is
whether it has any checks to give. There is
one: Rc2+. Does the move attack anything
else?
Dg256: What checks can Black give with his
rooks? None. What loose pieces does White
have? Two: the bishop and knight (as usual,
we’re setting pawns to one side), and they are
lying on the same rank—the second, perfect
for a double attack by the rook. As this position and the previous one both show, rook (or
queen) forks on the opponent’s second rank
are a fairly common pattern because pieces
there often are loose: they frequently get no
protection from their fellow rooks, which are
on the first rank, and they can’t be protected
by pawns. Naturally this pattern lends itself to
double attacks by the queen as well; the
rook’s moves, like the bishop’s moves, are a
subset of the moves a queen can make. In any
event, Rd2 wins Black a piece.
Dg257: White has no checks with his rook,
but you want to be equally alert for attacks
you can make against loose pieces. Here the
bishop at h5 is Black's only loose piece, and
the rook can attack it with Rf5.
be a little harder that the other type to see at
first, as noted earlier.
Dg257: White to move
Dg259: White to move
From that square you see the rook also can
attack the knight at e5. The knight is protected
by the Black queen—but it also is already
attacked by the White queen. So the knight is
a classic case of a piece that is threatened
once and protected once and therefore is as
good as loose. If Black moves the bishop after
White plays Rf5, White then plays RxN and
Black dares not recapture lest he lose his
queen to QxQ. White wins a piece.
Dg259: The arrangement of Black’s king and
knight seems almost perfect for a rook fork: a
king and a loose piece on the same rank with
nothing between them always should set off
an alarm, and here White has a rook at the
ready on e1. The problem is that the Black
king guards the forking square, e7, and White
has no way to add protection to that square
that is safe and holds the initiative. Time to
give up? No; time to imagine playing the fork
anyway and asking what would be possible if
it fails. Thus 1. Re7+, KxR; and now Black’s
king has moved, requiring a fresh look at the
resulting position. The king’s move would
have left the bishop on g6 loose; plus the king
would be on e7, a dark square; and the rook at
h8 would be on a dark square as well. White
has a knight in the vicinity, and on a dark
square. You get the picture: 2. NxB+ is a
knight fork that takes the bishop right away
and wins back the rook next move. White
gains a piece with the sequence.
Dg258: Scan for checks with Black’s rooks
and you find two: Rh1 (losing the rook to
KxR), and Rg3. Ask whether Rg3 attacks
anything else, and find the White knight at g5,
which is loose (so you would have been looking for a way to take it anyway). Does Rg3+
lose the rook to f2xR?
Dg258: Black to move
No; the pawn is pinned by Black’s bishop at
c5, so its protection of g3 is illusory. Rg3+
thus wins the knight. This is an example of a
rook fork requiring a horizontal move; it may
This position illustrates a valuable instinct to
develop. The mind recoils initially at the
thought of Re7+ because it loses the rook; the
natural temptation is to abandon the idea and
search for something safer. Cultivate the opposite habit of mind: a willingness to persist,
imagining the loss of the rook and looking for
what would then be possible on the board.
2.4.3. Creating a Target.
Now we turn to studies that involve creating
targets for rook forks, usually by forcing a
preliminary exchange. A common complication is that at the outset of the position the
rook’s path to the forking square is blocked
by the piece that starts the exchange; you
have to be able to see that the exchange not
only creates a good target but also creates an
open line for the rook to reach the key square.
first the e1 rook may look most promising,
but in fact the one on a5 has the more intriguing potential. Follow its path horizontally
through the White knight (at e5) to a square
where the rook can give a check (g5). Again
the question becomes whether the knight can
vacate e5 in a way that creates a target on the
other side of the check. 1. Nxg4 is the answer;
if Black replies NxN, then Black’s knight
ends up loose and 2. Rg5+ wins it after the
king moves. This is almost identical to the
previous position, of course, except that the
rook’s move is horizontal rather than vertical.
Dg260: White to move
Dg260: Begin with the position on the left. A
customary way to start thinking about tactical
opportunities is to ask what captures White
can make and with what consequences. Here
he has just one: Nxb7; the recapture is BxN.
Obviously the exchange is unprofitable on its
face, but imagine the board afterwards and
ask what would then be possible. What loose
pieces would Black have? Both bishops. What
checks would White have? Re1 and Rc7, the
latter as a result of the line opened by the earlier exchange. These facts can be stitched together into a fork: Rc7+ wins the bishop that
would then be on b7.
Dg261: White to move
Dg261: This time try tracing the White rook’s
possible moves through any other pieces,
searching for interesting destinations for it. At
Dg262: White to move
Dg262: What checks can White’s rook give?
Two: Rxf7 and Rd8. The interesting question
about Rd8 is whether a Black piece can be
moved elsewhere onto the back rank and thus
turn that check into a double attack. White
only has one other piece to work with—the
bishop; so try attacking something with it.
Bb5 threatens the Black knight and forces it
to move. Where can it go? Its only safe square
is b8—and once it’s there, Rd8 forks and wins
it.
At several points in our studies we will see
this principle used: an attack on an enemy
knight that forces it to move somewhere useful to you. The thing to remember about
knights is that their range of motion is inherently limited; they never can make it to more
than eight squares, and where (as here) they
are near the edge of the board that number
gets even smaller. This often makes it easy to
figure out where a knight will have to go if
attacked, and thus turns attacks on enemy
knights into very useful forcing moves.
Dg263: White to move
Dg263: What Black pieces are loose? Really
just the bishop on d1; notice how Black’s
knight is protected by the Black rook against
capture by White’s rook. How can White attack the bishop? With Rd3. To make that
move interesting, another loose piece needs to
be lured elsewhere onto the d file. The Black
knight is the only real candidate. Ask what the
knight protects on the d file that you might
attack. Seemingly nothing—but maybe you
can get the knight onto the d6 square by making trouble there with a pawn advance toward
promotion (and the two exchanges that naturally follow): 1. d5-d6, c7xd6; 2. c5xd6,
Nxd6; and now 3. Rd3 forks the bishop and
knight. Black might see this and postpone
Nxd6, first playing RxR; Black is thinking
that after White recaptures with f2xR, Black
can play Nxd6 without fear of being forked.
But White doesn’t reply to RxR by recapturing. He moves his d-pawn to d7 and now it
can’t be stopped from promoting. Black is
better off putting up with the fork after all.
2.4.4. Moving the King into Position.
Dg264: White to move
Dg264: What interesting visual pattern do you
see here? Black pieces lined up on the seventh
rank. The White rook on e1 is poised to attack
at e7, but Black's queen prevents this and isn’t
a feasible target anyway since it can bite.
Still, the idea suggested by the arrangement
of Black’s pieces is the important thing because it guides your thought experiments:
now you have in mind an attack with the rook
and can look for exchanges or other forcing
moves that might make it possible, particularly by replacing the queen with a better target. White has a capture (and check) available
for the purpose: QxQ+, to which Black replies
KxQ. Now comes White's Re7+, forking and
winning the now-loose bishop on f7.
Dg265: Black to move
Dg265: Again, start with the visual pattern,
this time from Black's point of view: White
has two pieces — the two bishops — on the
same rank. The one on a3 is loose. The arrangement suggests a possible fork by the
rook. Of course Black’s own knight is in the
way at d4, and would need to be vacated with
a threat that forces White’s response; and the
other White bishop—the one at f3—is not yet
loose. But both problems can be addressed
with an exchange. Black plays NxB; White
replies KxN. In addition to bringing the king
onto the same rank as the loose bishop, the
exchange opened the d-file for Black’s rook.
Now Rd3+ wins the piece.
A general point: When you have a chance to
exchange minor pieces, as Black did here, as
a matter of course you should play through
the exchange in your mind’s eye to see how it
leaves the board—what lines it opens, what
becomes loose, etc.
Dg266: White to move
Dg267: White to move
Dg266: What Black pieces are loose? The
knight and rook. Focus on the knight, since it
makes a good target for an attack by your own
rook. White’s rook can attack the knight in
one move (either Rc3 or Rd6). If only the
Black king could be pushed onto the same
rank or file as the knight; but how? White’s
bishop is no help because the king is on the
wrong color square. But White has pawns
near Black’s king, and pawns are perfect for
pushing pieces around by threatening them.
Put more simply, what checks does White
have? Answer: push a pawn to f4 or h4. Either way the only legal move for Black’s king
is onto the sixth rank. When the enemy king
is forced to move, you reevaluate what would
be possible—what new checks. Answer:
Rd6+, winning the knight.
Here White has Rxg6+, which goes nowhere;
but then he also has Qd2+ (don’t overlook
backward moves!). Black is forced to move
his king onto the same rank as his queen.
Rd7+ forks them, and a move later Black
wins a queen for a rook. Notice that attacks
by the rook against a queen, like similar attacks by a bishop, only work if the attacking
piece has protection; here White’s queen still
guards the eventual forking square (d7) when
it delivers check from d2.
So that’s the forking idea. But actually White
has something even stronger. 1. Rd6 threatens
to mate next move with h3-h4. Blocking the
idea with h5-h4 doesn’t work for Black, because then White has f3-f4+ (forcing the king
to h5) and then Bd1#. Instead Black has to
reply to 1. Rd6 with Rxa4, using his rook to
defend the fourth rank. But then White has
BxR and the threat of f3-f4#. Black can fend
off the immediate mate threat with f5-f4, but
promptly loses his knight to RxN—and now
he is out of pieces. The sequence is worth
playing through in your mind's eye a few
times.
Dg267: Avoid doing anything without first
examining any checks you can give and their
consequences.
Dg268: White to move
Dg268: Near the beginning of the James Bond
movie From Russia with Love, a chess match
is depicted between the villainous Kronsteen,
playing the White pieces, and one McAdams.
The position is pictured here. Kronsteen plays
1. NxB, discovering check. McAdams replies
Kh7. Meanwhile Kronsteen has been summoned away by a secret message from his
bosses at SPECTRE; so now he plays 2.
Qe4+—and McAdams resigns. Black’s best
reply move would have been 2. …g7-g6,
blocking the check, but this creates a fork for
White with Rf7, winning Black’s queen for a
rook. The position was based on one that
arose between Boris Spassky and David
Bronstein in Leningrad in 1960, though in the
real game there were White pawns on c5 and
d4. Bronstein resigned after Spassky played 2.
Qe4+.
As a study in the rook fork the lesson of the
position lies in three events that make Rf7+
possible: (a) Black’s king stepped forward
from the eighth rank to the seventh, a classic
site for rook forks because the rank can't be
guarded by pawns and tends not to be patrolled (for defensive purposes) by rooks. (b)
One of Black's pawns stepped forward from
the seventh rank to the sixth, opening a line
between the king and queen. And (c) White’s
Qe4 cleared a path up the f-file for his rook.
Each of these events is a type that can cause
new tactics to become available: pins and
skewers, as we shall see later, and forks, as
we see here.
That’s all you need to see about the position
for present purposes, but for the sake of completeness we can consider a couple of other
variations. What, for example, is Black’s best
reply to White’s initial 1. NxB? It’s 1. …Ne6,
which blocks the check and pretty well puts
out the tactical fire. Suppose, however, that in
reply to 1. NxB Black plays 1. …Kh8. Now
White can’t play Qe4 with check to clear the
way for the rook fork. But White still has a
wonderful move: Qc4, aligning the queen
with the bishop on b3 and threatening to mate
next move on g8. Black has no good reply.
Kh7 doesn’t help at all. Qe6 blocks White’s
queen but now allows White to play RxN+
instead. If Black recaptures RxR, his queen is
left loose and White takes it. If Black doesn’t
take the rook he soon will be mated. So
Black’s best move after 1. NxB+, Kh8; 2. Qc4
is Nd7, clearing a path for the e8 rook to use
to protect the mating square g8. But the
knight’s move leaves g6 loose, and White
uses it to play Ng6+, a fork that takes Black’s
queen next turn.
Finally, suppose that after 1. NxB, Kh7; 2.
Qe4+, Black declines to step his g-pawn forward and instead plays 2. …Ng6. This blocks
the check without opening up the seventh
rank for the rook fork White would like to
play. But now Black is in bigger trouble, as
White has 3. QxNg6, Kh8 (forced); 4. Nf7+
(always look for the next check in these situations). Now if 4. …Kg8, then 5. Ng5+ (discovering check by the bishop), and White is
about to mate. Or if 4. …QxN, then 5. RxQ
and White again will mate soon; Black can
use his rook to throw some checks at White’s
king, but this is just desperation. Other replies
to White's 2. Qe4+ likewise end with Black
getting mated. E.g., 2. …Kh8; 3. Rxf8+, RxR;
4. Ng6+, Kh7; 5. NxR++, Kh8; Qh7#.
Some of the ideas in these variations—as well
as the idea of the discovered check that starts
the sequence when White's knight steps away
from f7—will be easier to understand after
you have worked through the later parts of
these lessons.
2.4.5. Clearing Paths.
In the following positions there is a rook fork
waiting to happen: two enemy pieces on the
same rank or file, one of them loose, or one of
them the king, or both. But there are pieces
between them, or between the rook and the
forking square, that have to be gotten out of
the way for the double attack to work. Again
it is important to recognize the basic visual
patterns involved—enemy pieces on the same
rank or file, suggestive of a fork—without
being thrown off by obstructing pieces that
you might be able to remove.
Look for visual patterns on the diagram.
Dg269: We see a familiar layout of Black pieces, with the king and a loose knight — prime
targets for a fork—on the seventh rank.
Dg269: White to move
If White could get a rook between them, the
knight would be his. The Black pawn at e6 is
the only thing in the way. The natural method
for getting a pawn out of the way is to take
something it protects. Here it protects the
pawn on d5, so White takes it with Bxd5. If
Black replies e6xB, now Re7+ forks king and
knight. The net gain is a pawn.
attack with White’s rook: a king and loose
bishop on the same rank with nothing between them. Can the Black rook be attacked?
Dg271: White to move
Dg270: White to move
Dg270: White has no checks that are immediately productive (though Ne7+ is not bad), so
he looks for any Black pieces that might be
loose. There is one: the bishop on h6. He has
no direct way to attack it, but since a loose
enemy piece is a big opportunity White considers whether he might build a double attack
against it. Look for a visual pattern: the
bishop is on the same rank as the Black
queen. If the pieces between them could be
cleared out of the way, White would have a
fork with Rc6; the rook would be protected
from QxR by the pawn on d5. Of the two men
in the way, White can control its own—the
knight at c6. Where can it move, and with
what results? The only capture it can make is
NxN. Black would reply d6xN; the pawn gets
pulled off the sixth rank. Now the way is clear
for Rc6, forking bishop and queen and thus
winning a piece. The initial capturing sequence here illustrates a pattern of general
interest: when two pieces need to be cleared
off of a path, sometimes moving one of them
also can force away the other.
Dg271: Look for a pattern; look for enemy
pieces arranged on the same line. Black’s
king, rook, and bishop are spread along the
back rank. If the rook were out of the way
there would be a classic setup for a double
No. Can White attack something the rook
protects? What does it protect? The knight on
e4. So White takes the knight with NxN,
Black responds with RxN, and now with the
Black rook out of the way White plays Rd8+
and wins the bishop. That would be one way
to see the position; another would be to begin
by experimenting with captures. White sees
that he can play NxN. Automatically he imagines it and considers what it would do to the
board. It would cause Black to play RxN.
Then what would be possible—especially
what checks? Answer: the fork Rd8+.
When the queens are faced off against each
other like this, exchanging them is an option
both sides have to consider at every turn. A
capture by either player will require an immediate recapture, which may open lines, leave
loose pieces elsewhere, etc.
Dg272: White to move
Dg272: Here White imagines QxQ and
Black’s compulsory recapture NxQ. This
simple sequence leaves behind loose Black
pieces on c5 and f5 (whereas there were no
loose Black pieces before), and a clear path
for White’s rook from e1 to e5 (whereas there
were two pieces in its way at the outset). Now
the rook fork Re5 wins a piece.
This position is a good illustration of how a
single exchange can radically alter the tactical
opportunities on the board. The solution is
easy enough to spot if you understand the
significance of loose pieces—and probably
impossible if you don't.
the b2 bishop, which would have been left
loose by the exchanges that started the sequence. The rook fork Rd2+ then wins the
bishop next move.
The prospect of a rook fork is nowhere in
sight at the outset of this position. You would
see it only by patiently imagining the exhaustion of exchanges on c4, then your next
check, then the resulting pattern with the king
and loose bishop on the same line. If the latter
position were set in front of you its solution
would be clear. It is worth studying this position until its solution is equally clear because
you are able to visualize the consequences of
those initial moves. Notice that it involves
several of our major themes in constructing
forks: creating a loose target, loosening the
forking square, and moving the enemy king
onto a square where it can be forked.
Dg273: Black to move
Dg273: Start by seeing that the tension in the
position is focused on c4: Black has two
pieces attacking the bishop there; White has
two pieces defending it. This means Black
can’t win anything immediately with captures
on that square, but if you stop there you're
thinking about the position the wrong way.
The important question when you have a
chance to force a series of exchanges is how
the board would look afterwards — what
checks you then would have, and whether any
of them would be (or could be made into)
forks or other tactical devices.
Okay, so imagine liquidating the pieces
trained on c4. Black plays BxB, and White
replies RxB; Black plays RxR, and White
replies RxR. The two sides have traded bishops and rooks. More importantly, one of the
rooks in White’s battery is off the board and
the other ends up on c4, leaving White’s back
rank weak (bereft of defenders). The natural
thought for Black, then, is to drop one of his
own rooks there with check: Rd1+. This
forces White’s king to f2—on the same file as
Dg274: Black to move
Dg274: You might start here by looking for
visual patterns for Black to pursue. The key
thing to notice is the spread of pieces on the
second rank and especially the White bishops
there. Of course there are pieces between
them, but if the queens were removed a double attack would be possible; as usual the second rank is a great place for a fork because it
can’t be defended by pawns. The bishops
there are especially nice targets because
unlike the White queen that also is there, they
wouldn’t be able to strike back at a rook that
jumped between them.
So Black goes to work to get rid of the obstructions, starting with the obstructing piece
that he can control: his own queen. Experiment with exchanges. If Black plays QxQ,
White plays RxQ. Now only the White rook
would prevent a fork of the two bishops. Can
it be taken? No. Can something it protects be
taken? No. But can the rook be threatened
and perhaps driven away? Yes, with Bb4.
White moves the rook so as to avoid BxR;
and now Black plays Rc2, attacking both of
the now-loose bishops and winning one of
them.
ten with the rook than with the other pieces
we have considered because the rook less
often is in position to do both of those things.
We consider it here only briefly.
2.4.6. Working with Mate Threats.
Dg276: Black to move
Dg275: Black to move
Dg275: What White pieces are loose? The
bishop at c3. Black needs a way to attack it
and attack something else at the same time—
preferably the White king. His queen is off
the board, so what might he do with his rook?
He can attack the loose bishop with Rd3. That
move doesn’t attack the king directly, but the
opportunity presented by the loose piece is
important, so think harder; examine the White
king’s position carefully. The bishop at b6
cuts off the g1 square. The bishop on e4 pins
the pawn on g2. So if Black could get a rook
onto the h-file, it would be mate. This idea
can be put together with the previous one:
Rd3 both attacks the bishop and threatens to
end the game with Rh3#; after White fends
off the mate threat, Black plays RxB. The
lesson is to always be aware of the enemy
king (not to mention your own) and any of
your pieces that constrain it.
Dg276: This time you might begin by inspecting the enemy king (White's) and the constraints on its movement. Black’s bishop attacks h2, and g1 is off limits because White’s
own knight is there. So the White king has
very limited mobility, and this vulnerability is
a tactical opening. If Black could just aim
another piece at the king, he might have a
mating threat; even if it were easily thwarted,
it might enable him to win material by serving
as the anchor for a double attack. Best of all
would be to land an attacker on h2, since
Black already covers that square with his
bishop. His rook can prepare to do this with 1.
…Rf2. This creates multiple threats at once,
which is your general goal as a tactician. The
first threat is that White’s queen is now attacked twice and guarded just once (by the
knight on g1). If White’s queen moves, either
to play QxQ or just to get someplace safer,
Black also threatens to mate with Rh2. If
White replies to Rf2 with QxR, then of course
Black plays QxQ. White’s best reply probably
is to play his own rook from d7 to d2, thus
preparing to recapture, with a loss, after Black
plays RxQ.
2.4.7 Strategic Implications.
The motif illustrated by this position—the
fork that targets an enemy piece at one end
and threatens mate at the other—is familiar
from the previous chapters. It occurs less of-
Rooks do not need to be in the center of the
board to be effective. In principle, at least,
they have the potential to attack the same
number of squares—a full rank, and a full
file—no matter where they sit on the board.
They generally do need to be moved out of
the corners to gain power, however, and moving a rook toward the middle of the board has
the particular advantage of making it easier to
launch double attacks with the rook against
pieces on the same file (i.e., pieces aligned
vertically). It stands to reason: double attacks
require rooks to get between two enemy
pieces; the farther the rook is advanced into
the center, the greater the opportunities for
enemy pieces to end up on both sides of it.
Likewise, rooks on the four middle files are
more likely to be able to get between enemy
pieces lying on the same rank (i.e., aligned
horizontally). Glance at where the rooks that
inflicted the double attacks in this chapter
generally were positioned at the start of the
sequence; ideally, that is where you want your
rooks to be: centralized.
Whether they do their work out on the board
or from posts on the back rank, what rooks
most generally require are open files ahead of
them. They don’t do much good sitting behind their own pawns unless the pawn is on
its way to promotion on the opponent’s back
rank. Make it a priority to get your rooks onto
open files (or half-open files—files where
none of your own pawns sit, even if your opponent still has a pawn in place.) Move your
rooks there or move pawns out of their way
by making captures with them.
Dg277: Black to move
Dg277: Indeed, there is a whole opening—the
King's Gambit—premised partly on this idea.
White offers to sacrifice his f-pawn on the
second move, as shown to the left. What does
this pawn push on the second move have to
do with rooks?
Everything: once his f-pawn is gone, White
will have a half-open file onto which he can
bring his rook just by castling on the kingside
a few moves later. That rook suddenly can
easily become a terror, bearing down on f7—
typically a weak point in Black's position. Of
course there are many other consequences of
the King's Gambit; it's a complicated opening.
The point for now is just to see how gaining
an open avenue for a rook can be a part of the
planning from the first steps of the game.
In a sense all this is just another application of
some principles given at the end of the chapter on the bishop fork. Here, as there, pawn
moves are significant in part because of the
lines they open and close. From an offensive
standpoint, a pawn capture that creates an
open line for a rook may be very valuable for
just that reason; from a defensive standpoint,
think carefully about any capturing sequences
that will have the effect of opening files for
your opponent’s rooks. And once a file does
open, try to claim it by planting a rook at its
base.
The positions in this chapter also underscore
another point we have seen elsewhere: the
importance of creating open lines to the enemy king and of avoiding open lines to your
own king. In the rook’s case an “open line”
includes the back rank if it can get that far and
no defenders are there. Anytime an enemy
rook has an open path to your back rank, or a
path obstructed only by its own pieces, start
worrying. Anytime your own rook is in that
position, start experimenting.
2.5. The Pawn Fork.
2.5.2. Exchanges to Create Working Pawn
Forks.
2.5.1. Introduction.
We now consider double attacks by the pawn.
This chapter, too, is shorter than the earlier
ones on forks because attacking patterns involving the pawn tend to be simple. A pawn
can fork two enemy pieces that are on the
same rank and separated by one square.
(E.g., the Black rook and knight in the diagram, which can be forked with f2-f4.) Any
two enemy pieces are fine, at least if the pawn
has protection; the joy of attacking with
pawns is that they are worth so little. A pawn
for a piece—any piece—almost always is a
good deal, so every piece must fear them.
And of course you start with eight pawns, and
they often are near the combat zones of the
board. They can jump from their starting position into the center in one move, and can
move diagonally when they capture. We will
see pawns taking advantage of all these capabilities in the examples that follow.
Dg279: White to move
White looks for a promising geometric pattern
and sees that Black has two pieces—the
bishop and knight—on the same rank and
separated by one square: the classic setup for
a pawn fork. The only hitch is that the bishop
is an unsuitable target because it can capture
the pawn. White asks whether he can take the
bishop with another piece, causing it to be
replaced by a better target; he can, with NxB.
Black recaptures with RxN, and now White
plays the fork f2-f4, winning the knight after
the rook moves.
Dg278: White to move
Dg278: By the way, what will happen in the
diagram after White starts with f2-f4? Black
might try a classic line of reply to a fork: he
can move one of his pieces out of it with
check by playing Re1. Now White can't play
f4xN; he has to move his king to f2. But
White still will make his gains, because now
he threatens KxR and (still) f4xN. Black can't
escape both threats.
Dg280: White to move
Dg280: Here the concept is similar but harder
to see. White almost has a pawn fork with d5d6, but the move attacks a queen and a pawn,
an unsuitable target. If only the Black king
were on e7 rather than d7; and in that fantasy
lies the solution: draw the king onto e7 by
attacking the pawn there that only the king
protects. White plays Rxe7, Black replies
KxR (if Black moves the king, White skewers
the queen with RxQ), and now the pawn push
d5-d6 wins the queen (the knight on c4 provides the protection the pawn needs to attack
it).
Notice, by the way, that White does all this
while threatened with b5xN. The usual lesson
repeats: when under even an obvious threat,
consider whether you can effectively go on
the offensive with a check of your own.
Dg282: Black to move
Dg281: White to move
Dg281: The same idea in different form.
White sees that his pawn on g3 is one move
from attacking the enemy queen on h5. The
move would be a lot more interesting if it also
attacked something else. There is not yet a
working fork because on f5 Black has a
pawn—an unsuitable target. So again White
asks whether he has anything he can use to
capture the pawn and cause it to be upgraded
to a target that will work. He finds one option
for the purpose: Bxf5+. Black’s only legal
reply is KxB, leaving his king and queen in
position to be forked with g3-g4. Of course a
pawn fork of the queen only works if the
pawn has protection, and it does—from the
pawn on h3.
Again, another way to have seen this would
have been to examine every check. White has
two: Rb6, which Black escapes easily, and
Bxf5, which looks improbable but requires
Black to move his king to recapture. You
imagine this response, see the telltale resulting position of Black’s king and queen, and
take it from there.
Dg282: Where does White have pieces vulnerable to a pawn fork?
The knights on e4 and g4 are perfectly positioned. The only obstacle is Black’s own
queen at f5. When our own pieces obstruct
our plans, our first recourse is clear: try to
move them out of the way in a violent fashion
that requires a time - consuming response
from the enemy. What can Black attack with
his queen? White’s queen: 1. …QxQ, 2.
e2xQ, and now f7-f5 wins a knight.
Dg283: Black to move
Dg283: Where does White have pieces vulnerable to a pawn fork? He has pieces on c3
and e3, and Black has a pawn at d5, so the
makings of a fork are in view. There are two
obstacles to its success: the White knight on
d4 is in the pawn’s way and will need to be
cleared somehow; and if a bishop is going to
be one of the targets of the fork, the pawn will
need protection so it doesn’t get captured.
Once you understand that those are the problems you need to worry about, the solution is
clear enough: play c7-c5. The threat drives
the knight away (every piece flees a pawn),
and also creates protection for the d5 pawn
when it then moves to d4, forking knight and
bishop.
It's worth having a good look at the starting
position here. It's important to see the potential for a pawn fork in a situation like this
despite all the other distracting pieces in the
vicinity—particularly the knight on d4.
pawn on d5 is a square away from being able
to fork them. The problem is that d6 is occupied by an enemy pawn. How do we get rid of
it? In familiar fashion: take something it protects, forcing it to move to recapture. So
White plays NxN; Black recaptures d6xN;
and now the fork d5-d6 wins Black’s other
knight.
Dg284: White to move
Dg284: What Black pieces are vulnerable to a
pawn fork? His knight and bishop, of course.
What are the obstacles? The Black queen,
which blocks the pawn’s path; and again the
pawn will need protection if it is going to attack a bishop. The problems here are the same
as in the previous problem, and so is the solution: f2-f3 drives away the queen and also
provides protection to support the fork e3-e4
that follows. (Note that after 1. f2-f3, Black
has to move his queen somewhere; pay attention to where it will go, as its options are very
limited. Black likely will play it to h4. Now
White pauses to play the exchange 2. QxQ,
g5xQ; he plays this first because his own
queen is unprotected. Then he plays the fork
in the middle of the board.)
Dg286: White to move
Dg286: It is White’s turn four moves into the
Four Knights opening. He is considering Bc4
to develop his pieces further. What happens if
he plays that move? Picture it: his bishop and
e4 pawn will be in the classic position to be
forked by Black’s d-pawn, and Black would
be able to replace the pawn on e4 with a suitable target by playing Nxe4, inviting the reply
NxN. Now White’s knight and bishop would
be forkable with d7-d5. True, White could
then take Black’s pawn with his bishop
(Bxd5), but then Black plays QxB. When the
smoke clears, Black will have won no material but will have a better position: a pawn in
the center and both bishops ready to move.
The point of the position is not the precise
outcome, though; it is the importance of hesitating before leaving one of your pieces one
square away from any of your own pieces or
pawns on the same rank. Consider whether
your opponent could start an exchange that
would create a working pawn fork at the end.
2.5.3. Forcing Pieces into Place with
Threats and Checks.
Dg285: White to move
Dg285: By now the idea here should be easy
to spot: Black’s rook and c7 knight are a
square apart on the same rank, and White’s
So far we've dealt with cases where your opponent began with two men ready to be forked by a pawn. One of them may have been
an unsuitable target—e.g.,an enemy pawn that
needed to be upgraded with an exchange —
but the basic geometric motif already was
present. These next positions differ because
the geometry for a pawn fork needs to be created; enemy pieces have to be forced onto
squares where they can then be forked. How
do you force a piece onto the empty square
where you want it to go? Sometimes a threat
will do the trick. Normally your opponent will
move a threatened piece someplace safe, but
if it has a limited range of motion because
some of its escape squares are blocked or attacked, a threat may force it where you want
it to go. Consider this section a general set of
lessons in paying careful attention to where
threatened pieces will move.
Dg287: White to move
Dg287: In this first example White has a
pawn that can jump into position to attack the
Black queen with g2-g4. The threat is of limited interest by itself, but it would make a
terrific first half of a double attack: if Black’s
king could be goaded onto f5, White would
have a pawn fork. Of course White's knight is
there now, and Black's king will want to avoid
capturing it precisely because of the fork that
then results. But whether these thoughts occur
to you or not, on principle you would want to
examine every check White can give and its
consequences. White has a check at d4 with
his knight that achieves nothing. He has
checks with the queen at d7 and f7 that lose
the queen right away, but another check at e7
where the queen enjoys protection from the
knight. How would Black respond? He would
have to move the king with KxN. White
imagines the board as it would then look and
realizes that Black's king and queen would
then be forkable with g2-g4.
A loose end remains. When we went over
White's checks, we left one out: Re1. It looks
good; indeed, it forces the same initial result
as Qe7: Black has to play KxN, and now
White has that same pawn fork. But there is a
grave difference in what follows from there.
After White plays g2-g4, Black naturally
moves his king away with Kxf4, and then
White has g4xQ (the execution of the fork)—
but now notice the state of the g-file. White's
pawn no longer is there; the only things left
behind are White's king and queen: a perfect
chance for a pin by Black, which he exploits
with Rg8. White can't move his queen, and
will lose it next move. White's better starting
move, Qe7, avoids this calamity by getting
the queen off the g-file right away.
The general lesson of this last variation is to
be careful to study all of your checks. Sometimes one looks as good as the next for a purpose on first inspection, but turns out to have
quite different side effects. The more specific
lesson is to be alert to one particular type of
side effect: lines that get opened by a tactical
sequence, such as the g-file in this case. This
last possibility may seem startling and worrisome if you haven't studied pins; but once you
get through that part of this project, you will
know that the sight of White's queen and king
on the same line is something to notice from
the beginning here.
Dg288: Black to move
Dg288: Look for patterns in the layout of
White’s pieces or for threats you can make;
the result either way should be to see Black's
potential pawn fork d4-d3. The problem is
that once the pawn arrives on the forking
square it would be attacked twice — by
White’s queen and rook—and protected only
once, by Black’s rook at d8. So the pawn gets
taken if it steps forward. Yes, but let that sequence play out in your mind’s eye: 1. …d3;
2. Rxd3, RxR; 3. QxR, and now what would
be possible on the resulting board? White’s
queen and knight would be arranged for the
fork e5-e4, winning the knight at f3. In effect
the initial fork was just another threat that
drew the White rook, then (after an exchange)
the White queen, into position for a different
fork.
Incidentally, note the importance of Black
playing the exchange RxR, QxR before executing the fork at the end. If Black plays the
pawn fork against White’s rook and knight
after the rook has moved to d3, White breaks
out of it with RxR+. Once the rook has been
replaced with White’s queen, however, White
has no good way to break out of the fork. The
general points are (a) to always ask whether
you can improve the target of a double attack
with another exchange, and (b) to always consider what your opponent’s best reply to the
fork would be; he may have a check or threat
that would enable him to break it—especially
if his king is not one of the parties to the fork.
White gets interested in threats he can make
against the bishop and their consequences,
and looks at a2-a3. Study the bishop’s flight
squares and you see that if it moves any
deeper into White’s territory it gets taken, so
it has to move instead to a5. Now Black’s
bishop and knight would be a square apart on
the same rank, so b2-b4 would fork them; the
pawn on a3 gives the b4 pawn the protection
it needs to be able to attack the bishop.
The general lesson: keep an eye out for enemy pieces that are hemmed in by their own
pieces or by the edge of the board; often they
have few options if they are attacked, making
the consequences of the resulting sequence
easy to predict and sometimes making a tactic
easy to execute.
Dg290: White to move
Dg289: White to move
Dg289: Sometimes a threat by one pawn will
force an enemy piece into position to be
forked by another. The previous position was
one example; here is another that works a bit
differently. White sees that Black’s bishop
has limited opportunities for escape, as the
knight on c5 cuts off its main line to the rear.
(A bishop with so little room to retreat is a
vulnerability you want to spot in your opponent's position and avoid in your own.) So
Dg290: The same idea. Again observe that
that Black’s bishop has limited motion (look
behind it; it can’t retreat toward a7). So White
considers threatening it with b2-b4. Here as
before, Black’s bishop gets taken if it tries to
escape by moving farther into White’s territory. Instead Black might play Bd6—putting
the bishop one square away from the knight
on the same rank. Now White forks the two
pieces with e4-e5, with cover for the pawn
supplied by the bishop at f4. (Or Black replies
to b2-b4 with the suicide run Bxf2; after
White replies KxB, Black has Nxe4+, and
White ends up winning a piece for two
pawns.)
Dg291: This time White's bishop on b5 is the
piece with a limited ability to retreat. When
you see a piece trapped in this way, think
about threats against it. For Black that means
considering Rd5 here. The bishop then gets
taken if it moves to e2, d3, c6, d7, e8, or a6.
Its only safe move—and it's only temporarily
safe—is Bc4. (If White tries Be8, Black plays
Kf8 and now the White bishop is attacked
twice and defended once with nowhere good
to go. Remember that Black's rook would be
on d5....) What then would be possible?
Dg291: Black to move
simply pushed it again.) So d5-d6 then wins a
knight, with the bishop on g3 providing necessary protection against Qxd6.
That is the idea, anyway. Against an alert
player the outcome would be favorable but
not quite so simple. As usual you need to consider whether he might seize the offensive.
Here Black’s best reply to d4-d5 is not to
move his knight to c7; it is to play Ne7xd5.
Then when White plays e4xN, Black has the
recapture Qxd5. White still gains a piece for
two pawns, but Black has reduced his losses
nicely. There is a valuable defensive lesson in
this for occasions when you find yourself the
target of an unavoidable fork. If you are destined to lose a piece, you might as well do
whatever damage you can with it (or with
another piece you can sacrifice in its place). A
doomed piece that has this odd sudden liberty
to go on a suicide mission is known not as a
kamikaze but as a desperado.
White’s queen and bishop would be set up for
the pawn fork b7-b5, with Black’s rook at b2
furnishing the cover.
Dg293: Black to move
Dg292: White to move
Dg292: No Black pieces are poised to be
forked. But again it is good practice to examine the consequences of threats you can make
by advancing your pawns. White has just one
such threat to consider: d4-d5. The Black
knight would flee, but don’t stop with that
observation; ask where it would go. It has
only one safe square: c7. Re-evaluate the
board as it then would look and notice that
Black’s knights now would be a square apart
on the same rank. (Alternatively, after pushing forward a pawn to threaten something,
you can always ask what would happen if you
Dg293: The drill: look at any threats you can
make with your pawns and ask what consequences would follow. It is especially important to consider this when the threatened piece
has little room for escape. Here Black has the
simple g7-g6, putting pressure on the queen.
The queen’s freedom of movement is limited;
it has to move to h4. Now what? Well, Black
can attack it again: g6-g5, and now White is
in a jam. To see why, consider his king; for it
is affected by these movements of your gpawn, which now seals off f4 and h4, and also
protects those squares if you want to occupy
them yourself. So look for your next check
find Bxf4—mate.
This means that after Black's second push of
the g-pawn, White wouldn't want to play Qh5.
He would need to try f4xg5. Too bad about
that f4 pawn of White's. But put this together
with the earlier point about f4—its vulnerability to Black's bishop—and a new idea comes
to mind: if the pawn at f4 first could be replaced with the White king, Black could fork
White's king and queen by putting his pawn
on g5. So Black reconsiders that check we
mentioned: Bxf4, which he plays early: before
or after White’s queen has retreated (naturally
you could have found the whole idea here by
starting with the check Bxf4). Whether White
plays KxB or moves his king to h4, Black’s
marching g-pawn then wins the queen.
In the game this position came from, between
Tal and Botvinnik, it was White’s turn to
move. Tal played Nc3-d5. Now if Black plays
g6-g5, White plays NxNf6+. Since this
checks the king, Black can’t play g5xQ; he
has to capture White’s knight. After that exchange gets rid of the knight on f6, White’s
queen has plenty of flight squares and the fire
is out. But of course the first important point
in all this is for White to recognize that he is
in danger. The tipoff is the immobility of his
queen.
2.5.4. Forks By Marching Pawns.
A similar result can be reached by skipping
Bxf4+ at the beginning and just playing 1.
…g7-g6; 2. Qh4, g6-g5; 3. f4xg5—and now
3. … Bxg5 attacks and wins the queen. The
bishop has protection against capture, and if
White tries to move the queen to safety on h5,
Black has f5-f4. This forces Kh2, which in
turn allows Black to play Rh1#.
Dg295: White to move
Dg294: Black to move
Dg294: This time White’s queen is the piece
that is cramped: it’s up against the side of the
board with little room to retreat. Black considers a threat against it with g6-g5. Where
will the queen go? It gets captured if it moves
to h5 or to anywhere on the fourth rank (look
and see). So it has to move to h3. Yet now its
relationship with the knight on f3 calls for a
pawn fork: g5-g4 wins the knight, with
Black’s own knight at f6 supplying the
needed protection for the pawn.
Dg295: White looks for promising patterns
and sees Black’s queen and knight in a vulnerable position: a square apart on the same
rank. White has no way to get a pawn onto c5
in one move, but perhaps he could march it to
c5 by threatening something with it along the
way. The small push c3-c4 threatens Black’s
knight; after it flees, c4-c5 then forks queen
and knight—with the necessary cover supplied by White’s own knight on b3.
When you find a sequence like this, of course,
you understand that it is the ideal sequence.
Your opponent may make sacrifices to prevent it from playing out quite as you imagined. Thus after White plays 1. c3-c4, Black’s
best option is not to move his knight and allow the coming knight fork. It is to launch a
counterattack with 1. …Bf5, attacking
White’s rook. It's a nice attack; for if White
moves his rook to a1 or c1, Black then plays
Bxb2 with his dark-squared bishop and now
the rook has no escape. So White's best reply
to Black's Bf5 is to forget the rook and play 2.
c4xN, BxR; 3. QxB, Nxd5. White has won a
knight and a bishop for a rook and a pawn.
no checks in the picture), because he may
then be able to buy time by making similar or
worse threats of his own elsewhere. In this
case it's not an issue, however, White has no
effective way to derail the fork.
Notice that in this sequence the pawn fork
never actually gets played. It has to be seen,
though, because the threat of it causes everything else that happens instead. In good play,
forks and similar tactical devices frequently
do their most important work in this indirect
way: they are seen and avoided, but the effort
to avoid them forces material or positional
sacrifices that end up being decisive.
Dg297: White to move
Dg296: Black to move
Dg296: Here is a similar position. What
White pieces are poised to be forked by a
pawn? The bishop and knight on f3 and h3 are
in the classic position. Black can’t get a pawn
onto g4 in one move, but he can march it
there, and leave White no time to defend itself, by playing g6-g5, threatening White’s f4
bishop. The bishop runs away, and now g5-g4
wins a piece. (The Black pawn on f5 provides
the necessary cover, of course.)
Here as in the previous position your opponent can thrash around a bit; after the initial
pawn push, White can throw in a capture
elsewhere like c4xd5. In this case Black just
recaptures with his e-pawn and the forking
threat is both renewed and unavoidable for
White, but the point is that you always want
to make sure you have considered what counterplay your opponent might be able to offer
elsewhere on the board. This is especially
important when the sequence you contemplate
doesn’t threaten the enemy with anything
more than the loss of a piece (i.e., you have
Dg297: The same idea once more. The first
thing is to train your eye to see two pieces
lined up with a single square between them,
as Black's queen and knight are arranged in
this case. White can’t get a pawn to e5 in one
move, but he can do it with a two-step push:
e3-e4 forces the bishop to move because the
pawn is protected three times (count 'em).
Now e4-e5 wins the knight after the queen
moves; this time the rook on e1 provides the
needed cover.
Black has no effective counterplay here, but
as an exercise imagine the position with
White’s pawn on h3 moved back to h2. Can
something so subtle make a difference? It
does: for then after 1. e3-e4, Black has 1.
…Ng4—threatening mate with Qxh2. The
mate threat can be evaded in various ways
(e.g., with 2. BxN, BxB; or with the simple 2.
e4-e5, forcing Black’s queen to retreat), but
now the forking threat is over because Black's
knight has left f6.
There are a few lessons to take away from the
variation just discussed. Again, especially
when you are not operating with checks you
have to ask what threats (particularly what
checks and mate threats) your opponent might
be able to make as an alternative to playing
into your hands. In this case you would want
to be especially wary of moves he can make
by either of the pieces being threatened, and
wary as well of threats against your king's
position. If an enemy queen already is aimed
at a square next to your king, as Black's is
here, remember that your opponent may be
able to create a mate threat by simply adding
another attack against that square. Maybe the
mate threat can be defused easily, but it will
cost you time. Finally, you can treat this as a
little study in the value of a well-placed pawn.
In the position as actually diagrammed, the
pawn on h3 is doing quite helpful work by
keeping Black's f6 knight from jumping to g4.
This is an important office of pawns: guarding
squares where you don't want enemy knights
planted.
moving is what it used to protect that may
now be loose.)
Now let’s think about counterplay for a moment. After c2-c4, is it clear that Black has
nothing better to do than move his knight out
of the way and allow the fork on c5? What
attacks of his own does Black have as options? He can play BxB, freeing one of the
pieces to the potential fork with a capture; the
question is whether, after White recaptures
h2xB, Black has bought time to rush his
knights to safety. Almost, but not quite. For
when Black played BxB, the knight on d5
became pinned to its king and thus cannot
now be moved. So after White recaptures on
g3, the best Black can do is take the c4 pawn
with his other knight (Nb6xc4), thus allowing
White to play RxNd5 next move. White wins
a piece for a pawn, but again the sequence is
not quite as simple as it might look at first.
Dg298: White to move
Dg298: White sees that Black has left two
pieces—his bishop and his b6 knight — a
square apart on the same rank, inviting a
pawn fork. White’s c-pawn needs two moves
to get there, which is fine so long as the first
move is a threat that requires a timeconsuming reply: after c2-c4, the knight
moves, and then c4-c5 wins a piece by forking the knight and bishop. But wait; where is
the cover the pawn needs before it can attack
a bishop that has the power to capture it back?
There is none, but none is needed because
after the knight on d5 moves the bishop is
pinned to its king by White’s rook on d1. Recall that even if a target looks unsuitable because it can defend itself, it is powerless to do
so if it is pinned; thus whenever a piece
moves, as the d5 knight does here, consider
whether the move creates any open lines, any
pins, etc. (If Black were to reply to the initial
pawn push with Nb6xc4, he would be leaving
his other knight exposed to RxN; another
question to ask when you imagine a piece
Dg299: Black to move
Dg299: Black experiments with the effects of
advancing a pawn and finds that e4-e3 moves
near to forking White’s queen and rook. Of
course White wouldn't allow that; but go farther and ask precisely what he could do to
prevent it.
(a) White won't be playing d2xe3 because the
d2 pawn is pinned to his queen. (In other
words, Black would have QxQ; if White then
replies RxQ, Black plays RxR#.)
(b) If White responds to e4-e3 by moving his
queen out of the way (say, to c2), Black plays
QxR#.
(c) If White moves his rook to g1, Black can't
quite play BxR, because his own pawn would
be blocking the way on e3. But he can use
that pawn to take White's pawn on d2, and
thus threaten to take the c1 bishop next move;
once White avoids that threat (with Bb2), then
Black has BxR after all, winning the exchange and a pawn after White recaptures.
(d) So suppose White instead plays Re1. This,
too, fails—to e3xd2, forking rook and bishop.
White plays Bxd2, and then Black has QxB,
winning a piece.
The important thing to notice is how a pawn
can march not only forward but also diagonally by making a capture, expanding its potential to inflict forks. And then there is a larger point to observe: the pressure on White’s
king that indirectly drives the tactical sequence here. The king is stuck in the corner;
the Black queen’s threat to mate on White’s
back rank (QxR) effectively freezes White’s
queen in place, as it must defend against this
possibility. These pressures on White’s king
do not enable Black to mate, but they do constrain his other pieces severely enough to
make a capture of material possible. It is important to appreciate how such accumulations
of pressure against one point—especially
though not only against the king—can end up
paying off with gains elsewhere as your opponent has to make sacrifices for safety’s
sake.
compensation. But Qd3+ forces White to play
QxQ, to which Black replies e4xQ. Now reexamine how the board would look: the pawn
on d3 would be attacking the White knight on
c2; and if the knight moves, the pawn advances to d2, forking both rooks. Could it
then be taken by the king? No, because the
knight formerly on c2 will have moved, creating an open line for the Black rook on b2 to
provide cover for the pawn. So White is better
off letting his knight on c2 get taken by
Black’s pawn rather than letting the pawn
march farther and take a rook.
Think of this as a case where a pawn again
marched diagonally with a capture, enabling it
to deliver (or threaten) a fork that would not
have been possible on its original file. But in
order to move over a file, the e4 pawn needed
White to put something on d3 that it could
take; the something—White’s queen—was
drawn into place with a check (Qd3+).
Dg301: Black to move
Dg300: Black to move
Dg300: Here is a nice extension of the principle we are studying. Black examines every
check as a matter of course, and finds two:
Qe2 and Qd3. Qe2 loses the queen without
Dg301: Another extension of the principles in
this chapter. Black’s possible checks (Nc3,
Qf1, Qxc2) don’t seem to go anywhere, so he
experiments with captures and their consequences. Nxb2 is interesting because White’s
only way to recapture would be with his king;
any exchange that causes the king to move is
interesting. Now what do you see in the resulting position? The king and d2 rook are left
a square apart on the same rank, in position to
be forked by a pawn on c3. Black has no
pawn on the c-file. He does, however, have a
pawn on the b-file that is close by; if that
pawn could capture something drawn onto c3,
it could execute the fork. One way to get an
enemy piece onto a square, as we have seen,
is to put one of your pieces on the square in a
threatening way that requires the enemy to
recapture there. Best of all is a check. So
Black plays Qc3+, a move that attacks both
White’s king and queen; White has to play
QxQ (White’s king can’t capture the Black
queen because the queen’s square is guarded
by a pawn; and if White moves his king, his
queen gets taken with QxQ). After White’s
QxQ, Black plays b4xQ+—forking king and
rook with cover from Black’s own rook on c8.
Black in effect has traded a knight for a rook.
Again, see how the pawn was able to move
over to deliver a fork on a different file after
Black drew a White piece onto that file that
the pawn could capture.
Now remember that all this assumes White
replies to Black’s initial Nxb2 with KxN.
White doesn’t have to do that; he can skip the
recapture, and indeed is better off doing so—
in which case Black wins a pawn rather than
the exchange. It is another case where the
threat of an eventual fork, if appreciated by
both sides, leads to indirect gains.
2.5.5. Strategic Implications.
Now a few thoughts on the strategic implications of our work on pawn forks.
An easy way to get nailed by a pawn fork is to
allow one of your pieces to get trapped on a
square where it has limited motion. Bishops
and knights near the side of the board are especially vulnerable to this type of trouble; a
knight has a maximum of eight flight squares
when it is well-placed, but when it’s on the
side of the board it may have only four or
even fewer, and then it is easy for some of
those squares to be occupied by its fellow
pieces or to be under attack by the enemy.
Likewise, a bishop in the middle of the board
may be able to move in four different directions; but a bishop on, say, a5 with one of its
own pawns behind it on b6 can only go one
way, and has a maximum of four escape
squares. There are lots of ways for pieces
stuck in this way to be taken by pawns, either
directly (they simply get trapped) or by being
threatened in ways that force them to move
onto squares where they get forked.
There is additional reason to worry whenever
you see pieces being used as defenders of
other pieces—or of pawns. For then if the
man under attack gets taken, it is replaced by
a new valuable target that may be loose or
underdefended. When you do protect your
men with other pieces, remember that as soon
as the protectorate gets taken,you will be
forced to move the guarding piece onto a
square of your opponent’s choosing. There it
may become a target. It may be loose; it may
lack the defensive powers of the piece it replaced; it may have greater value than the
piece it replaced. Thus we saw a number of
examples in this chapter of exchanges where
pawns were taken and pieces performed recaptures—and then the pieces got forked.
Lesson: when you press a piece into service
protecting a pawn, give thought to the danger
that it can be drawn onto the pawn’s square
with a capture.
Since pawn forks often are the residue of exchanges initiated by pieces (a bishop takes a
piece and gets recaptured; then comes the
pawn fork), it follows that you can expect
better success with pawn forks when you have
a well-mobilized army—pieces on open lines
attacking lots of enemy squares and putting
pressure on enemy pieces. Those are the positions that give rise to exchanges that make
pawn forks and other double attacks possible.
Notice generally, too, that victims of pawn
forks often do not have good control of the
center of the board. For a pawn to fork two
pieces it often has to pass through the center
or be operating in a sector where it is more
advanced than the pawns on the other side
(otherwise the enemy pawns interfere with its
attacking movements). Pawns established in
the center are most likely to be in a strong
position to make or threaten forks because it
is easy for enemy pieces to gather on the same
rank in their own territory where enemy
pawns in the center can reach them.
Chapter 3:
The Discovered Attack.
3.1. Bishop Discoveries.
3.1.1. Introduction to Discovered Attacks
Generally.
In a discovered attack, or “discovery,” one of
your pieces moves out of the way of another,
unleashing attacks on two enemy pieces at the
same time—one by the unmasking piece and
one by the piece unmasked. The enemy only
has time to protect one of the threatened
pieces. You take the other one. The diagram
on the left shows the idea in skeletal form. If
White plays his knight to f6, it gives check
while unmasking an attack by his queen
against Black's queen. Black only has one
move to respond to these two threats, and he
has to spend it moving his king to safety.
Then White plays QxQ. This at least is one of
the patterns (a knight discovery) in its classic
form; there are many variations on the theme
that we will consider in due course.
Discovered attacks always involve two offensive pieces: an unmasked piece and an unmasking piece. Every piece has the power to
unmask attacks by others by moving off of
lines that it occupies. Not every piece has the
power to be unmasked, though; a knight, for
example, can't be unmasked because it can't
be masked in the first place: it jumps rather
than slides, so it doesn’t move along a line
that can be temporarily blocked by a fellow
piece. But the knight is a magnificent masker
and unmasker of attacks by other pieces.
Conversely, the queen is a great piece to unmask, but not a good masker of other pieces.
It can’t hide an attack by a rook or bishop
because a queen can make all the same moves
that either of those other pieces can; if a
queen masks a threat by a rook, it already
makes the same threat the rook would. The
essence of a classic discovered attack is that
before it is executed, neither piece directly
threatens anything. After it is executed, both
of them do.
The plan of this section will be to take each of
the major unmasking pieces—the bishop, the
rook, the knight, and the pawn—and study
one by one how they can unveil attacks by
other pieces: what the unmasking piece looks
like when it is poised to do this, how the germ
of such an opportunity can be created, and
how such ideas can be perfected and executed
once they come into view. We will identify
the visual patterns that signify the possibility
of a discovered attack and practice identifying
them until it becomes habitual.
Mastering discoveries means learning new
ways to think about the pieces and the relationships between them. You may be accustomed to thinking of bishops as pieces that
attack diagonally and to regarding rooks as
pieces that attack back and forth and from
side to side. That’s not wrong, but it’s incomplete. Bishops attack diagonally and unmask
vertical and horizontal attacks by rooks and
queens. Rooks attack vertically and horizontally and unmask diagonal attacks by bishops
and queens. Make it one of your goals to
think of your pieces not just as individuals but
as partners—as parts of a team whose efforts
need to be coordinated. Discovered attacks
are an example of coordination, as each partner makes the other more powerful; a bishop
and rook on the same file, with the former
masking the latter, often has far more destructive power than either piece by itself.
Every discovered attack starts with a kernel
consisting of two pieces: the piece to be unmasked and the piece that will unmask it.
Once found, a kernel can serve to organize the
rest of your thinking about what to do: you
start looking for targets for each piece or
ways to clear the lines between the pieces and
their targets. We will be studying discovered
attacks one kernel at a time: first the one
where the bishop masks a rook or queen on
the same file or rank; then the kernel where
the rook masks a bishop or queen on the same
diagonal; and so forth. We will emphasize
spotting the kernel of a discovery because the
practical importance of training your eyes in
this way is so great. If you don’t see the basic
pattern when it's there, all the skill in the
world at perfecting it won't be of much use.
3.1.2. Introduction to Bishop Discoveries
target needs to be an unguarded bishop or else
a protected piece that is more valuable, such
as the enemy queen (whether it's guarded or
not).
But now we're getting a little ahead of our
story. Let’s start by studying some positions
involving discoveries by the bishop in simplest form.
3.1.3. The Classic Pattern.
Dg302
We begin with discoveries where the bishop
unmasks an attack by a queen or rook running
up the board or from side to side. The position
on the left is a skeletal illustration. If White
moves his bishop to c4, it checks Black’s
king; the bishop’s move also unmasks, or
“discovers,” an attack by the White rook on
Black’s queen, which White will win next
move. The job of the piece in front is to give
check and thus keep your opponent busy; the
piece in the rear then has its chance to carry
out a capture. This is the typical pattern,
though there are others we will study later.
Before a discovered attack is unleashed there
always are three pieces in a line on a rank,
file, or diagonal: the masked piece, the piece
about to unmask it, and the target. When the
bishop is doing the unmasking, the three
pieces always are on a file or a rank. That is
the kernel to look for in the positions that follow: a bishop blocking the path of a rook or
queen. Then we'll follow up with standard
questions: whether the two pieces in the kernel both have good targets, or whether targets
might be created for them; whether the
needed lines are clear or can be cleared; etc.
We also can work toward discovered attacks
by thinking about the suitable targets for
them. Bishop discoveries always unmask attacks by queens and rooks. It follows that the
target of the unmasked piece usually needs to
be a queen or a loose piece for the attack to
turn a profit. Unmasking an attack by your
rook against a protected bishop, for example,
isn't going to scare your opponent; the rook's
Dg303: White to move
Dg303: We start with simple positions where
a discovered attack is ready to be executed:
one piece masks another, and both have good
targets. Visually most of these positions will
take a common form: a bishop moves from
the middle of the board to the edge near the
enemy king, where it gives check or makes a
capture; in the process it unmasks an attack
up the board by a rook or queen, usually made
from the back rank.
In the diagram to the left, notice the position
of White’s rook and bishop on the d-file—a
classic kernel of a discovered attack. The
bishop masks the rook; if it can vacate the file
in a forceful enough manner—e.g., with a
check—White will have the capture RxQ a
move later. So White plays Bxh7+; Black is
forced to spend a move protecting his king
with KxB; and now White takes Black's
queen with his rook. After Black recaptures
with RxR, White has traded a bishop and rook
for a queen and a pawn.
Dg304: Find the kernel of a discovery for
Black. His bishop on d6 masks the Black
queen’s path up the d-file.
pawn on h2 or h7 and thus giving check to the
castled king as we saw in the previous cases;
but as this position shows, you want to look
for every possible check you may be able to
give with the unmasking piece.
Dg304: Black to move
Meanwhile White’s queen is loose on d3. If
Black can use the bishop to give check, he
will be able to play QxQ afterwards. Black
thus finds and plays Bxh2+. White is forced
to play KxB (or NxB), and now Black takes
White’s queen. There were lots of ways to see
this move: the three pieces aligned on the dfile were a tipoff; or you might have set out to
examine every check, found only Bxh2, and
noticed that as a consequence of that move
the d-file would be opened—and also seen
that White’s queen is loose. Above all, however, study the relationship of the Black
bishop and queen here. The most important
thing about the bishop in this position is what
it masks.
Dg306: White to move
Dg306: The relationship between White’s
bishop and rook on the b-file should jump out
at you: never fail to notice when pieces are
paired like this, as it signals a possible discovery. Here White has a good target in
Black’s loose queen, so he looks for a check
he can give with his bishop and finds Bxf7+.
Of course the move is useless as a serious
threat to Black’s king, but its purpose is just
to create a distraction. Black has to capture
the bishop or move his king, and now White
plays RxQ.
Dg305: White to move
Dg305: An almost identical pattern seen from
White’s side. You notice that the bishop
masks the queen on d1; the queen otherwise
would be able to take Black’s queen, which is
loose. So White clears the bishop from the dfile and creates a distraction at the same time
with Bg6+. Black has to address the check;
after he takes White’s bishop, Black’s queen
is lost. The more common checking move in
this sort of position has the bishop taking the
Dg307: White to move
Dg307: The most important purpose of these
first positions is just to train your eyes to see a
single pattern: a bishop masking an attack by
a rook or queen on the same file. Here the
pieces are farther apart than before, but the
pattern is structurally the same. White’s job is
to move the bishop out of his rook's way violently—preferably with a check. Bg8+ does
the job: another example of a less usual
check, as the bishop attacks the king from the
rear. White will play RxR next move, winning
the exchange.
for a check or other violent move to give with
the bishop, and plays Bxf7+. However Black
responds to this check, White next plays RxR
and wins the exchange.
3.1.4. The Unmasking Piece Makes a Capture or Threat.
Dg308: White to move
It isn't always possible for the unmasking
piece to deliver a check, nor is it always necessary; any move that creates two threats at
once has winning potential. Here are some
positions where the unmasking piece makes a
capture or threat that serves the same distracting purpose as a check.
Dg308: Where does White have a possible
discovered attack? On the side of the board,
where we find the familiar kernel of bishop
masking rook on the same file. There is an
easy target: again Black has a loose rook, this
time on a7—a valuable enough piece to justify sacrificing the bishop if necessary. White
looks for a check the bishop can give as it
moves out of the way. He finds Bc4+, a nice
backward move that wins the loose rook
without need of a sacrifice.
Dg310: White to move
Dg309: White to move
Dg309: White has a bishop with a rook—
indeed, two rooks—behind it on the same file.
The arrangement signals the possibility of a
discovered attack. White has a fine target for
the rooks on c8. True, the rook there is protected by Black’s other rook at f8; but since
White has two rooks trained on the square, the
target is attacked twice and protected only
once and so is as good as loose. White looks
Dg310: In this first position, White's bishop
and rook on the c-file are in the characteristic
formation for a discovery, with Black’s loose
knight providing a suitable target. White just
needs to vacate the bishop from the file forcefully. The types of moves considered in the
previous section won’t work here because
White has no checks. But he has another violent move at his disposal: BxN, taking a
knight and threatening the rook on f8. Black’s
king isn't threatened, but he nevertheless must
redress his loss and protect his rook with
KxB—after which White can play RxN, winning a piece.
Dg311: Black's bishop masks an attack by his
queen against White’s loose knight on the efile. Black looks for things he can do with his
bishop that will keep White busy and allow
QxN a move later. The bishop has no checks
and no good captures; so Black considers eve-
rywhere the bishop can go, searching for a
threat.
Dg311: Black to move
He finds Bh3: not a check, but a threat against
White’s rook. White either loses the knight or
trades a rook for a bishop, forfeiting the exchange.
When you launch a double threat without a
check at either end of it, as Black does here,
you have to be especially careful to think
about your opponent’s options in reply. Since
you haven’t given check he will have a freer
hand than he otherwise would; maybe he can
give check, wrest away the initiative, and escape your attack. In this case Black needs to
notice that White has a check available in
Qa4. Is this trouble? No, because Black can
meet it with b7-b5. But the point still holds:
don’t go forward with a tactical sequence —
especially one that doesn’t give check —
without considering checks your opponent
can throw at you in the middle of it.
Dg312: White to move
Dg312: The same idea in slightly different
visual form. White's bishop and rook on the dfile, of course, create a possible discovery
against Black’s loose bishop. To unleash it
White needs a violent and distracting move
for his own bishop to make. As the piece can't
give check or make a good capture, White
looks for threats the bishop can make and
sees that it can attack the rook on b6. There
are two ways to do it: Bc5 or Bc7. Which is
better?
Answer: Bc7 is better. In reply to Bc5 Black
could play Rb7, both moving the rook to
safety and using it to protect the bishop on d7.
Bc7 not only threatens Black’s rook and
bishop at the same time, but also makes Rb7
an ineffective reply. White wins the bishop.
Notice the general point, though: you always
want to be mindful of any way the enemy
might be able to move the target and address
your other threat in one stroke.
Dg313: White to move
Dg313: You see White’s bishop masking his
rook; you see that the rook would attack
Black’s queen if unmasked; you look for a
move by the bishop that would take advantage
of the situation. The bishop's only capture,
Bxh6, would be of no great concern to Black.
But look as well for threats White can make
that would have to be taken seriously. Again
White can use the bishop to threaten Black’s
rook, this time with Bf4. After Black moves
his queen to avoid RxQ, White takes the rook
and wins the exchange.
Most often the point of a discovered attack is
that the unmasking piece—the bishop in these
examples—is sacrificed or creates a timeconsuming threat so that the unmasked piece
can capture an enemy target. But here the
unmasked piece (the rook) creates the time-
consuming threat, effectively allowing the
unmasking bishop two moves: one to line up
against Black’s rook, and the other to take it.
Whichever piece plays the primary attacking
role, the logic of the tactic is the same: you
launch two attacks at the same time, leaving
your opponent time to deal only with the
more pressing of them. Soon we will give
more detailed consideration to the most important positions where the stationary piece
does the distracting and the unmasking piece
does the attacking: the discovered check.
Note that you want to consider all the ways
White could reply to the mate threat—and
especially any replies that also take the White
queen out of harm’s way and thus blunt both
ends of the fork. Here White could respond to
Bg1 with Qh3; suddenly neither part of the
fork works. But Black still wins because now
the d-file is clear for him to play RxR.
This position involves an important type of
threat to remember: a threat not against a
piece, but against a vulnerable square next to
the king. When you have a piece aimed at a
square adjacent to the enemy king, aiming
another piece there may create a threat of
mate; and if it does, that square can become a
target just as sensitive as the king itself.
3.1.5. Drawing the Enemy King into Place.
Dg314: Black to move
Dg314: Black’s bishop masks his rook on d7,
and the rook is aimed at White’s queen. What
can he do with the bishop that will require a
time-consuming reply from White? He has no
checks or captures, so he looks for threats
(and of course you would want to look for
threats even if there were a capture to make;
the threat might be the better move). With no
White pieces on dark-colored squares, the
bishop’s prospects for threatening anything
may seem dim. But your assessment of a position always should include an inspection of
the enemy king and the pressures bearing on
it—the constraints on its movement, and its
exposure to checks. Black has a single check:
Qxh2. By itself that move wouldn't be productive, because the queen would have no
protection against KxQ. If the bishop could
add pressure to the h2 square, though, the
possibility of Qxh2 would become a mate
threat. Is there a way for the bishop to attack
h2? Yes, with Bg1. Of course White escapes
mate with KxB, but mate isn't the goal; the
goal is to require Black to address the threat
of mate and thus create time for the point:
RxQ.
What do discoveries look like when they lie
two or three moves away? For openers, consider that a working discovery requires two
enemy targets: one for the unmasking piece to
threaten to create a distraction (ideally the
king), and one for the unmasked piece to capture after the distraction does its work. In the
positions to this point both of those targets
have been in place from the beginning. Now
let's see some cases where one of the targets
needs to be drawn onto place.
The best target for a piece that unmasks a
discovered attack is the enemy king because a
threat to it must be addressed by your opponent and his options will tend to be limited
and safe for you. The king usually can’t escape the check by running off to protect the
other piece you are threatening or by inflicting a threat of its own. It moves too slowly.
So when you have some of the ingredients of
a discovery in place, it’s worth some trouble
to try to get the king into position to be
checked by the unmasking piece. The most
common ways of moving an enemy king are
by checking it with another piece or by capturing a piece that the king protects.
Dg315: In the example, White has the queenbehind-bishop kernel of a discovery in place,
with Black’s queen ready to be taken on d5 if
White can find a big enough threat to make
with the unmasking piece. Since White is
going for Black’s queen (and since moving
the bishop exposes White to the risk of QxQ),
the threat the bishop makes needs to be
against Black’s king to be effective. Can the
bishop give check?
els on the light squares and the king is on a
dark one. Again, try handling this by checking
the king with another piece, thus forcing it
onto a light square where it can be checked by
the bishop. Black can give check with his
rook in two ways: Rd2 and RxB. After Rd2+
White can move his king to, say, g1 with
nothing accomplished for Black. But in reply
to RxB+ Black has to recapture KxR —
moving his king onto a light square. (If White
instead moves his king, Black plays RxQ — a
skewer.) Now Black checks with Bd3+, unveiling a threat against White’s queen that
White has no time to fend off.
Dg315: White to move
No, not yet; White’s bishop travels on the
dark squares, and the king is on a light one.
So the first thing to consider is giving check
with another piece in hopes of forcing the
king onto a square where it can be checked by
the bishop. White has one check he can give
without ruining the discovery he is planning:
Rh8+. Black would be required to play
KxR—moving his king onto a dark square.
Now White can check with BxR+; and after
Black plays KxB, White has QxQ.
Dg316: Black to move
Dg316: Black has the makings of a discovered attack on the f-file, where his bishop
masks the capture QxQ. If only the bishop
could vacate f5 and attack White’s king. At
the moment it can’t be done; the bishop trav-
Dg317: Black to move
Dg317: Black has the kernel of a discovery on
the d-file: his bishop masks his queen, which
otherwise could take White’s queen. White’s
queen is defended by its king, however, so
QxQ would not yet be profitable. And there is
another problem: What unmasking move
could Black play? We look first for a check
the bishop can inflict and find Bb4, but one
always must consider what the reply to such a
move would be; sometimes your opponent
will have an answer that fends off the check
and the unmasked threat. This is such a case:
Bd2 would stop both of Black’s threats. (Another possible sequence would be 1. …Bb4+;
2. a3xB, QxQ; 3. KxQ, Nxf2+ (a knight fork);
4. Ke1, Nxh1; 5. Bg2 (where the knight has
no escape)—and White is okay, as he has won
a queen and two pieces in trade for a queen,
and pawn, and a rook.)
Still, for Black to have the kernel of a discovery in place like this, with the enemy queen at
one end of it, is an opportunity not to be
abandoned lightly. Black looks for ways to
move the White king by checking it with his
other pieces and finds none. But there is another way to force a king to move: capture
something on a square next to it—a square
only the king protects, so that it has to move
to recapture. Nxf2 comes to mind, as it not
only captures a pawn but forks White’s queen
and rook. Suppose White then plays KxN.
Now how would the board look? The bishop
on d6 would have a check with Bxg3+, and
this time there would be no way for White to
defend against it while also protecting the
queen—which would have been left loose
when the king moved away. So now the discovery works.
The discovery would work better, and would
indeed look like many good discoveries we
have seen, if a more valuable piece—i.e.,
Black’s queen—could be made the target of
the unmasked rook. The method for arranging
this is simple: when you are confronted with
an unsuitable target like the d7 knight here,
ask whether you can first take it with another
piece and what the consequences would be.
Here White can capture with BxN; Black’s
only recapture is QxB. If Black goes through
with that move, the exchange has caused the
bad target to be replaced with a good one.
Now Bxg7+ unmasks a classic discovered
attack against Black’s queen, which is lost
after Black fends off the check.
3.1.6. Drawing the Target into Place.
Suppose your unmasking piece is one move
away from giving check or inflicting some
other terrible threat; the problem is that the
masked piece has nothing suitable to attack.
Perhaps the target at the other end of the file
is protected, or not very valuable. Again,
there are some standard ways to try to draw a
good target into the path of the discovery.
Dg319: Black to move
Dg318: White to move
Dg318: In the diagrammed position here,
White has the kernel of a discovered attack on
the d-file. The bishop has a good threat to
make: Bxg7 gives check. But the rook behind
it lacks a good target once it is unmasked. It
can take the knight on d7 (and avoid being
recaptured because it would have cover from
the bishop on b5); but meanwhile the White
bishop would have been sacrificed, so the net
gain for White would only be the pawn on g7.
Dg319: Black has the kernel of a discovery on
the d-file: the bishop is poised to give check
with Bxh2 and unmask an attack by the rook
at the same time. But an attack against what?
The only target on the d-file is White’s pawn,
which anyway is protected. Again, in this
situation consider whether you can take the
bad target with one of your other pieces, and
so cause it to be replaced by a valuable one.
Here Black can take the pawn with his bishop,
which after Bxd3 threatens both White’s
queen and his rook on f1. White has to play
QxB if he wants to avoid losing the exchange
to BxR—but after QxB, the board is arranged
for the discovered attack Bxh2, sacrificing a
second bishop to win the queen.
Dg320: Spotting the kernel of the discovery
for Black on the d file should be habitual by
now. The challenge is to diagnose and cure
the impediments to its success. The first is
that the bishop on d6 lacks a good threat; it is
aimed at h2, where it could give check, but its
path is blocked by its fellow knight. The second problem is that the rook on d8 lacks a
good target.
Dg320: Black to move
If the bishop were vacated from the d-file, the
rook would be directed at White’s bishop,
which is guarded. Once you clearly understand these obstacles, ideas for getting rid of
them at the same time suggest themselves:
move the Black knight out of the bishop’s
way, and in the process use it to capture the
unsuitable target on d3 and cause it to be replaced by something better. Thus NxB, and
now if White wants to avoid the loss of the
piece he has to recapture QxN. Now both
problems have been solved. The Black
bishop’s path to h2 is open, and Black’s rook
has a good target in the queen on d3.
think about what it would take to make the
tactic work. (a) First, the pawn on c7 would
need to be replaced by a better target. So consider taking the bad target with one of your
other pieces (like the White knight on b5),
and ask whether your opponent would have to
recapture with a more valuable piece. (b)
Second, it would help to have a better target
for the unmasking bishop to threaten—
preferably Black’s king, which unlike its
queen would not be able to move and cause
trouble when attacked. Black’s king is behind
its queen, but the queen protects the same
pawn on c7 that we are trying to trade for a
better target. The solution to the problems at
both ends becomes obvious: White plays
Nxc7; if Black recaptures QxN, White has a
check for his bishop with Bxe6 and a target
for his queen in the loose Black queen on c7.
The lesson repeats: be clear about what obstacles prevent your idea from working; often
two problems can be solved with a single
stroke.
3.1.7 Clearing Needed Lines.
In the last two positions the discovered attack
required a preliminary exchange that both
improved the target the unmasked piece
would attack and opened a line for the unmasking piece to use to make a threat against
the enemy king. We now look more closely at
this last principle: identifying lines that need
to be opened to make a discovery work, and
clearing them with exchanges and threats.
Dg321: White to move
Dg321: Where does White have the makings
of a discovered attack? On the c-file. But once
more only the queen-behind-bishop kernel is
there; the queen lacks a good target, and the
bishop has no checks to give, although it can
attack Black’s queen with Bxe6. So again
Dg322: White to move
Dg322: In the diagram position, start the standard identification of the kernel discovery.
Here it's on the d-file, where White's rook is
aimed at Black’s queen at the other end of the
board. The difficulty—both in seeing the kernel and in perfecting it—is that White has two
bishops in the way. If one of the bishops
could be cleared from the file in a manner that
is time-consuming for Black, the board might
be set up for an effective discovery by the
bishop that remains. Each bishop has a possible threat (try imagining the board with one of
them removed, then the other): the d3 bishop
can go to c4 and threaten Black’s rook on a2,
and the d4 bishop can capture Black’s knight
on f6 and threaten to take another piece from
there. So first White plays Bc4, requiring
Black to respond by moving the rook to a8 or
perhaps a5; and now the way is clear for
White's other bishop to play BxN. Black has
to spend his reply move saving his queen (this
is one of those discoveries where the threat by
the unmasked piece is greater than the threat
by the unmasking piece).
Notice that after White plays BxN, Black
could try to take the offensive by playing his
e7 bishop to c5—a move that seems to expose
his queen to capture, but actually is quite safe
because it gives check (when White played
BxN, he created an open diagonal to his own
king). Now if White moves his king, Black
can play QxBf6; in other words, the Black
bishop's move to c5 was another discovered
attack. But White has an answer: he can block
the check and save his piece by simply retreating his bishop to d4, having already won
a piece. We see again a recurring point: don’t
forget to look for checks you opponent might
be able to throw into the middle of the sequence you are planning. They can ruin your
plans by buying him time to move his pieces
out of harm’s way. It’s not a problem here,
however, because White has an excellent answer.
Now think about one other way things could
go. Black could respond to the initial move 1.
Bc4 by moving his queen to a8 to protect his
rook; his plan this way would be to lose just
the exchange rather than a whole piece. But
play it through in your mind’s eye: White
plays 2. BxR; Black replies with QxB; but
now the queen ends up in cramped territory,
which should worry Black. What happens if
White throws an attacker at the queen with
Ra1? The queen turns out to have nowhere
safe to go. So Qa8 as a first response for
Black doesn’t work out. Again, though, the
important lesson is general: if you attack an
enemy piece as part of a double threat, realize
that he might be able to reply by adding to its
protection as well as by moving it. If he does
add to its protection, imagine going ahead
with the capture and permitting him to recapture, and ask how the board would then look.
Obviously this practice would be just as important if you were playing the Black pieces
here; else you might lose your queen.
Finally, let’s return to the initial diagram to
emphasize the most basic point of the position: if you see the skeleton of a discovered
attack but with extra pieces in the way, think
about how you might clear the obstructions in
a forcing manner that cuts down your opponent’s choice of replies—i.e., with checks,
captures, and threats. Here a simple one-move
threat by the d3 bishop forced Black’s reply
and made possible a classic discovered attack.
More broadly the position shows the importance of seeing the kernel of a discovery even
when there are other pieces also cluttering the
line.
Dg323: White to move
Dg323: White’s bishop masks an attack up
the d-file; this time the potential attacking
piece is White’s queen. White’s bishop has an
obvious place to go that will cost Black some
time: Bxh7+. The problems are that Black’s
queen—the natural target of the operations—
is guarded by a knight, and that the Black
pawn on d4 blocks the d-file. Start with the
second problem; examine how the pawn is
threatened and defended. It is attacked by
White’s c-pawn and two knights, and defended by a knight, a bishop, and a queen.
Play through the liquidation of those pieces in
your mind’s eye and see what is left at the
end: 1. c3xd4, Nxd4; 2. NxN, BxN; 3. NxB,
QxN. With the board thus simplified, what
would be possible? The c and d pawns would
be gone; both of White’s knights would be
gone; Black’s knight and bishop would be
gone; and Black’s queen would be loose on
d4, in front of White’s bishop—a classic
setup for a discovered attack via Bxh7. After
Black plays KxB, White plays QxQ, winning
Black’s newly loosened queen.
This position looks a little complicated because it involves several exchanges, but its
structure is simple. Once you see the formation for a discovered attack, you just methodically work through all the exchanges bearing
on the obstructions that prevent it from working. This example illustrates a particularly
useful version of the idea: when an enemy
pawn blocks a discovered attack against a
piece that lies behind it, perhaps the piece you
want sooner or later can be made to replace
the pawn if the pawn is taken. That is what
happened here: the d4 square never was emptied; rather, the pawn eventually was replaced
by the target of the exercise—the queen. But
to get to any of this you first have to see the
basic pattern for a discovery on the d-file
without being blinded by the obstacles in the
way.
Of course if Black sees all this coming he will
simply forfeit the pawn at the beginning
rather than head down the road toward larger
losses by making a recapture; he will notice
the kernel of a discovery for White and will
realize that d4 is a square of danger.
This position is a good study in the value of
playing through a series of liquidations in
your mind's eye. The particular type of liquidation shown here is fairly common: a pawn
near the middle of the board often will be
protected and defended several times, making
it important to understand what would happen
if all those potential captures and recaptures
were played out.
Dg324: White has the makings of a discovered attack on the g-file, of course, where his
rook and bishop are in the standard formation.
White looks for a violent, time-consuming
move he can make with the g2 bishop and
finds—nothing. BxB is met by QxB with no
gain; Bf3 just loses the bishop.
Dg324: White to move
Still, a discovered attack pattern with a rook
aimed at the enemy queen is an important
opportunity, so White looks for other moves
he could make that would create a target for
the g2 bishop. It would be ideal if the bishop
could check Black’s king. Where would it
need to go to do that? To d5. What stands in
the way? Black’s bishop at e4. That bishop
cannot be captured, but it can be threatened
with Qc2, Qd3, Qd4, or Qd5. Qd5+ is most
interesting because it checks Black’s king and
so requires immediate attention. Black would
have to either move the king or take White’s
queen. If he moves the king, White plays QxB
(and if Black then plays QxQ, White has
BxQ). So Black will play BxQ. Reconsider
the board as it then would appear: the same
potential for a discovered attack would exist,
and now the White bishop’s path to d5 would
not be blocked by Black’s bishop; Black’s
bishop would be on d5. So White plays
BxB+, and Black replies Kh8; and now White
has RxQ. He has exchanged queens and won
a bishop.
You might also have considered starting with
Qd4. It looks safer because it doesn’t expose
your queen to capture by Black’s bishop, but
still attacks the bishop a second time; and it
creates the threat of mate with Qxg7. But Qd4
has the major disadvantage of not giving
check. A key difference between giving check
and creating a mate threat is that a mate threat
doesn't force such a narrow range of replies
on your opponent. He may be able to address
it by giving a check of his own that seizes the
initiative. In this case Black can respond to
Qd4 with Rxa2+. White has to reply KxR—
and then comes another check from Black:
Ra8. Since White has nowhere safe to move
his king, he has to interpose his queen on a7
and lose it next move to RxQ. Then White has
the recapture BxR, but that wasn’t exactly
what he had in mind at the outset. Remember:
if you resort to threats that don’t give check,
you have to consider any checks (and any
successions of checks) your opponent might
be able to use to interrupt your plans.
Dg325: Black to move
Dg325: Where does Black have the makings
of a discovered attack? Actually in two
places: on the c-file and on the h-file, where
his knight masks his queen. Since we are focusing here on discoveries by bishops, start
by working with the threat on the c-file. The
rook on c8 is poised to take White’s queen if
the bishop can be vacated from c5 in a forceful enough way. But where can it go? The
first thing to consider is whether the unmasking piece can give check. That’s not possible
here, both because the king is on a light
square and because the pawn on f2 blocks the
bishop’s path to the back rank. But when you
see an obstruction like the f2 pawn, ask what
you could do if it were gone. If the pawn
weren’t there, Black could play Bg1. Does
that qualify as interesting? It should, for then
the position begins to look a lot like one we
saw a few frames ago; the bishop would be
attacking a square adjacent to White’s king at
which his queen also would be aimed.
An idea thus emerges: if Black could get his
queen aimed at h2 and get the f2 pawn out of
the way, then Bg1 would threaten mate and be
an effective discovered attack. The Black
queen’s path is blocked by the Black knight
on h5, but the knight can evacuate its square
with check: NxB+. If White replies f2xN (the
h-pawn can't be used because it's pinned),
now Bg1 is possible and threatens both
Qxh2# and RxQ.
By the way, notice that White can reply to
Bg1 with Bc4, limiting his immediate losses
to a piece. White’s queen then protects h2
against a mating attack, since the White pawn
and piece on the second rank suddenly are
both gone. After Black plays RxBc4, White
slides the queen over to e2, where it is safe
and still foils the mate threat.
In a later chapter we will study knight discoveries like the one that unmasked the Black
queen’s attack on h2, but already you can see
how the train of thought might have started
there just as easily: the knight in front of
Black’s queen can move out of the way with
check (NxB+). Black imagines the board as it
would look after the recapture f2xN, and recognizes the same sort of idea we saw earlier:
his bishop can unmask an attack against
White’s queen, and at the same time add a
second attack on the pawn in front of White’s
king by moving to g1.
Dg326: White to move
Dg326: White's bishop and queen are characteristically arranged for a discovered attack,
with Black’s loose queen making a fine target
on d4. Everything is prepared except a good
threat for the bishop to make when it vacates
the d-file. It would like to give check, naturally, but its lines to the king from b5 and g6
are blocked. What to do? When your goal is
to clear a line, consider attacking pieces that
are guarded by the pieces you need to move.
Here the lines that White's bishop needs to
give check are blocked by Black’s d7 bishop
and f7 pawn. If White can capture something
that one of those pieces protects, then the
piece will have to move to recapture, a line
will be cleared, and perhaps White can win
Black’s queen with a discovery. As it happens, both of Black's blockers protect the
pawn on e6, and White can take it with
Rxe6+. Now if Black recaptures by any
means, he opens a diagonal leading to his
king, and White has a discovery that does win
the Black queen on the next move—either
Bb5 or Bg6. Obviously Black can capture the
bishop easily either way, but you don't care;
you just want to make him spend a turn that
way so you can take his queen.
In practice, seeing all this just gives White a
way to take a Black pawn for free (and improve his position a bit), since Black would of
course rather lose the pawn of e6 than his
queen; if he is attentive—and you should assume he will be—he will reply to the capture
by moving his king to f8, not by recapturing
and setting himself up for the discovery.
Many of the positions we are studying work
that way. In practice they yield a payoff, but
not necessarily the first and best one you say;
for your opponent may see the coming disaster and choose to make some lesser sacrifice
to avoid it.
Dg327: Now consider how these ideas can
look when you’re playing defense. The two
sides are fighting for control of the center;
Black would like to get rid of one of White’s
central pawns. He attacks the pawn on d4
twice (with his queen and knight), and it is
defended just once (by White’s knight). So
should he take it with Nxd4?
Dg327: Black to move
It is important to visualize such sequences and
consider what would be possible on the board
as it would look afterwards. Picture 1.
…Nxd4, 2. NxN; QxN. The implications of
the resulting position are clear if you notice
the kernel for a discovered attack that White
has on the d-file all along. That kernel is reason for Black to act with great care in any
operations on that file; taking the d-pawn is
asking for trouble, because it creates a target
for White’s queen after it is unmasked. In this
case the bishop on d3 would end up able to
give check with Bxb5, winning Black's queen
on d4 next move. So Black dares not play
Nxd4 in the first place after all.
Notice how those quick exchanges on d4
ended up leaving White with a new way to
check Black's king and also with a great new
target for his queen to take once it's unmasked. An earlier point repeats: when a contested pawn lies in the center, don't just ask
who has more pressure against it. Ask what
the board would look like after those pressures are spent.
3.1.8. Horizontal Discoveries.
Thus far we have been considering positions
based on a single root idea: a bishop masking
an attack by a queen or rook on the same file.
The masked piece travels vertically up the
board after the bishop vacates its square. But
of course bishops also can unmask attacks by
pieces on the same rank—attacks that are
horizontal, with the unmasked piece running
sideways across the board. These are some-
what less common than vertical bishop discoveries; it is easier to arrange a vertical discovery because it's easy for a queen or rook to
move from their starting positions on the back
rank onto open files where bishops sit—and
then to travel up the files once the bishops
move out of the way. A horizontal discovery
usually requires that a rook or queen get out
toward the middle ranks of the board first so
that it can then travel sideways productively.
At any rate, the logic and mechanics here are
no different than in the positions we already
have studied. The main new challenge lies
just in spotting a new kernel: the rook or
queen alongside the bishop on the same rank,
rather than behind it.
Dg329: White to move
Bh6+ doesn’t work because the queen can
both dissolve the check and take itself out of
danger with QxB. Be5+ is better because it
threatens Black’s king from a square the
queen can’t reach, so the queen is lost one
way or the other. If Black plays f7-f6, White
replies RxQ; if Black plays Qf6, White has
BxQ.
Dg328: White to move
Dg328: In the example, where does White
have the makings of a discovered attack? His
bishop on c2 masks nothing on its file, but on
the second rank it masks an attack by the
White queen against Black’s rook. From here
the thinking is familiar. The bishop must vacate the rank violently, and this it does with
Bxh7+. After Black fends off the check with
KxB, the way is clear for White to play QxR.
White wins the exchange and a pawn with a
simple discovered attack turned on its side.
Dg329: Find the kernel of a horizontal discovery for White. He has his rook "behind"
(i.e., masked by) his bishop on the fourth
rank; he has a good target for the rook in the
Black queen on h4; and he has a check to give
with his bishop—two of them, in fact: Bh6+
and Be5+. Which is better?
Dg330: White to move
Dg330: This time the search for the basis of a
discovery leads you to the first rank. Black’s
queen appears to have pinned White’s bishop
to his rook; but if the bishop can vacate the
rank forcefully enough, White can turn the
tables and play RxQ. Indeed, everything is in
place for a discovered attack except a suitable
threat for White’s bishop to make. It can’t
now threaten Black’s king; the bishop travels
on dark squares and the king is on a light one.
But you see that by moving to h6 the bishop
could line up behind the White queen already
aimed into the king's territory. This cries out
for consideration of QxR, both as a climax
later and as a preliminary table-setting move
now. Or you might come at the position from
the other direction by just looking for checks
you can use to move the king into a vulner-
able position. White has two: Qxf7 and QxR.
Qxf7 still leaves the king on a light square
after KxQ. But if White instead plays QxR,
the recapture KxQ leaves the king on f8. Now
the c1 bishop would be able to give check
with Bh6+; White next plays RxQ, taking the
queen and netting a rook with the sequence.
Dg331: Find the kernel of a discovered attack
for Black. He has the queen-behind-bishop
pattern horizontally on the sixth rank. He has
a target, too; he could play QxQ for free if the
bishop on b6 were out of the way.
Dg331: Black to move
Again we have a clear view of the problem;
we need something violent and distracting for
the bishop to do—probably a check, but at the
moment the bishop can’t threaten White’s
king, which is on a light square. We need to
move the king. We even can see where: if it
could be forced onto g1, Black could play
BxB+ and win the queen. The methodical
way to pursue this is by experimenting with
checks using Black’s other pieces. There is
just one to consider: Rxh2+. How would
White respond? He has two legal moves:
Kg1, which is what we want, or KxR, which
is more likely and doesn’t immediately help
us. Okay; but imagine the position after KxR;
look for you next check. The only piece that
would have the power to check would be the
queen. Qh6+ gives check while still staying
on the sixth rank and preserving the kernel of
the discovery. White’s only legal move this
time is Kg1, and then the discovered attack
BxB+ works to win White’s queen.
Dg332: Black to move
Dg332: Where does Black have the makings
of a discovered attack? On the fourth rank.
This pattern is easy to overlook during a game
because of the pawn that lies between the
Black queen and bishop. It's still important to
see the kernel; teach your eyes to hop over
pieces or pawns in the way of the pattern,
since it may be possible to get rid of those
obstructions, as is our challenge here. Black
has a target in White’s queen on a4, and he
has a check for the bishop in BxN+. All the
ingredients are in place save one: the pawn on
c4 must be removed. The usual way to clear
an enemy pawn from a line you need is to
capture something it protects, forcing it to
move to recapture. Black does this with Nxd5.
White can’t recapture with his c3 knight because it’s pinned; and if he plays c4xN, the
way becomes clear for BxN+, discovering the
fatal attack QxQ. Of course White should
prefer just to forfeit the pawn.
There remains one complexity to consider:
White could reply to Nxd5 with QxB. (Don’t
automatically assume that a capture will provoke a recapture; it might provoke a fresh
capture by your opponent elsewhere.) Of
course this would leave White’s queen open
to capture by the knight now on d5, but it also
would unpin the knight on c3 and thus ready
it to capture Black’s queen next move. So
does White’s QxB ruin Black’s plans? Not
quite. Imagine it playing out: 1. …Nxd5; 2.
QxB, NxQ; 3. NxQ. When considering a little
sequence like this that would reposition either
or both of your knights, pause to consider
whether there might be a kicker at the end in
the form of a knight fork. Here the exchanges
just described would leave a Black knight on
b4—and able to drop next move to c2, where
it forks White’s king and rook.
Dg333: Black to move
Dg333: Here is a demanding position. A habitual scan for discovery kernels for Black
makes the lineup on the d-file obvious, but
nothing productive can be made of it because
the target (the d4 knight) is secure. Less obviously, though, Black has a kernel of sorts in
horizontal form on the sixth rank. There are
no pieces blocking the path between queen
and bishop, and the bishop has a check with
Bxh2. The missing ingredient this time is a
target: Black’s queen has nothing at all to
attack once it is unmasked. How might Black
somehow force or attract a White piece onto
a6, b6, or c6? Consider Black’s other pieces
and what moves they can make that might
help. The rook can’t force anything useful,
but now have a look at the bishop on c8. One
way to attract an enemy piece onto a square is
to put one of your pieces there in a manner
sufficiently threatening to make your opponent capture it. Here Black can put the c8
bishop onto the sixth rank with Ba6, where it
attacks White’s queen. What response could
White make? Moving the queen seems out,
because that would expose the rook on f1 to
capture; and letting the queen be captured
likewise is out. Another option would be Nb5,
where White interposes a piece between his
queen and Black’s bishop. But then Black has
c7-c6, attacking the knight and winning a
piece. (Once on b5 the knight is pinned to the
queen.)
That leaves White with one other reply to
Ba6: capturing the bishop with QxB. But this
completes the three-piece kernel of a discov-
ery on the sixth rank, setting up the board for
Bxh2+—a discovered attack that takes
White’s queen. Black ends up exchanging two
bishops for a queen and a pawn. (Moving the
queen, and enduring the loss of the exchange
with BxR, would have been better after all for
White.)
Seeing this idea will be easier after you have
studied skewers, for then your attention would
be attracted from the beginning by the alignment of White’s queen and f1 rook. You
imagine running a piece through them with
Ba6, see that this results in QxB, and then
recognize the three-piece pattern for a discovery that would result on the sixth rank.
Notice what has been involved in each of the
positions we recently have considered: (a)
Identification of the basic kernel for a discovered attack by the bishop. (b) A precise grasp
of the elements of a discovery that are in
place and those that aren’t—a suitable target
for the unmasking piece, a suitable target for
the unmasked piece, and clear lines between
all the relevant pieces. (c) Methodical thought
about how any obstacle or missing element
might be remedied. If the problem is that the
unmasking piece lacks a good target, we consider ways of drawing the king into its range:
checking the king with other pieces, sometimes repeatedly, or capturing something next
to the king and thus forcing it to move to recapture. If the problem is that the unmasked
piece lacks a good target, we consider ways of
creating one: if there are unsuitable targets
already in place, we might capture them with
other pieces and invite recapture by more
valuable enemy pieces; if there is no target in
place, we think about putting our own pieces
where we want an enemy piece to go and inviting capture of them there by making a
threat. Or perhaps we can threaten an enemy
piece that has limited movement and force it
to jump onto the rank and file where the kernel for a discovery is in place.
Finally, if the problem is that there are pieces
blocking the needed lines to make the discovery work, we have methods for dealing with
that as well. If the obstructing pieces are our
own, we look for ways to vacate them from
their squares that are violent and timeconsuming for our opponent: checks, captures, and threats. If the obstructing pieces
belong to our opponent, we may be able to
capture them and cause them to be replaced
by the targets themselves. Or we may be able
to draw them out of the way by capturing
pieces they protect, or by making threats from
squares they protect.
stationary, unmasked piece. After the king
avoids the check, the unmasking piece gets to
make a second move—perhaps a capture or a
retreat after a capture already made. This rearrangement of power between the masking and
unmasking pieces makes the discovered check
especially devastating, because it means that
the unmasking piece in effect gets to make
two consecutive moves unmolested.
That is not a complete catalogue of problems
that arise in creating discoveries and options
for dealing with them, but it is a summary of
the most common types. You want the
thought processes involved in those sorts of
sequences to become second nature so that
you see them right away and can spend your
tactical time thinking about more complicated
things: how these ideas might be combined,
or combined with other tactics; and how they
might come into view after a series of preliminary threats or exchanges. We will return
to all of these patterns, and explore and reinforce them further, when we examine discoveries by other pieces in the following chapters.
This section starts with simple one-move discovered checks, then shows how the methods
examined earlier in the chapter apply in this
setting. In addition to discovered checks, we
also will be looking at a few other patterns
where the unmasked, stationary piece provides the distracting threat (even if not with a
check) and the unmasking piece does the
damage. In all cases you still are looking for
the same kernel: a bishop masking a rook or
queen. What’s new here is that you may need
to draw the king into position to be attacked
by your stationary piece rather than your mobile piece; and when you create a target for
the mobile piece, you think a little differently
because you have greater liberty: you look for
ways to exploit the special opportunity to
make two unfettered moves with the same
attacker. The examples will make all this
more concrete.
3.1.9. Introducing the Discovered Check.
Think of how pleasant it would be if you were
allowed from time to time to make two consecutive moves without interruption by your
opponent. You could use the first one to bring
your bishop in position to attack the enemy
queen, then on the next move play BxQ. Or
you could use the first move to capture a protected enemy piece, and then use the second
move to retreat before being recaptured.
These marvelous possibilities are realized in
the form of attack known as the discovered
check.
Dg334: White to move
We have seen that in a usual discovered attack the unmasking piece is sacrificed or otherwise creates a time-consuming threat —
often a check — so that the unmasked piece
can capture something on the next move. A
discovered check reverses the pattern: the
move by the bishop or other unmasking piece
exposes the enemy king to a check from the
Dg334: In the skeletal position we have the
idea in simplest form. White has the kernel of
a discovered attack on the c-file. If the bishop
moves, Black’s king is in check and will have
to move, allowing the bishop to make a second move. The bishop’s target, of course, is
Black’s queen. The bishop has two ways to
attack it: Bg8 and Bd3. Either way the queen
is lost. If Black moves his king, White plays
BxQ; if (in reply to Bg8) Black plays Qc2,
White has RxQ.
It’s a light-squared bishop, so look for a threat
against something on a light square. The
choice target turns out to be Black’s bishop
on b7, because it's loose; if White can reach it
in two moves he will take it for free. White
thus plays Ba6+. After Black fends off the
rook check, BxB wins the piece.
Dg335: Black to move
Dg335: The kernel of the discovered attack
for Black on the f-file should be evident
enough. It also should be plain that this is a
setup for a discovered check. Black can exploit the pattern by plotting a two-move
course for his bishop. Look for White pieces
that, like the bishop, are on dark squares. The
queen always is a preferred target. Bd4+ attacks it, and BxQ takes it a move later after
White moves his king out of check.
Dg337: Black to move
Dg337: Notice the kernel of a discovered attack for Black: the bishop in front of the rook
on the f-file. If the bishop moves, the rook
attacks White's king; that makes this a case of
discovered check, giving the bishop two
moves to make trouble. It’s a light-squared
bishop, so look for a good White piece on a
light-colored square that it could attack—and
find the queen. The bishop needs to attack it
in one move and take it with the next. The
answer thus is Bxc2, again winning the queen
either by BxQ, or (if the queen moves to
block the check—an important possibility to
remember) with RxQ.
Dg336: White to move
Dg336: You first see the bishop-in-front-ofrook pattern on the e-file, and then that once
the bishop moves Black will find himself in
check. This means the bishop in effect can
have a free move, because after it moves
once—and almost regardless of where it
goes—Black will have to address the threat
against his king by moving it or interposing
something in front of it. So think about where
the bishop could go on its next move that
would allow it to inflict damage a move later.
Dg338: White to move
Dg338: Here the kernel is on the h-file; if the
bishop moves, White’s queen gives check and
Black’s king has to move. What to do with
the bishop? It travels on the dark squares, and
the only Black piece on a dark square is the
queen, which the bishop can’t reach in two
moves. But wait: think more carefully about
the first part of the attack—the part against
the king. Where would the king go? Its only
escape would be to g7. If White could attack
that square with his bishop, the king would
have no place to go. So Bf8 is mate: a case of
discovered checkmate. The important lesson
is that when you think of where you might
move the unmasking piece, don’t overlook
pressure it can exert against squares, and especially against squares next to the enemy
king.
3.1.10. Removing Impediments to Discovered Checks.
We have seen how to deal with obstacles that
may stand in the way of a normal discovered
attack—how to create good targets for each
piece, and how to open blocked lines. The
same methods come in handy when building
discovered checks, so there is no need to rehearse them here in detail; but since their use
here sometimes looks a little different, a few
examples may be useful. First, discovered
checks often have to be created by making a
threat or sacrifice that brings the king within
range of the stationary piece. And since an
unmasking bishop can go after enemy pieces
that sit on the same color squares where it
travels, you sometimes have to force a target
onto one of those squares.
Dg339: Black to move
Dg339: In the frame, Black has the kernel of a
discovered attack on the g-file: the rook be-
hind the bishop. If Black unmasks the rook it
will attack the pawn at g2, adjacent to White's
king; if the king were moved over a square,
Black would have a far more potent possibility: a discovered check. How to move the
king?
Look for other pieces Black can use to check
it, capture pieces next to it, or both. There is
one option: Qxg2+. White’s only legal reply
is KxQ. Now that the king has been lured
onto the g-file, all that remains is to find a
good target for the unmasking piece—the
bishop on g7. It travels on dark squares.
White’s queen is on a dark square. So Bxe5+
takes a bishop, puts White’s king in check,
and wins back White’s queen after Black’s
next move.
By the way, if you have studied the chapter
on bishop forks, another idea for Black should
cry out for attention here as well: BxB+, forking White's king and queen. What makes it
especially interesting is that if White takes the
bishop, Black then appears to have mate:
Qxg2#, with cover provided by the rook on
g8. Indeed, Black seems ready to mate soon
no matter how White replies to BxB. But not
quite; for the surprising actual result of
Black's bishop fork is that it permits White to
mate! The point to notice is that when White
replies to the fork with QxB on e5, he checks
Black's king and seizes the initiative. Black
has to play Rg7 to block the check. Then
White plays Rg3; this not only blocks Black's
mate threat against g2, but allows White to
mate a moment later on g7 with QxR. There
is nothing Black can do to stop it; his queen is
too far out of position to help. The moral: you
must be especially careful to observe whether
any of your opponent's replies to your ideas
will put you in check. It can ruin everything.
Dg340: White has the kernel of a discovery
on the c-file, but it's not yet in working order.
The rook on c1, if unmasked, has nothing but
a protected rook as a target, and the unmasking bishop likewise is unable to threaten anything more valuable than itself.
Dg340: White to move
Dg341: White to move
But with the kernel in place, think hard about
what it would take to make it succeed. Try
saying “if only…” If only Black’s king were
on the c file, White would have a discovered
check and could take Black’s loose bishop
with two moves. So now think about ways to
move the king by attacking it with other
pieces. The only useful piece for the purpose
is White’s rook on d2. Can it give check?
Yes, with Rd7+. Examine the move. Critically, it’s a fork of Black’s king and his loose
bishop; if Black moves his king, he loses a
piece. His only way to stop the check and also
protect the bishop is by moving his rook onto
the seventh rank: Rc7. Now what checks
would White have, and with what results?
RxR+, leading to KxR; and then—aha!—the
king has been drawn onto the c-file. White
unmasks a discovered check with Bf8+, winning the bishop on g8 after Black's king
moves.
Dg341: Here is a small study in how the
threat of a discovery can influence other matters on the board. White has the makings of a
discovered attack on the e-file. What could
the rook on e1 attack if the bishop in front of
it were moved? Just the pawn on e6. But notice that behind that pawn lies Black’s king.
It’s another “if only” point: if only the pawn
on e6 were gone, White would have a discovered check with Ba6+, winning the queen
after Black moves his king. This means that
the Black pawn on e6 in effect is pinned in
place. White is free to play d4-d5 if he
wishes; if Black captures with e6xd5, White
replies with his discovered check. So if he is
alert Black will instead reply with a move like
Bd6 (preparing to castle) and allow White to
play d5xe6 next move, planning to respond
with f7xe6—but now Black’s position for
castling is not quite so strong. Indeed, notice
that Black’s position overall is rather poor. He
is behind in development (too many pieces
still on their original squares), and he has
weak light-colored squares on his queenside
(“weak” in the sense that White can put
pieces on them and Black can’t chase them
away with pawns)—made worse by the fact
that Black’s light-colored bishop, which he
might have used to protect those squares, is
off the board, while White’s still is available.
You could have seen all this as well by noticing that the bishop on g7 is loose and thus an
important target. You look for forks that
would attack it and find one in Rd7+; you
imagine the reply Rc7 from Black; this invites
an exchange of rooks on c7; put this together
with the kernel of the discovery on the c-file
and you are led back to the g7 bishop as a
target—but this time as the target of a discovery rather than a fork.
Please excuse the absence of the White king
from g1. He's having a break.
In any event, the general point of the study is
just to see how the possibility of a discovered
check in the background can influence other
features of the game. The threat of it can paralyze those pieces that prevent its execution
and so permit advances that would not otherwise be feasible. Here it ultimately causes
Black to end up with an isolated pawn and
bad castling position.
3.1.11. The Bishop and Rook Mate.
Since we have been considering positions
where a bishop unmasks check by a rook or
queen, let's look at one especially important
application in detail. The unmasking bishop
need not always go hunting for an enemy
piece to capture; it also may be able to move
to a diagonal where it can contribute to
checkmate. The key mating pattern we will
examine is this: a rook attacks the enemy king
along its file, with a bishop (a) providing protection for the rook, and often (b) helping to
seal off the king’s flight squares. Here we will
look at some examples of how the pattern
looks in practice.
Dg343: White to move
Dg343: Where does White have the kernel of
a discovered attack? On the g-file. You look
for a target for the rook once it is unmasked
and find none. If only the king could be
drawn onto the g-file, you think; and so you
look for ways to make it happen. What checks
are available? Qg8+. Black’s only legal reply
is KxQ, moving his king onto the sensitive
line. Now if White moves his bishop he gives
check with his rook, so the question is what
move to make with the bishop. It had better
be good, since White sacrificed his queen to
get here. A combined attack against the king
is indicated; Be6++ checks the king with both
bishop and rook. Black’s only move is to retreat the king to h8. Now comes mate: Rg8#,
with the rook attacking the king and its only
flight square, and getting cover from the
bishop.
Dg342: Black to move
Dg342: In the position Black has the makings
of a discovered check on the f-file. He can go
looking for White pieces to take with his
bishop, but the better plan is to move the
bishop to a diagonal where it, too, can be
brought to bear against White’s king. Hence
Bd3++—a case of double check where two of
Black’s pieces attack White's king at the same
time. In response to a double check the only
legal reply is to move the king. Here it must
go to e1. Now comes the classic mate: Rf1#.
See how the rook makes the first rank and the
f-file impossible places for the king to be,
while the bishop on d3 (a) protects the rook
and (b) closes off the king’s other possible
flight square, e2.
Dg344: Black to move
Dg344: Black has the kernel of a discovered
attack on the f-file. The potential target for his
rook is White’s rook on f1—which is protected, however, by the enemy king. Black’s
queen is trained on the rook already, so the
solution is an exchange: Black plays QxR+,
requiring the reply KxQ. Now the king is on
the f-file, so when Black moves his bishop he
has a discovered check. But instead of looking for White pieces to attack with the bishop,
think first about ways to give check with it—
i.e., double check—and go for mate. Bd3++
forces the king to move. This time it can go
two ways: back to g1 or on to e1. Either way
Black executes the now-familiar mate pattern
with Rf1#.
Dg346: Black to move
Dg345: White to move
Dg345: White has the kernel of a discovered
attack on the d-file, where the bishop masks
the rook. What prevents this from being an
effective discovered attack, or indeed a discovered check? First, White’s own queen
blocks the rook’s path up the file; second,
there is not yet a Black target on the file. The
solution to these problems becomes clear
enough when they are viewed together: use
the queen to bring the king into range. Thus
Qd8+ forces KxQ. Since White will have sacrificed his queen, he will be interested in
mate; can he get it? Bg5++ gives check with
both bishop and rook; Black must move his
king. He can take it two places: back to e8 or
to c7. If he plays Ke8, White follows with
Rd8#, using our current pattern. If Black
plays Kc7, look for White’s next check: he
plays Bd8#, using something like the reverse
of the current pattern. The bishop attacks the
king and cuts off the flight squares on its diagonal; the rook protects the bishop and cuts
off the Black king’s remaining flight squares.
(White could have made a different second
move, of course: Ba5+, giving the double
check from the other side of the board. But it
doesn't work; Black's king soon can escape to
e6.)
Dg346: Black’s queen is about to get taken by
the rook on d4, so it would be natural to think
about moving it to safety; but Black can do
better. Think about offense and notice the
kernel of a discovery on the e-file. What target would the rook have if it were unmasked?
It would be aimed at White’s king, and the
check could be made a double with Bb4—if
only the White pawn on e3 weren’t in the
way. With the obstacle identified, be methodical in getting rid of it. Try capturing
something the pawn protects. It guards the
rook on d4, which Black can take with QxR.
Now if White replies e3xQ the e-file has been
opened for the double check Bb4++. White
then has to move his king to d1, permitting
Black to execute the standard mate: Re1#,
cutting off the king’s flight squares on the
first rank and on the e-file while the bishop
protects the rook and cuts off d2.
Dg347: White to move
Dg347: Now let us tilt the pattern we are
studying on its side. White has the makings of
a discovered attack on the h-file, where his
bishop masks his queen. Naturally you experiment with moves that take the bishop out
of the way and allow the queen to give check.
But before getting too far into the bishop's
possibilities, ask what the king would do once
checked and whether the bishop might aid in
the creation of a mating net. The king is stuck
on the side of the board and so could only be
moved to g7. The bishop might cut off this
possibility with Bf8+. So then what would
Black do? Since moving the king would be
impossible, he would interpose his bishop on
h5. This way if White plays QxB he loses the
queen to g6xQ.
Don’t give up, though; always ask what
checks would have become possible at the
end of the sequence you are considering. Here
the answer lies in White’s d6 rook that also is
trained on the same sector. Imagine 1. Bf8+,
Bh5; 2. QxB+, g6xQ, and now notice that
with the g6 pawn moved out of the way,
White has a fresh check to offer: Rh6—mate!
The rook and bishop operate the same way
here as they have in the previous examples;
the only difference is that they do it on the
side of the board rather than along the top or
bottom.
The keys to the position are, first, to be aggressive in imagining 2. QxB, even though on
its face it looks suicidal; and, second, to consider how your rook can get in on the act.
Once your mind becomes focused on a pattern, such as the business here with queen and
bishop, it it easy to forget how your other
pieces might be able to rush in and assist once
the board has changed a little. Many a sequence is salvaged and then made crushing by
adding new, unexpected firepower after the
pieces which first start the combination are
spent.
while the mobile, unmasking piece remains
free to make two attacking moves.
Dg348: White to move
Dg348: In this first position, White’s bishop
and rook are in the natural position for a discovery. The rook is aimed at Black’s queen, a
threat so powerful that unmasking the rook
works much like a discovered check: White
will get to make two unfettered moves with
his bishop while Black saves his queen. White
doesn't quite have the same flexibility in attacking the queen that he would have with a
discovered check, because unlike a king the
queen sometimes can move out of harm’s way
and guard against whatever threat the mobile
piece has made. But that doesn't spoil White’s
possibilities here. He looks for a two-move
attack he can launch with his light-squared
bishop, and sees that Black’s rook is loose
and lies on a light-colored square. Ba6 thus
attacks the rook on move one and wins it on
move two (unless Black plays QxRe1, preferring to lose a queen for a rook rather than losing a rook outright).
3.1.12. Other Large Threats By the Stationary Piece.
The logic of the discovered check sometimes
can arise in positions where the unmasked
piece doesn't give check but makes a different
threat—perhaps a threat of mate, or a threat
against the queen—that nevertheless is so
powerful that it must be addressed; mean-
Dg349: Black to move
Dg349: One way to start a tactical assessment
is by just considering what each of your
pieces can do. This includes an automatic
glance not only at the diagonals where your
bishops sit but also at their ranks and files to
see if they contain allied pieces that might be
able to deliver discovered attacks. Here
Black's bishop on d7 hides the rook on d8
with nothing otherwise blocking the rook’s
path to White’s queen. The setup is perfect for
a discovery—not quite a discovered check,
but an attack based on the same model where
the unmasked piece creates a distraction that
the enemy must address while the unmasking
piece is given two moves to inflict harm. So
Black looks for violent moves to make with
his bishop and thus finds BxN. Since White
will be confronted with a threat to his queen,
he won’t be able to recapture with e4xB;
Black therefore will be able to withdraw his
bishop to safety on his next move and will
have gained a piece.
from White’s stationary piece, so White’s
bishop—the unmasking piece—will get a free
second move. White thus plays Bd5, attacking
the queen.
Indeed, follow the possible resulting moves
and you find that White need not be satisfied
with the queen; mate soon follows no matter
what Black does. If Black plays QxBd5, for
example, he might seem to have created a
defense against mate: if White plays RxR+,
Black can play Qg8, blocking the check—yet
then White mates with RxQ. If Black instead
tries to extinguish the mate threat by replying
to Bd5 with RxRf2, White can skip BxQ and
just go straight for Black’s king with Qg8#;
the queen gets cover from the bishop on d5.
Black's "best" reply to Bd5 (it hardly matters)
is Rd6-f6; all this does is throw a blocker onto
the f-file. White's rook plows through it and
Black soon runs out of stalling maneuvers.
Dg351: Black to move
Dg350: White to move
Dg350: Here’s a variation on the current idea.
Where does White have the kernel of a discovered attack? On the f-file. (The f7 bishop
and f2 rook are separated more than is usual,
but it’s no less important to see their relationship.) Having found the kernel, ask what the
rook could do if the bishop were out of the
way. It could attack Black’s rook on f8.
That’s something, but on inspection of
Black’s king there is more: the king has no
flight squares and not many guards; so if
White could play RxR it would be mate. This
means that if the bishop vacates f7 it creates a
discovered mating threat in RxR that functions like a discovered check: Black will have
no choice but to fend off the threat to his king
Dg351: The crucial square to focus on this
time is g2. Black has a knight already attacking it, and his queen is aimed the same way; if
he could get his queen onto g2, it would be
mate. The queen’s path to g2 is blocked by
his bishop. He could try attacking g2 by first
moving his queen to c6, but this gives White a
move he can use to defend g2 with Qg3. So
focus instead on the g-file, where Black has
the kernel of a discovery. If the bishop were
gone the queen would threaten to mate, so
Black looks for mischief he might make with
his bishop—or, better, some way it might help
with the queen's landing on g2. He finds no
checks or captures for the bishop but identifies a move that nevertheless is effective:
Be3, which attacks the bishop on f2 and pins
it to White’s king; it also cuts off the path of
the White queen along the third rank toward
any possible defense of the g2 square. White
is doomed:
(a) If he captures Black’s bishop with his
own, his queen remains blocked; Black mates
with Qxg2.
(b) If White instead uses his queen to take
Black’s bishop, he likewise is mated immediately by Qxg2.
(c) If White advances his g-pawn to g3, Black
plays Qxg3+ and mates a move later.
(d) If White advances his g-pawn to g4, he
effectively blocks the descent of Black’s
queen down the g-file, but Black plays Qc6
and again mates soon on g2; for the third rank
still is impassable to White’s queen.
Dg352: White to move
Dg352: This is a rich, difficult position that
will reward some study time. Presumably you
see that White has the kernel of a discovery
on the f-file. You also see a natural way to
execute it: 1. Bc7, attacking Black’s queen
and also threatening 2. Qxf7+. But you wonder how formidable the latter threat really is.
Suppose Black replies to 1. Bc7 with 1. ...
QxB, allowing White to carry out Qxf7. Now
Black’s king is forced to h8—and then what?
Your queen can do no more by itself from f7.
The key move to see is 3. Rh4—a fresh mate
threat (Rxh7#) against Black’s king on its
new square. Black has a move he can spend
responding to it but there is nothing he can do
to avoid trouble. He can’t get any of his
pieces to h7 to defend the square. The most he
can do is advance his h-pawn. The first possibility, 3. ...h7-h6, doesn’t help: it results in 4.
Rxh6+, BxR; 5. Qh7#. Black's second option,
3. ...h7-h5, is a little better as it avoids mate.
Play goes 4. Rxh5+, g6xR; 5. Qxh5+ (always
looking for the next check), Kg8; 6. Qh7+,
Kf8; 7. Ne6+ (forking Black’s king and
queen). The net: White gives up a bishop and
a rook to gain a queen, three pawns, and a
better game (his offensive continues; there are
various ways he might win still more material).
Assuming you follow all this (it's worth a
patient look), what does it prove? Just that if
Black replies to 1. Bc7 by playing QxB, he
gets hurt; so Bc7 does indeed give White a
working discovered attack. But what will
Black do about it? Obviously he doesn’t want
to simply forfeit his queen; does he have anything better? Ideally he would like a move
that makes a good counter-threat against
White while also defending against mate.
Black almost has such an option in 1. ...Ne5,
attacking White’s queen and guarding f7. Of
course it loses the piece to BxN, but it’s still
Black’s best reply.
This position contains a couple of natural
“stuck points”—places in the analysis where
it’s easy to hit a wall. The first comes after
you see 1. Bc7, QxB; 2. Qxf7+, Kh8—and
now it needs to occur to you to bring the rook
over to h4, which is tricky to see for several
reasons:
(a) Rh4 brings a piece into the action that had
not initially appeared to be part of the plan.
It’s natural when you begin playing with a
tactical idea to focus on the principal pieces
involved—here, White’s queen, bishop and
knight. But as we recently had occasion to
note, many a sequence turns out to depend
precisely on the clever addition of an unexpected piece or pawn to the attack. This is a
key reason why developing your pieces (i.e.,
getting them off of their original squares) is
important before launching an offensive.
They all may have the potential to perform
supporting roles. The repeating moral: think
about all of your pieces and how they can
help when planning a tactical sequence.
(b) Rh4 requires you to remember that the
bishop now on f4 would be gone after the first
move and that this would open a line for your
rook to use to reach the h-file. This is a standard sort of cognitive challenge at the chessboard. The only cure is to be careful about it
when you practice visualizing these sequences: every time you make a move, think
not only of the piece on its new square but
also of its absence from the old one.
(c) Rh4 is not a forcing move in the strong
sense associated with a check or capture, so it
might not spring to mind as quickly as those
other possibilities would. But it still requires a
look because it creates a mate threat: it aims a
piece at a square next to the enemy king that
you already have under attack. It therefore
forces Black’s reply; it make him advance his
h-pawn, which ends up having other consequences as well. Moves of your heavy pieces
(your queen or rooks) to the h-file against the
castled enemy king are common sources of
good, forcing threats.
A second natural stuck point comes after 3.
Rh4, h7-h5; 4. Rxh5, g6xR; 5. Qxh5, Kg8; 6.
Qh7+, Kf8. At this point you need to see 7.
Ne6+—the knight fork. You might overlook it
by thinking in a rut. You have been trying to
chase down Black’s king with your queen;
now you have run out of ways to do it. The
earlier point repeats: when your idea hits a
wall, remember to ask afresh how your other
pieces might help, and whether some new
tactical idea might make an unexpected appearance. This is especially important when
you have a knight in the vicinity and the enemy king is moving; the potential for a knight
fork may pop up at any time during a sequence. (And of course you have to remember
as well that at this late stage of the sequences
Black's queen still sits on c7, where it went on
Black's first move.)
3.1.13. Horizontal Discovered Checks.
Naturally a discovered check can occur horizontally along a rank as well as vertically
along a file. Here are a few examples of what
the horizontal patterns look like.
Dg353: White to move
Dg353: In the diagram White has the makings
of a horizontal discovered check on the eighth
rank. The Black king is in place; the only
question is what the bishop should do to take
advantage of the check that will occur once it
moves out of the rook’s way. It could take
Black’s knight, of course, with Be7+, but it
would be a mistake to settle for so little. Consider first the king’s response to the discovered check; ask whether the unmasking piece
might add to a mating net. In this case the
king would be forced to move to g7. Can
White’s bishop attack that square when it unmasks the rook? Yes: 1. Bf6# is mate.
Dg354: White to move
Dg354: Where does White have the kernel of
a discovered attack? Not on any file, of
course, but along the sixth rank. It isn't easy
to see because at present the rook has no target once unmasked; but White would have a
discovered check if Black’s king could be
drawn onto h6. Experiment with any checks
White can give using other pieces—or pawns.
Here h5-h6+ checks the king; it also puts a
pawn on the square where we want Black’s
king to go, inviting a capture there.
Black has two options: take the pawn or move
the king to the back rank. If he goes the latter
route, consider first what checks would be
possible and you find Re8—which is checkmate. (See how the pawn on h6 and the
bishop on g6 together seal off all the king's
flight squares on the seventh rank.) So instead
Black will have to play 1. ...Kxh6. But now
he has put his king on the same line with
White’s bishop and rook and has made it prey
to a discovered check. White merely needs to
find something good for his bishop to spend
two moves doing, and he finds it in Be8+.
After Black moves his king out of check,
White plays BxR, winning the rook.
Realistically, the most likely way you would
see the tactical idea here is to start by examining the h5-h6 check as a matter of course;
then you see that after Kxh6 you have a discovered check arranged—and that if the king
instead retreats you have mate.
Dg355: White to move
Dg355: Where does White have the makings
of a discovered attack? On the third rank,
where the bishop masks the queen. Well, in
practice you probably would not think quite
like that, since the queen so plainly has no
target on its rank if the bishop moves out of
the way. The real key to seeing what can be
done here is to examine Black’s king and its
vulnerabilities. It is stuck in the corner;
White’s bishop on b3 covers g8. And the file
leading to the king is open. The king’s lack of
pawn cover and constricted movement cry out
for an attack along the h-file; if White could
get one of his heavy pieces (the queen or a
rook) onto h3, it would be mate. Therein lies
the winning idea, for White’s queen already is
aimed at h3. If the bishop moves out of the
way, White’s threat against that square thus is
a mate threat, and requires a response from
Black just as a check would. So now all
White needs is a dark-squared target that his
bishop can reach in two moves. The queen is
the target of choice; Bxb6 wins it after Black
plays Nf8 (preparing to fend off the mating
threat with his knight).
Dg356: White to move
Dg356: The kernel of the discovery here
should be obvious enough: White is poised to
give check on the seventh rank by moving the
bishop out of the rook’s way. He needs a
good target for the bishop. It’s on a light
square; what Black pieces are on light
squares? None. But that is no reason to give
up. White’s task is clear: get a Black piece
onto a light square—probably by forcing one
of them to move there with a threat. Pawns
are best for this purpose, since in the face of a
pawn threat a piece usually must move; the
threat can't be dealt with by just adding protection to the piece. A threat against a knight
is especially useful here because every time a
knight moves it switches to a different colored
square. So b3-b4 forces the knight to move,
and wherever it goes it gets taken—either
right away by White’s bishop or rook, or (if
the knight moves to c6) by the discovered
check Bd5+. After Black moves his king,
BxN then takes the piece, which is defended
by Black’s rook but also attacked a second
time by White’s rook.
3.1.14. Two-steppers: Building the Kernel.
The first step in our usual studies of the discovered attack has been to find the kernel of it
and build from there. But what if the kernel
doesn't yet exist? Then a bit more imagination
is required: you need to experiment with
moves — here, moves by bishops and the
pieces they can mask—that create kernels;
you learn to notice when a move or exchange
you might make will bring the kernel of a
discovery into existence. Here are some illustrations.
Dg357: White to move
Dg357: In the study White sees that he has a
rook on the open e-file. He has a bishop that
can reach the same file with Be7, masking the
rook. Look at the position of the bishop and
rook here; see how they thus are one move
away from being in the classic formation for a
discovery. The question is whether the move
that creates the kernel also forces a target into
place. Here the bishop’s move to e7 would
threaten Black’s rook on f8. Black’s reply
would be forced and thus easy to foresee: the
rook would have to move to e8. This little
sequence would create a working discovered
attack: a masked piece, a masking piece, and
a target all along the e-file. Now the bishop
just needs a good place to go next. Bb4
threatens Black’s queen; if the queen defends
itself in any way, White plays RxR#. So the
queen must be lost. Notice how easy this position would be if it started with the kernel intact (i.e., with 1. Be7, Re8 already played).
The challenge is just to think of White moving his bishop in front of his rook and to carefully consider the result.
Dg358: Black to move
Dg358: Black faces the threat of mate with
RxR, so if he’s going to take the offensive
elsewhere he will need to work with checks
that force White to play defense. The checks
he can give with his queen—Qxh2, Qf1, or
moves to the g-file—don’t quite work; but
how about 1. …Bxh2+? White’s only legal
reply is 2. Kh1, retreating into the corner. But
now the full kernel of a discovered check has
been completed: Black’s queen is behind his
bishop and aimed at White’s king. This almost enables a mating sequence with 2.
…Bg3+ 3. Kg1, Qh2+ 3. Kf1, Qxf2#. That
last move won’t succeed here because of
White’s knight on d1, however, so Black
needs something else for his bishop to do as it
clears the h-file and discovers check. It can’t
attack anything; it’s on a dark square and all
of White’s pieces are all on light squares. But
consider whether it usefully might block any
lines. With 2. …Be5, Black severs the protection White’s queen had provided to the rook
on e8. Again White must move his king to g1;
and now Black plays RxR.
Dg359: White to move
Dg359: Start by examining every check.
White has two: Rh8, which loses the rook
without a good follow-up, and Bh7, which
checks the king and (since the bishop is protected against capture) requires the king to
retreat to h8. And now—aha!—we have the
kernel of a discovered check: White’s bishop
masks the path of his rook toward Black’s
king. So where should he move the bishop? It
has no good Black targets on light squares,
but the more important possibility to consider
is that the bishop might help finish Black's
king. The best piece to involve as a help toward that end is his queen. White would mate
if it could be placed on h7; and what keeps it
from being placed there is the presence of
White’s own bishop on the needed diagonal.
So we remove the bishop from the line with 2.
Bg8+. Black has to move his king out of
check with KxB or Bh6; either way, White
has Qh7#. (The queen takes protection either
from the rook on h1 or the bishop on g8, depending where Black's king moved.)
Dg360: Black to move
Dg360: Now a defensive use of our current
idea, and in a horizontal setting. Black is
ahead a piece. He has to address the threat
against his knight now made by White’s king.
How? With offense: Black has a bishop on
the eighth rank and can move his queen behind it with Qd8. That move creates the kernel of a discovered attack against White's
queen. To make the threat really interesting
the bishop would need somewhere good to
go. Can it reach White’s king? Not quite; it
can move to a6, though, at which point it is
aimed at—the threatened knight. Now the
defensive idea comes together: if Black plays
Qd8 and White then plays KxN, as he now
threatens to do, Black would be able to win
the queen with Ba6+. Odd as it may seem, by
moving his queen to d8 Black thus defends
his knight on e2: he creates a discovered attack that will be unleashed if his knight is
taken.
Dg361: Black to move
Dg361: Again White’s king can take Black’s
knight on e2. Black has a bigger problem, too,
for White threatens to mate by playing Qf7+,
forcing Black’s king to h8 and then mating on
f8 (his queen goes there and gets taken by
Black’s rook; then White has RxR#). Yet
Black can address both problems with the ingenious Qe8. See what this does: now Black’s
queen is on the e-file, ready to defend the
knight once his bishop on e5 has moved out
of the way. In other words, the kernel of a
discovery has been created expressly to protect a fellow piece at the other end of it. Indeed, this does better than protect the knight
and defend f7 against mate. It means that if
White plays KxN, Black then has a discovered check with Bb8+, attacking White’s queen
as well as his king.
We aren’t finished; don't forget to consider
what White would do about the check you are
imagining when Black moves his bishop out
of the way. White could interpose his rook
with Re3, not only blocking the check but
attacking Black’s queen. So then what? Black
looks for another check that would then be
possible; so long as he keeps White busy with
checks, the capture BxQ will still be waiting
for him afterwards. Here Black’s next check
is Qb5+. White again can interpose the rook,
but this time it only blocks the check; it can
pose no threat against a queen attacking along
a diagonal. Now it's safe for Black’s bishop to
take White’s queen.
3.2. Rook Discoveries.
3.2.1. Introduction; Simple Cases.
Dg362: White to move
Dg362: You might start this one by observing
that White's f5 bishop can give check with Bx
h7. By itself this doesn't achieve anything, but
it's something to know as you think through
your options. Okay, now look at your other
forcing moves — your possible captures —
and what they do. There is 1. NxN, inviting
Black to retake with QxN. The interesting
thing about this exchange is that it puts
Black's queen on a line with the White bishop,
which we know can give check.
Maybe now you begin thinking about slipping
White's queen onto h5 to create the structure
of a discovered attack on the fifth rank; you
wonder how you might do it in a violent manner that forces Black's reply and keeps the
discovery intact. Or maybe you just keep
looking for other captures you can make. Either way you come to inspect 2. Bxg7. Black
has to reply BxB or else lose the rook on f8.
But after Black plays BxB the way is clear for
White to play 3. Qh5, threatening mate with
Qxh7. The mate threat is easy for Black to
defang, of course, with h7-h6, but it serves its
purpose: White gets his queen onto line with
his bishop and with Black's queen, and Black
has had no time to fend off the discovered
attack that now has been set up on the fifth
rank. White pulls the trigger with 4. Bh7+,
requiring Black to play KxB and unmasking
5. QxQ. White wins Black’s queen and pawn
in return for his two bishops.
We turn now to a different pattern: the rook
that blocks and then unmasks an attack along
a diagonal by a bishop or queen. In a way the
pattern is the reverse of a bishop discovery;
this time the unmasker moves vertically or
horizontally while the attacker runs on a diagonal. Since the mechanics involved are familiar, we won't spend quite as much time on
the rook as we did on the bishop or as we will
on the knight. Still, there are some differences
between the patterns that are worth a few
moments of special attention and visual absorbtion.
First, an unmasking rook usually has a harder
time giving check than an unmasking bishop
does. The bishop can act as a dive bomber,
coming in on a diagonal to attack the king
from above or below; the rook has to deliver
check by moving straight down onto the
king’s rank, or (less often) over onto the
king’s file. Either of these moves can unmask
an attack, as we shall see, but they are less
common than the bishop’s strike against, say,
h7. The significance of this is that when the
rook discovers an attack, the distraction it
creates more often is not a check but instead
is some sort of mating threat, typically against
the back rank. And discovered checks—i.e.,
moves where the piece behind the rook gives
the check, rather than the rook itself—also
make up a relatively large share of rook discoveries. Finally, discoveries by the rook also
look different than discoveries by the bishop.
The rook kernel isn’t as easy for the untrained
eye to see as the bishop kernel; the eye is accustomed to looking up and down the files but
not so accustomed to scanning the diagonals
in the same way. The positions in this chapter
are meant to build that visual habit.
Dg363: Let’s begin with positions that are
comparable to the first studies in the chapter
on bishop discoveries. There, a bishop masked a queen or rook that was ready to attack
an enemy piece along a file; here, a rook
masks a bishop or queen that is prepared to
attack an enemy piece along a diagonal.
lar to the last one and is offered mostly for the
sake of pattern reinforcement. They differ in
trivial respects: the White pieces comprising
the kernel of the discovery are another square
apart, and this time it’s the queen rather than
the bishop that is unmasked. But the execution is about the same. Black’s queen starts
out as a bad target because it has protection
from the knight on g7. White can eliminate
the guard while unmasking the queen—and
can do it with check: RxN+. After KxR,
White plays QxQ and wins a queen and a
knight for a rook.
Dg363: White to move
There, the bishop unmasked the attacking
piece with a diagonal move that checked the
enemy king; here, the rook unmasks the attacker with a “vertical” move—a move down
a file—that checks the enemy king. In either
case, the unmasked piece has time to make its
capture after the check is fended off.
Where does White have the makings of a discovered attack in this first example to the left?
The answer presents a new pattern: it’s on the
diagonal f1-h3, where the rook masks an attack by the bishop against Black’s queen. The
questions about the idea's execution are familiar: what violent move can the rook make that
will require a time-consuming response from
Black, giving the bishop time to take Black’s
queen? The answer, of course, is a check:
Rxg7+ requires Black to play KxR (or move
his king); and now White plays BxQ.
Dg365: White to move
Dg365: The general idea here is the same as
before: see the queen-behind-rook pattern for
White, this time running in the other direction; notice the Black queen, poised to be
taken by White’s queen if the rook can move
out of the way with check. Here the rook’s
check probably is of its most common type:
the move to the back rank, in this case with
Re8+. The check easily is defused with RxR,
but then White wins the queen with QxQ.
Dg364: White to move
Dg366: Black to move
Dg364: Where does White have the makings
of a discovered attack? This position is simi-
Dg366: Where does Black have the makings
of a discovered attack? There is nothing on
the files or ranks, but along the g1-a7 diagonal Black has a bishop masked by a rook.
Does the bishop have a suitable target if the
rook moves? Yes, in White’s unprotected
knight. As discussed in more detail in our
work on forks, an unprotected or “loose”
piece always calls for a look at whether it can
be taken with a tactical maneuver. Here the
question is whether Black can vacate his rook
from c5 in a manner that is time-consuming
enough to allow him to take the knight a
move later—and that doesn’t lose the rook.
(Since the payoff of the discovery is just going to be a knight, Black can’t afford to sacrifice his rook the way he did in the previous
positions.) So Black looks for safe rook
checks and finds Rc1+, where the rook is
covered by Black’s bishop at e3. The move
forces the king to move to a2 and then allows
Black to play BxN safely.
what large threat can White create with the
rook?
3.2.2. Threatening Mate.
Now notice that if it were Black’s turn to
move he would have Qa1+. White would be
forced to reply KxQ—after which Black has
the knight fork NxB, winning a piece. This
should worry you a little for the reason
sketched a couple of paragraphs above. The
first move in White’s planned sequence
(Rxf6) is a capture and mate threat, but not a
check; so you have to consider whether he
can give checks of his own that will derail
your plans. In this case Black could respond
to Rxf6 with two consecutive checks, as just
discussed: Qa1+, and then NxB+, forcing
White to move his king. So are White's plans
foiled? No; for then Black is out of checks
that hold the initiative: the next move he
wants to play is NxQ, but he can’t afford it
because Black mates with RxR. White thus
holds onto the queen.
In the positions just seen, the attacking player
used his rook to give check. The opponent’s
need to defend against the check gave the
piece that had been uncovered by the rook
time to win material on the next move. Sometimes the rook can achieve much the same
effect by threatening mate, as this puts the
enemy under pressure similar to that created
by a check. A rook most commonly can
threaten mate by offering to drop onto the
back rank when the enemy king is trapped
there. This theme is worth our independent
attention for two reasons. First, seeing a mate
threat often is harder than seeing a check; it
takes some practice. Second, when you work
with mate threats you have to be especially
careful to consider what trouble your opponent can make in reply. Since by assumption
you haven't put him in check, you may have
left him with latitude to respond with checks
of his own that seize the initiative.
Dg367: In the current position White has the
kernel of a discovered attack along the g1-a7
diagonal, where his rook masks his queen—
which otherwise would be able to take
Black’s queen. Now think about execution:
Dg367: White to move
Rxf6 is its only capture, but the move is more
than that: it aims the rook at f8, where it
would mate the trapped Black king with
RxR#. So in reply to 1. Rxf6 Black has to
capture White’s rook, which of course creates
time for White to play QxQ on his next move.
Dg368: A similar idea. First find where White
has the makings of a discovered attack. The
kernel lies on the long a1-h8 diagonal, where
White’s rook masks his queen in familiar
fashion. Look for a target for the queen once
it’s unmasked and see that Black’s queen is in
the line of fire—and that it's loose.
Dg368: White to move
Dg369: Black to move
The challenge now is straightforward: vacate
the rook from d4 in a way that compels a response from Black. The rook has no checks,
so examine the Black king’s position for vulnerabilities. It is trapped on the back rank;
although it isn’t entirely sealed in by its
pawns, White’s bishop closes off the flight
square on g7. The same idea we saw in the
previous position thus works here. An attack
by White’s rook against Black’s rook on e8
would be a mating threat, because if White
can play RxR the game ends. White makes
the threat with Re4. Black has to eliminate
White’s rook to stay in the game. He has two
ways to do it. The first is BxR, to which
White replies QxQ and mates soon. Black
also has the option of replying to Re4 with
RxR. How should White reply?
On the long a8-h1 diagonal. As usual the rook
masks the queen, and if it were moved Black
could play QxQ. The important question involves what to do with the rook. Again it has
no checks, so consider the White king and its
vulnerabilities. Here as in the previous position it is stuck on the back rank, as Black’s
bishop on h3 cuts off its escape. And once
more the king has a single guard: the rook on
e1. If Black threatens that rook with his own,
he threatens mate. So he has two possibilities,
either of which works: 1. …Rd1 or 1. …Re5.
This time the answer for White isn't quite
QxQ, since Black then uses his rook to mate
on e1. White instead needs to work with
checks to prevent that possibility. By moving
his rook off the back rank, Black has made
this easy: White plays Qc8+, which requires
Black to interpose his queen on d8. White
takes it (QxQ+); then we go through the same
process with Black's rook; then it's mate.
There is a little more to say, because you always must ask whether your opponent has a
way to both move the targeted piece out of
danger and spoil the mating threat. White's
queen can't move to the east because Black
then threatens to mate with Qg2. But in response to either of those rook moves we have
sketched, White can play 2. Qxh3, avoiding
QxQ and preparing to interpose the queen on
f1 if Black plays RxR. But then he still loses
the queen—and also both rooks. It goes 2.
…RxR+, 3. Qf1, RxQ+, 4. KxR, QxRh1+.
Black has a queen left and White has nothing.
Black's best reply to 1. Re4 is probably 1.
...Qe5, which avoids the mate just shown but
loses his queen and then his bishop.
Dg369: Another variation on the same idea,
this time from Black’s side. Where does
Black have the makings of a discovered attack?
Dg370: Black to move
Dg370: Observe the offensive tension on the
board. Black would like to use his queen to
take White’s rook on f5, but then he would
lose his own rook to White’s queen. How to
break the jam? By use of the queen-rookqueen alignment on the e1-a5 diagonal—the
three-piece kernel of a discovery. White’s
queen is ready to be taken if the rook can vacate c3 with sufficient violence. The rook has
no way to give check, but study White’s king:
it’s trapped on the back rank. If Black could
land a rook there he might have a mate
threat—except for the protection furnished by
White’s rook on b1; if Black could take that
rook with his own, he would indeed threaten
mate. So the threat by Black of RxR is almost
as good as a check, and Black can achieve
this with 1. ...Rb3.
What next? White is confronted with multiple
threats, so he might naturally look for a way
to defuse them both—a square where his
queen would be safe and would defend
against RxR#. One possibility is 2. Qc1. This
takes care of those two problems, but not a
third one: Black now can play QxR with no
worries, because White’s queen no longer is
in position to retaliate by taking the rook on
c3. (But before playing QxR Black has to
exchange rooks on b1; otherwise White meets
Black’s QxR with c2xR.) White is left with a
queen against Black’s bishop and queen. A
better reply idea for White would be 2.
a2xRb3. Black then plays QxQ next move, so
this time White has lost a queen for a rook;
but at least he ends up with two rooks against
Black’s queen and bishop.
Dg371: Black to move
Dg371: First note the kernel of a discovered
attack spread along the long h1-a8 diagonal.
If unmasked, the Black bishop could take
White’s queen. Can the rook be vacated from
f3 with check? Yes; Black can play Rf1+, and
White would have to reply RxR (his queen
would then be pinned). Then Black could play
BxQ, to which White replies KxB, and Black
has won a queen for a bishop and a rook.
Don't settle for this, though; think through all
of your options. How else could the rook vacate f3, and with what results? He could
threaten mate with RxN, looking to play
RxR# next move. RxN therefore has about the
same effect as a check but picks up a knight
along the way. Now what would White do?
Stay aware of every piece bearing on the enemy king’s position. Here Black has a second
rook he can involve, this one on the open efile. So if White replies to RxN with RxRd3,
Black plays his other rook to e1—and it’s
mate. White instead needs to create a flight
square for his king, and therefore replies to
RxN with QxB. It avoids checkmate but loses
the queen. The key thing for Black now is not
to play the tempting RxQa8, but to instead use
RxR+. It wins a rook, and since it's a check it
effectively is a free move; White has to spend
his reply saving his king, and so can’t move
his queen out of harm’s way on the eighth
rank. When Black has finished giving checks
and doing whatever damage he can in the
process, White’s queen still will be on a8 for
the taking.
Capturing the rook on d1 first with check,
then taking Black’s queen later, is an example
of using the priority of check—the principle
that a check must be addressed before any
other threat pending on the board. It is a valuable idea that we will revisit often and study
in detail later.
Dg372: By now the queen-and-rook kernel
for Black on the long diagonal no doubt is
obvious. Look for a target for the queen if
unmasked, and see that White’s queen is
loose and ready to be taken on c3.
3.2.3. The Rook Discovers Check.
Dg372: Black to move
Black just needs a threat to make with his
rook on e5. The rook can’t directly threaten
anything at the moment, but the key fact
about the piece is that it is part of a battery of
rooks aimed at White’s back rank. Play
through the first rook capture in your mind’s
eye: 1. ...RxR+, to which White replies 2.
RxR. Now what? The answer is tricky. Are
you inclined to play 2. ...RxR+, checking the
king? Not so fast: White’s queen protects e1,
so White would be able to play 3. QxR, taking
the queen out of danger and dissolving the
check at the same time. Any other ideas?
Consider the surprising 2. ...Re2, which puts
pressure on a square next to White’s king (f2)
that Black already attacks with his queen.
This allows Black to threaten mate with 3.
...Qxf2; White must do something to prevent
it. If he plays 3. QxQ, Black doesn't recapture
right away with g7xQ; rather, he first plays
RxR+, winning a rook and checking White’s
king (the priority of check again). After the
king moves to h2, then Black still has g7xQ—
and only Black’s rook is left on the board. If
White instead plays something other than
QxQ on the second move of the sequence,
Black plays QxQ on his next move.
The hard part of this position is seeing the
value of Re2 for Black. The key point to remember is the sensitivity of squares next to
the king, especially when they already are
attacked by a queen. Adding another attacker
against such squares, as Black does here with
his second rook, can create a crushing threat
even if no check or capture is made with the
move.
Dg373: Black to move
Dg373: We turn to the power of the rook to
discover check. The position on the left illustrates the pattern in simple form. Scan the
diagonals and you see Black’s queen behind
his rook, with White's king at the other end of
the line. The stage is set for a discovered
check; Black just needs a good target for his
rook. Best would be either White’s queen
(because it’s more valuable than the rook) or
any unprotected White piece (because then it
doesn’t matter whether the rook is more valuable). White’s queen can be attacked with
Rc4+; after White protects his king (Kh1 is
best), Black plays RxQ. It would be different
if White could take his queen someplace
where it had protection and blocked the
check, but there is no such square. If White
plays Qe3, for example, Black has QxQ+; this
renews the check and thus gives Black time to
save his rook on his next move.
Dg374: Black to move
Dg374: Here is another way it can go. Black’s
rook masks his bishop, which otherwise
would have an open line to White’s king.
What should Black do with his rook? The
queens are off the board, so Black looks for
pieces he might attack. There are two:
White’s knight and rook. Which is the better
target? The knight, because it is unprotected;
if Black plays Rb2+ and then RxR, he just
ends up exchanging rooks after NxR. The
winning move thus is Ra2+, followed by RxN
after White saves his king.
Dg375: White to move
should go. It will have two moves to inflict
damage, and unlike the bishop it can reach
squares of either color. Naturally White
would like to go after Black’s queen, and he
can. But another critical feature of the rook’s
powers is that it can move both horizontally
or vertically, so there still is a decision to
make: White can attack Black's queen with
Rc5+ or Rd6+. Choose carefully. Your chief
worry in executing a discovered check is that
the targeted piece—here the queen—will be
able to move out of harm’s way in a manner
that also blocks the check. So start by considering Rd6+ and ask whether Black’s queen
would have any such moves. It would; Qc4
would block the check and also lend the
queen protection against QxQ from the pawn
on b5. Now try the other move: Rc5+. This
time the only way Black’s queen could block
the check is by moving to d5 or e6—but on
those squares it gets no protection and so is
lost to e4xQ or QxQ. Rc5+ thus is the winning move for White.
Dg375: White’s rook masks the path of his
bishop toward Black's king, so White’s task is
to find a destructive role for the rook. Again
the queens are off the board, and again White
is picking between attacks against Black’s
rook (with Re6+) and a lesser piece (with
Rxb6+, attacking the bishop). Both targets are
unguarded at the moment, but Black can reply
to the check with Kf7, protecting the rook. So
Rxb6+ is better; it wins a pawn and a bishop
for nothing.
Dg377: White to move
Dg376: White to move
Dg376: It starts with identification of an idea:
the kernel of a discovered attack. Here you
find White’s rook blocking a check by his
queen. The only question is where the rook
Dg377: White has a tempting attack against
Black’s back rank: Black’s king is trapped in
the corner, and White’s queen is poised to
move to c8. Should it? The crucial thing to
recognize here is that the kernel of a discovery lies on the board—for Black. His rook
masks his bishop, which will check White’s
king as soon as the rook vacates f2. This is the
dominant tactical fact of this position, and it
makes Qc8+ a disaster for White; for then
Black plays Rf8+—not only blocking White’s
check, but winning his queen with RxQ as
soon as White takes his own king out of
check. White had better play Kh1 instead.
Dg378: Black to move
Dg379: White to move
Dg378: Now a reminder that a discovered
mate threat can be formidable, too. The
alignment of pieces on the d1-h5 diagonal
cries out for consideration of a discovered
attack; if Black moves his rook from e2, his
queen will threaten not only to take White’s
rook on d1 but to mate there—almost;
White’s queen presently guards the square.
The question for Black is the best use he
might make of his rook as it unmasks the
threat, and the natural answer is to go after the
White queen that protects the rook. He experiments with Rb2. If White plays the capture QxR, Black mates as just noted. Nor can
White move his queen to any other square
where it will prevent mate. The best he can do
is Qxd5, taking a pawn and guarding against
immediate mate by protecting the d1 square.
But then Black takes the queen with his c6
pawn (or with his own queen—it doesn’t matter) and White has nothing left but Rf1. Black
is ahead by a queen and has a won game.
He looks at any captures he can make and
considers their consequences—what lines
they would open and so forth. There is just
one: BxB, resulting in RxB. The interesting
feature of this exchange is that it not only
extinguishes the threat against White’s a1
rook but also leaves that rook and White’s
king with nothing between them—and an
enemy target on b2. White therefore can devastate Black by castling: 0-0-0. Suddenly
Black’s king has been checked by White’s
rook, while Black’s rook is about to be taken
for free by White’s king. Castling into an attack is not something you have a chance to do
very often, but when the opportunity arises it
is memorable.
The discovered attack here seemed at first to
be foiled by White’s queen, which appeared
to guard the targeted piece. Consider in such a
case whether the discovered attack might be
turned against the very piece that seems to
frustrate it.
Dg379: This position is not an especially
good fit for the current section because it does
not involve a discovery in the usual sense, but
it goes here as well as anyplace. White has to
do something about Black’s threat of BxR.
3.2.4. Manufacturing Discovered Check.
Now let's look at a few positions where some
element of the discovered check—open lines
or appropriate targets—has to be manufactured. The ideas behind the methods used here
will be familiar; only the context is any different from what has come before, but seeing
how the old ideas look in new settings will
make them easier to see in real time.
Dg380: Black to move
Dg381: White to move
Dg380: Find the makings of a discovered attack for Black in the position to the left. His
rook blocks his bishop along the g1-a7 diagonal. The bishop is aimed toward White's king
but is blocked by the pawn at f2. Black can't
capture the pawn and cause an interesting
recapture, so try another idea: capturing
something the pawn protects and thus forcing
it to move on the recapture. Viz.: Black plays
QxB, inviting f2xQ. If White plays the recapture, Black's discovered check has been nicely
prepared. All that remains is to find a good
target the d4 rook can reach in two moves.
Rd8+ unmasks check; then after White saves
his king, Black has RxQ.
Dg381: First find the kernel of a discovery;
you are trying to learn to see them every time,
even when they don't appear to lead anyplace.
White’s rook masks the path of his bishop
toward Black’s bishop—and, behind it, his
king. If Black’s bishop could be replaced
with his king, White would have the makings
of a discovered check. Capturing the bishop
would be one way to achieve this, but again
White has no way to do it; and yet again, too,
there is the alternative of capturing something
the bishop protects—the knight on h5. White
can take it with QxN+. If Black recaptures
BxQ, the bishop is out of the way and White
can unmask a check by moving his rook. He
looks for damage the rook can inflict with two
moves and sees that Black’s queen is within
reach. Rd6+ attacks it; RxQ takes it after
Black saves his king. White wins a piece.
Take a moment now to appreciate the threats
that Black faces in this position and how the
sequence just described would bear on them.
White has three pieces aimed near Black’s
king: his queen, rook, and bishop. Look at
White’s checks and you see that he is poised
to play Rxc7+. Black would have to play
BxR. Now comes the follow-up check QxB+,
forcing Black’s king onto a8; and finally
White mates with Qb8. Fortunately it’s not
White’s turn to move! The beauty of QxB for
Black is not only that it wins a piece by
threatening a discovered check; it also defuses
White’s threat against c7 by adding a guard to
the square (Black’s queen) and by taking out
one of the attackers against it (White’s
bishop).
Well, but wait: how does Black save his king?
He can move it (say, to g7); but he also can
save it with a threat by playing his bishop
from h5 back to g6, where it blocks the check
and also throws a counterattack at White’s
bishop. Now after White plays RxQ, Black
can play BxB. This would mean White traded
away a queen and a bishop to win a queen and
a knight—but we aren’t quite done yet. After
Black’s BxB, White recaptures with NxB and
still wins a piece. So the modest-looking
knight on e1 is necessary to make the whole
sequence work. (If that knight were off the
board, the sequence just described still would
be worth a pawn, though; after Black plays
BxB, White would have Rb5, forking the
loose pawns on a5 and c5.)
The lesson of this last note is to take time to
consider how your opponent will reply to the
checks you make. If it's clear that he will have
to move his king, it may not matter too much
where it goes (though then again it might!).
But if he has interpositions, you need to anticipate what they would make possible for
him on offense.
in the last position, the queen can be sacrificed to force the needed result: Qh1+, requiring KxQ.
Dg383: Black to move
Dg382: Black to move
Dg382: Black’s rook masks his bishop on the
long h1-a8 diagonal. This might be easy to
overlook because there is no White target at
the other end; but with the bishop aimed into
the corner next to White's king, you readily
should appreciate the potential for a discovered check here. The question is whether the
king can be drawn into the line of fire. One
way to so move a king is to check it with another piece. This is especially forceful when
the queen simply moves up next to the king,
requiring it to capture to survive; thus here
Black can play Qg2+, requiring KxQ. Since
this involved sacrificing a queen, you're looking for mate as a payoff; so Black wants to
move his rook where it can add to the pressure on White’s king (now on g2) that will be
created by the unmasked bishop on b7. The
rook can go two places to do this, both involving a capture: Rxf2 and Rxg3. The move
to f2 is unproductive since White just replies
KxR. Rxg3, however, is checkmate: the rook
has protection from the other Black bishop on
d6, and it cuts off the only squares the king
could use to escape the diagonal.
Dg383: A similar idea. Black has the familiar
kernel of a discovery on the long diagonal
leading toward White’s king. First the king
needs to be drawn onto the diagonal; here as
Now the rook’s job again is to both unmask a
check and add to the pressure on White’s
king. This it does with RxN++, putting the
king in double check and so requiring it to
move. Its only flight square is g1. Now Black
goes in for the kill with Rh1#. The bishop
protects the rook and also cuts off the king’s
flight square to the north—a classic mating
pattern we considered in the chapter on discoveries by the bishop.
Dg384: Black to move
Dg384: The kernel for Black again is the
bishop behind the rook, and again the
bishop’s path leads toward the position of
White’s king but not yet quite at White’s
king. How can the king be drawn onto the
bishop’s diagonal? With the same sacrificial
idea considered in the previous positions:
Qf2+, requiring White to play KxQ. Now
what? Again, with the queen sacrificed and
White’s king vulnerable, Black thinks in
terms of mate; this means using the rook to
add to the pressure on the king’s position by
making a check of its own or cutting off some
flight squares. Black could try a double check
with Rd2, but trace the consequences: the
king returns to the back rank with Kf1, and if
Black follows him there with Rd1, the rook
gets taken by White’s knight.
So what else might Black do with his rook?
The key here is to be mindful of all the Black
pieces bearing on the situation. After his
queen is off the board, Black still will have
another bishop at g4 cutting off the square
above White’s king (f3) and to the side (e2);
Black also has a pawn at f4 that cuts off e3
and g3 (well-advanced pawns can serve very
valuable purposes in closing off squares; do
not overlook them). This means that once
White’s king is drawn onto f2 it will have no
escape squares to the north, east, or west; the
third rank and the e2 square might as well be
filled with White pawns. So the really useful
thing Black’s rook can do is cut off the king’s
escape to the south by occupying the back
rank: Rd1+ unmasks check by the bishop and
leaves the king nowhere to go. White can interpose his bishop with Be3, but this just delays mate by a move (Black plays BxB#, with
his bishop getting cover from the f4 pawn).
Here’s another way to have seen the idea. As
Black you notice that your queen and bishop
both are aimed at f2, adjacent to White’s king.
You might naturally consider Rd1+; this requires a reply from White (NxR) to save his
king; and in the meantime the bishop has now
been unmasked and is ready to support mate
with Qf2. But then you see it doesn’t quite
work because once White’s knight is on d1 it
controls f2. So you play with the move order
and see that if you start with Qf2 it works
after all.
Dg385: Last, consider a case not of a discovered check but of a discovered mate threat.
First find the kernel for Black; it’s on the long
a1-h8 diagonal, where his rook masks his
queen. The queen's line would pass next to
White’s king without directly attacking it.
Black has no way to force White’s king onto,
say, b2, where it would be directly vulnerable
to a discovered check. So what to do? Think
carefully about where the queen would be
able to go, and with what results, especially
where the enemy king is as exposed as it is
here. Black’s queen would have some great
threatening squares to land on: think of c3 or
a1, where it would attack the king and cut off
most of its flight squares. And then remember
to consider the significance of other Black
pieces trained on the king’s sector—including
the bishop on g6, which slices off two more
of the king’s escape squares. The idea comes
into view: if Black’s rook unmasks his
queen—playing, presumably, Rxe2 and attacking White’s queen—Black’s queen would
not give check, but might threaten to mate.
Dg385: Black to move
Now nail down the details, imagining the particular moves and replies that would be possible. After playing Rxe2 Black is ready to take
White’s queen. If White plays QxR, then
what? Black plays Qc3, which has become
safe now that White’s queen has moved over
to take the rook—and it’s mate (after White
uselessly interposes his queen), since White’s
king has no place to go.
In reply to Black's initial Rxe2, White’s preference would be to move his queen someplace
where it both is safe and prevents mate, but
no such square is available; in fact there is
nothing at all he can do with his queen to
avoid mate. Instead he has to play RxBg6,
extinguishing the mate threat—but surrendering his queen next turn (or the turn after that
if Black first plays Qa1+).
3.2.5. Two-steppers: Building the Kernel.
Dg387: White to move
Dg386: Black to move
Dg386: Here Black does not have the kernel
of a discovered attack; the point of the position is that when you see a configuration like
this—bishop and rook coordinated, with both
trained on squares near the king—it pays to
experiment with creating the pattern for a
discovery by bringing one piece into the path
of the other and examining the consequences.
Here an obvious way would be Rc2+: the
rook moves into the bishop’s path and gives
check; White’s king has to move. If it goes
anywhere but d1, it leaves the knight loose
and Black takes it with his rook on the next
move. (Always ask whether an opponent’s
forced move would leave anything loose.) If
White moves the king to d1 to protect the
knight, he completes the pattern for a discovered check by putting it on the same diagonal
as Black’s bishop. Now Black would think
about what he could do with his rook in two
moves. Don’t obsess over the knight. Think
broadly about the opportunities created by a
discovered check; look for any White piece
Black could attack with his rook in two
moves. Rc7+ would unmask check by Black’s
bishop, and attack—and then win —White’s
rook on h7.
Dg387: White is nervous; his king is trapped
in the corner with Black’s queen and bishop
trained on its general position though not perfectly coordinated. Plus White's rook may be
lost if he removes his queen’s protection of it.
What to do?
Look for queen moves that continue to protect
the rook and also add pressure against Black.
One such move is 1. Qd5, since it not only
attacks Black’s bishop while still protecting
the rook but also creates the three-piece kernel of a discovered check, enlarging the
power of both queen and rook. Indeed, this
move wins the game:
(a) If Black plays 1. …Qc1+, hoping to divert
White’s energies by taking the offensive,
White executes the discovered check with 2.
Rf1+, blocking the check against his own
king and preparing to take Black’s queen after
Black moves his king out of check. (Actually,
after 2. Rf1+ it goes 2. …Kg7, 3. QxB+, and
then White plays RxQ. Black’s queen will
remain en prise to White’s rook so long as
White keeps checking Black’s king with his
queen and doing other damage with it in the
meantime. The priority of check.)
(b) If Black instead plays Qc6 as his initial
response, pinning White's queen, he of course
loses his own queen to QxQ. Yes, this capture
allows Black to play KxR, but then White
plays Qd5+ and wins Black’s bishop with a
queen fork. White’s queen is the only piece
left when the smoke clears.
and the bishop on g2 still has protection. The
king’s only legal escape is to h2—and then
play proceeds as described a moment ago,
with Bf3+ discovering check and then winning White’s queen.
Dg388: Black to move
Dg388: Black is closing in on White’s king. A
key feature of the position is the kernel of a
discovery on the diagonal leading to g1; keep
it in mind as you go through your thought
experiments. The natural moves to consider
first are any checks. Black has two: Rh2,
which loses the rook without compensation;
and Bg2, which is a lot more interesting because the bishop enjoys protection from the
rook on f2, forcing White’s king to move.
Where would it go? It would have two options: h2 and g1. Consider them both:
(a) If White plays Kh2, notice that the king
would have made itself the target of another
discovered check—using the kernel Black
created when he moved his bishop in front of
his rook. Black would be able to unmask a
check by moving his bishop from g2, and so
can think about targets the bishop might reach
in two moves. The natural candidate is
White’s queen. Hence Bf3+; and after White
moves his king, Black has BxQ.
(b) Now suppose that in reply to Bg2 White
plays not Kh2 but Kg1. Again the king would
have walked onto the target square of a discovered check, this time the one whose kernel
was in place from the beginning. It would be
tempting now to play Rf5+, unmasking check
and then winning White’s queen in exchange
for a bishop after White plays KxBg2. But
don’t jump to conclusions; there may be a less
costly way to achieve the result. It would be
preferable to first force White's king to h2 and
then use the discovered check described in the
previous paragraph. How? With another
check: after White plays Kg2, Black replies
Rxe2+. The bishop on e3 now gives check
Dg389: Black to move
Dg389: The kernel of the discovery for Black
no doubt is obvious: the rook on d3 masks the
queen on e2, which otherwise would take
White’s queen. The question is what threat
the rook can make when it moves. Since it has
no checks, think about other ways it can put
pressure on White’s king—always keeping in
mind any other pieces you have that also bear
on the king’s position, since pressuring the
king usually requires a team effort. Here
Black has a bishop aimed at White's king on
the long diagonal, blocked just by the pawn
on f3. What would it take to create checkmate
from here? If the f3 pawn were eliminated
and the rook were added to the assault against
the king, that would do it. So Black plays
Rxf3. This unmasks QxQ, of course; it also
leads to mate when the rook next drops down
and plays RxN#—a case not only of discovered check but of double check. White has a
move to make after Rxf3, but no way to prevent the result.
Notice here that when Black unmasks one
discovery he also uses the unmasking piece to
set up another one; he moves the rook out of
the queen’s path and into the bishop’s path,
creating a mating threat. The point: when you
have multiple pieces aimed in the enemy
king’s vicinity, don’t just look for existing
discoveries. Think, too, about how various
checks, captures, and threats you might make
would create new kernels and new potential
discoveries. Indeed, anytime you move your
pieces you want to be careful to notice
whether you are bringing one into the path of
another, for now you appreciate the power
conferred on pieces when combined in this
way.
Dg390: White to move
Dg390: Where does White have the makings
of a discovered attack? On the a3-f8 diagonal,
where the bishop is masked by the rook—and
otherwise would check Black’s king. Naturally White thinks about moving the rook out
of the way, not only to do damage elsewhere
but perhaps also to create checkmate by starting with a double check. How can the rook
both unmask the bishop and give check itself?
With Re8++ or with Rxf7++. Let’s consider
each of them:
(a) Rxf7++ might seem more appealing because the rook is safe there, enjoying protection from the queen on d5. There is an additional point: with Rxf7++ the rook moves into
the queen’s diagonal path, creating the kernel
of another discovery—a potentially useful
pattern. Follow the king’s path in response. It
would have to go either to e8 or g8. If Ke8,
White would have the new check Qd7#, with
the queen and rook protecting each other and
cutting off all the king’s flight squares.
Now suppose Black plays not Ke8 but Kg8.
He would have completed the pattern for a
discovered check—the new one that White
started to create with Rxf7; the king would be
on the same diagonal as White’s queen. So
White moves his rook out of the way, unmasking another check, and once more he
looks for ways the rook can add another
check of its own. The simple Rf8 is mate,
with the rook getting cover from the bishop
on a3—another study in the importance of
remembering how all of your pieces may bear
on a position. Once again, too, we see how a
piece can unmask one discovered check while
also moving into position to unmask another,
as White's rook does here.
(b)From the initial diagram we also can consider the double check Re8++. Black is forced
to play KxR. White’s attack might now seem
to be out of gas—if you overlook the rook on
b1. But it can add decisively by sliding over
to the open e-file and giving check. Notice
that Black’s king has no safe moves; each of
its flight squares is under attack. All Black
can do is throw his bishop and then his queen
into the White rook’s path, but they are useless interpositions; White plays RxB and then
RxQ#.
3.2.6. The Windmill.
And now one of the most exquisite of all tactical motifs: the windmill. A windmill generally involves a series of discovered checks in
which the masked piece and the unmasking
piece take turns checking the enemy king; the
masking piece, on its “off” turns, captures one
enemy piece after another. (This will become
clearer in a minute.) Although a windmill can
in principle occur with other pieces, the ones
you are most likely to see involve a rook discovering check by a bishop; that is why the
motif is included in this chapter. These also
typically are cases where the kernel of the
discovery does not exist at the outset of the
sequence. It has to be built, and in the building of it the enemy king is forced into position
for a discovered check. This, too, will be easier to grasp once it is seen.
Dg391: Black to move
Dg391: Begin with the simple and modest use
of the idea to the diagram. Black has the kernel of a discovered check: his rook masks his
bishop’s path to White’s king. Black just
needs a good target for his rook. White’s rook
won’t do; for after Rf2+, White moves his
king to g1, protecting the rook as well as
evading the check. Black needs a target farther away. The bishop and pawn on the other
side of the board protect each other; does it
matter? No. Black plays Rxa2+, taking the
pawn; White is required to play Kg1 (the
king's only flight square); and now Black
brings the rook back to g2 with check. Now
the key point: White has to move his king
back to h1, and suddenly the position has
been reset to the beginning with Black ready
this time to go after a fresh target—White’s
bishop, now left unprotected. Black plays
Rb2+, and after White moves his king back to
g1, Black plays RxB. A simple instance of a
windmill.
path with check via Rxg7+, forcing Black’s
king to move to h8. Notice how the position
of Black’s king parallels the position of
White’s king in the previous example: it is
about to be hit by a discovered check, and it
has just one flight square. White unmasks a
bishop check and at the same time takes
Black’s bishop with RxB. Black has to move
his king to g8. Then White returns his rook to
g7, forcing Black's king back to h8—and resetting the pattern. Again White unmasks the
bishop, and this time he takes Black’s knight
with RxN+. Black moves his king back to g8,
and so forth. White just slides his rook back
and forth, alternately putting Black’s king in
check and cleaning out Black's holdings on
the seventh rank. Since every White move
puts Black back in check, he has no time to
stop the carnage. After White finally reaches
Black’s second bishop with RxBa7, and Black
moves his king yet again to g8, White this
time does not return to check the king; he
instead administers the coup de grace with
RxQ.
Dg393: White to move
Dg392: White to move
Dg392: Now a more dramatic use of the same
logic. Does White have the kernel of a discovered attack? Not yet; but he can form the
kernel by moving his rook into his bishop’s
Dg393: Start by noticing the same rough starting pattern here as in the previous position:
White has vertical pressure against g7 and a
bishop pointed at the same square. He can
give check and form the kernel of a discovery
by capturing there with a heavy piece. This
time White can’t just take the pawn on g7 and
start rolling; the pawn is guarded by the
knight on f5. But White has a piece he can
sacrifice to the cause: his queen. So 1. Qxg7,
NxQ and now the pattern here more precisely
resembles the previous one. White plays
RxN+, accomplishing two things: the move
checks the king, forcing it onto its only flight
square—h8; and it sets the pattern for a discovered check by moving White’s rook into
his bishop’s path and forcing Black’s king
onto the same diagonal. A windmill is in
place. If White moves his rook, the king will
be in check and move back to g8; then if
White brings his rook back to g7, the king
will be in check again and will move back to
h8.
How to exploit this? White first explores the
usual destructive options on the seventh rank
with RxB+, discovering check. Black plays
Kg8; White plays Rg7+; Black plays Kh8,
and the pattern is reset. After White has taken
both Black pawns on the seventh rank, White
will use the two rook moves made possible by
his discovered check not to return to g7 but to
reach Black’s queen, just as in the previous
problem: he plays Rb7+; Black plays the
compulsory Kg8; and now White plays RxQ.
White nets two pieces and three pawns with
the sequence.
now can move his rook to and fro, repeatedly
giving check and inflicting terrible losses as
he goes. He starts with the customary liquidation of Black’s seventh rank, discovering
check with 3. Rxf7. From there the moves
went 3. …Kg8; 4. Rg7+, Kh8; 5. RxB+, Kg8;
6. Rg7+, Kh8; 7. Rg5+, Kh7; 8. RxQ, and
White won.
Usually windmills occur with the king on the
back rank and a rook discovering check
against it while roaming back and forth on the
next rank forward. But they also can run in
the other direction, with the rook running
amok up and down a file.
Dg395: White to move
Dg394: White to move
Dg394: Here is the most famous of all windmills, delivered by Carlos Torre against
Emanuel Lasker in 1925. Again a short setup
is necessary. White plays 1. Bf6, dramatically
sacrificing his queen to 1. …QxQ. The sacrifice is justified by the pattern the move creates: his bishop and rook are trained on the
square in front of Black's king, which has a
small range of motion. The windmill is ready
to turn: 2. Rxg7+, and Black has to play 2.
…Kh8; meanwhile White has moved his rook
into his bishop’s path, readying a discovered
check against Black’s king in its new position. We have seen this before. Since Black’s
king has no squares except g8 and h8, White
Dg395: In this position there again is no kernel of a discovery yet in place for White. But
Qg7+ is a natural move to consider; it’s close
to checkmate, as it moves a protected queen
up next to Black’s king. Black’s only legal
response is RxQ. Now the stage is set for the
creation of a windmill: White has a rook and
bishop pointed at the square in front of
Black's king, which has little room to move.
Thus RxRg7+ leaves Black’s king only one
place to go—h8—and also sets up discovered
check by masking White’s b2 bishop with his
rook. By sliding his rook back and forth between g7 and various Black targets, White
can create havoc while Black stays busy fending off checks. It starts with RxBg6+; Black's
king is forced to h7. White plays Rg7+, and
Black has to move his king back to h8, resetting the pattern. Now what? White plays
Rxh6—and it’s checkmate. A familiar lesson
repeats: never forget that your first objective,
where possible, is not to take material but to
mate.
Now note a possible wrinkle. After White’s
first exploits the windmill with RxB+, Black
has another option besides moving his king
back to h7. He can interpose his f8 rook at f6,
blocking the check from White’s bishop. The
interposing rook is guarded by its queen, but
that is not security enough because at this
point White attacks f6 twice—with both his
bishop and his rook. Thus White replies BxR;
Black recaptures QxB; and now Black loses
his queen to RxQ. Black has no pieces left,
while White still has his rooks and can force
mate soon. But it’s worth seeing the general
point, which is that when Black interposes
rather than playing into White’s hands by
moving his king, he may unexpectedly disrupt
the flow of the windmill. In another game this
sort of interposition might save a game rather
than just forestalling doom.
Dg396: White to move
Dg396: White does not yet have the makings
of a discovery, but he can create the kernel of
one by moving his rook into his bishop’s path.
Both pieces are aimed at the square in front of
Black's king, so the rook's move to g7 gives
check and may create a windmill. May, and
does. In the previous positions the trapped
king had to shuffle between two squares because all others were blocked by the side of
the board or by its own pieces. Here Black’s
king is hemmed in by White’s knight on d6,
which cuts off e8 and f7. So when White
moves his rook from g7 and discovers check,
Black’s king will have to go to g8; and when
White moves his rook back to g7, Black’s
king will have to return to f8.
The only question is what White should do
with his rook to make the most of this pleas-
ant opportunity. He starts with the familiar
destruction of the seventh rank: Rxd7+ (Black
plays Kg8), Rg7+ (Black plays Kf8). Now
what? Rb7+ (Black plays Kg8); and now
RxR+, winning a rook and applying another
check from a different angle. Black has no
escape from it; all his flight squares are attacked. All he can do is interpose Nf8, but
then RxN#. We see again the importance of
remembering to look not just for material but
for mate.
Knight Discoveries.
3.3.1. Diagonal Patterns.
The knight is without peer as an unmasker of
attacks. The reason is that a piece generally
cannot unmask an effective attack if it moves
in the same direction as the piece it is unmasking. Hence rooks can unmask attacks by
bishops, but not by other rooks; and a queen
usually can’t unmask any sort of attack, because it can move in all the same ways as any
of the pieces it might uncover. But the knight
doesn’t move like any other piece on the
board. It jumps rather than slides. Knights
therefore are equally able to unmask diagonal
attacks by bishops, vertical or horizontal attacks by rooks, and attacks of either sort by
the queen. Plus the knight is a piece with a
relatively low value, enabling it to be sacrificed readily for other gains. If you don’t
know how to use your knight to unmask attacks by other pieces, you don’t know how to
use your knight.
Dg397: White to move
Dg397: We begin with the knight's power to
uncover diagonal attacks. In the position to
the left, the sight of White’s knight in front of
his queen (as well as his rook) should cause
immediate thoughts of a discovery; Black's
queen is loose, so White will be able to play
QxQ if he can find a time-consuming move
for his knight to make. The classic timeconsuming move—and usually the necessary
one when you hope to win the queen—is a
check. White has two with the knight: Ne7,
which ruins everything as Black plays QxN,
and Nh6, which requires Kh8 and thus wins
Black’s queen a move later.
Dg399: See how White’s f4 knight masks his
queen. See that Black’s queen is loose. See
how the knight can give check in one move
(Ne6+). All the ingredients of a discovery
thus are in place. The check looks harmless
because it is so easily defused with BxN or
f7xN; but by then it has served its purpose,
which was to gain time to allow White to play
QxQ+.
Dg400: White to move
Dg398: White to move
Dg398: Find the kernel of the discovery. The
pattern of knight-masking-bishop triggers
thoughts of a discovered attack. If unmasked
by the knight on g4, the bishop has an ideal
target in Black’s queen. Also ideal is the
knight’s target: it can give check with 1.
Nf6+. It doesn't matter that Black can address
the threat in various ways; he loses his queen
in any event. Thus if 1. Nf6+, g7xN, then 2.
BxQ; and if 1. Nf6+, QxN, then 2. NxQ+.
Dg399: White to move
Dg400: You want to spot the kernel of a discovery every time it exists. Here White’s
knight masks his queen (don’t be distracted
by the queen's backward path of attack).
Black’s queen is loose, and so makes a perfect
target; White’s knight will give check, and
then White will play QxQ.
But which check should the knight give: Nd5
or Ng8? When there are two checking options, as there often are with a knight, carefully consider them both. Start by asking how
Black would reply to Ng8. His only capture
would be Ra8xN. Visualize that move and
notice that it pins White’s queen to his king
(the alignment of White’s king and queen is a
conspicuous feature of the position). White
then can play QxR, but not QxQ—and now
Black has QxRa1+. So Ng8+ doesn’t work.
Now consider Nd5+. It leads to RxN or e6xN,
either of which is okay with White; he plays
QxQ regardless, ending up with a material
advantage after starting the position behind by
one rook and threatened with the loss of another.
3.3.2. Vertical and Horizontal Patterns.
Dg401: Black to move
Dg401: Find the kernel of the discovery for
Black. His knight masks his queen, which
otherwise is aimed at White’s loose queen.
(The knight also masks the rook on e8, which
lacks a promising target. When you have a
knight in the center, be mindful of how it may
mask attacks in all directions.) If Black’s
knight could give check, he could play QxQ;
but it can’t. Nor can the knight create a mating threat, nor can it capture anything. So
consider whether it can make any other good
threats. None of White’s other pieces are
loose, but the rook on f3 would make a nice
target for a knight regardless of whether it’s
protected. So play with a move that attacks it:
Ng5. White finds both his queen and rook
attacked. If he moves one out of harm’s way,
the other gets taken. He thus would play QxQ,
a luxury permitted by the fact that Black’s
unmasking piece didn’t give check. But now
Black doesn’t play the recapture h7xQ; he
plays NxR+—and then, after White captures
on f3, Black has h7xQ, winning the exchange
with the sequence.
This is another of many examples of taking
advantage of the priority of check—the requirement that checks be addressed regardless
of what else is happening on the board. Before you play a natural recapture, consider
whether you have other damage you can do
first with a check, postponing the recapture
until a little later. In this case the discovery
only turns a profit because Black can take
White's rook with check.
Dg402: White to move
Dg402: This position introduces a new type of
kernel to absorb: the knight in front of a
heavy piece (a queen or rook) on the same
file. If White's knight can vacate its square
with a check, White’s queen will be able to
take Black’s queen, which is loose. White
thus plays Nxf6+—a fork of Black’s king and
queen. Black has to fend off the check with
g7xN; and now the game effectively ends
with QxQ+. (If Black instead replies to Nxf6+
with Kf8, then it might seem that White
would simply play NxQ, but he can do better:
Qxe8#. Notice, too, that with Nxf6 the knight
seals off h7 as a flight square.)
Dg403: Black to move
Dg403: The kernel in slightly different visual
form, with Black’s rook masked by the knight
at the other end of the e-file. The White rook
on e1 is unprotected, making it a suitable target. As usual the knight’s first choice of threat
is a check, this time with Ng3+. After h2xN,
RxR wins the exchange.
Black also could try replying to 1. Nxd5 with
1. ...QxN, which protects his bishop on c5,
but the protection doesn't last long: White
plays QxQ, and then (after Black's recapture)
still has RxB. All this now leaves Black with
the kernel of a discovery against White on the
c-file: his knight masks his rook. But the
knight does not have a sufficiently threatening
move to make, so the whole sequence is safe
for White to play.
Dg404: White to move
Dg404: Find the kernel of a discovery for
White. This time it runs horizontally: White’s
knight masks his queen’s path along the third
rank. The point: your routine scan of the
board needs to include attention to any
friendly pieces on the same diagonal or rank
or file as the knight. Here Black’s queen is
loose, and White wins it with QxQ by first
evacuating the knight from f3 with a check—
i.e., Ng5+.
Dg405: White to move
Dg405: The White knight in front of his rook
on the c-file should prompt thoughts of a discovery. Does the rook have a good target? It
does: the bishop on c5 is loose. All that remains is to move the knight out of the way in
a sufficiently threatening or profitable manner. The knight has no checks or other threats
to make against Black’s king. But since White
is going to take a piece at the end of the sequence, he can afford to sacrifice the knight
for any lesser gain of material and still come
out ahead. Thus 1. Nxd5, BxN, and now 2.
RxB nets a pawn. (One can’t expect to win a
whole piece every time.) Or Black replies to
1. Nxd5 with Nf6-e4, letting go of the pawn
but protecting the bishop on c5.
Dg406: Black to move
Dg406: Find the kernel of a discovery for
Black. There are a few of them: Black’s
knight on e6 masks the bishop on c8 and the
vertical path of the queen on e7; his knight on
f6 masks the queen’s diagonal path toward
h4. Your first thought is to see if any of those
discoveries has a good target at the end of it,
and this leads you to the loose White knight
on e5. Black will take it for free with his
queen if he can find something violent enough
for his knight to do as it jumps out of the way.
Checks always are attractive for the purpose,
but here none are available. So what else can
the knight do? Examine its circle of moves, or
consider whether White has any other loose
pieces; either way you are led to Nc7, attacking the bishop on b5 as well as discovering an
attack against White's knight.
knight’s other possible squares and notice
Nc6: a move that both attacks Black’s queen
and keeps the White knight safe. Black moves
his queen, and White has QxN for free on his
next move.
Dg407: White to move
Dg407: White’s knight masks his queen. The
knight is not on the same color square as
Black’s king, so it won’t be able to give
check; and the queen’s natural target, the rook
on e8, has protection. So study the knight’s
circle of moves and ask what other offensive
blows it might be able to strike. Its most interesting move is 1. NxB, a capture that
threatens Black’s queen. Consider each of
Black’s possible responses and then White’s
replies. If 1. ...RxN, then now the rook on e8
is loose and White plays QxR. If Black instead plays 1. ...RxQ, White has NxQ+. Either
way White gains an edge in material.
Dg409: Black to move
Dg409: Now a glance at our current topic
from a defensive standpoint. Black needs to
move his queen to avoid b4xQ, so he considers Qxa3, which seems to win a loose pawn.
But before making a venture like this, especially into enemy territory, look for any tactical ideas your opponent may have in place.
Where does White have the kernel of a discovery? The sight of his knight masking his
rook on the third rank is cause for alarm; if
Black plays Qxa3, White can attack Black’s
king and queen at the same time with the
crushing horizontal discovery Nd5+.
3.3.3. Building Knight Discoveries.
Dg408: White to move
Dg408: Where does White have the makings
of a discovery? On both the d-file and e-file,
where his knights mask his queen and rook
respectively. Look for targets for the masked
pieces and you see that on the d-file there is a
loose Black knight. All White needs is a good
threat for his knight to make as it uncloaks the
queen. You might first look at checks and find
Ne6; but then what? The knight is lost after
f7xN, and then if White plays QxN Black has
e6xQ—not good! But then look at the
Dg410: Black to move
Dg410: In knight discoveries, as with any
other sort, groundwork often must be laid:
targets improved or lines cleared with preliminary exchanges. Start with the study on
the left. One of the advantages of a fianchettoed bishop (i.e., a bishop positioned like
Black's on g7 here) is that if the knight comes
to rest naturally on f6 (or, for White, f3),
Black has the kernel of a discovered attack
against the middle of the board. The pattern
works especially well where, as here, the enemy king has been drawn off the back rank
onto f2 or h2; for now the knight can give
check with one move. All Black needs is a
suitable target for the bishop once unmasked.
The protected White bishop now on d4 won’t
do, so Black plays an exchange to upgrade it:
1. …RxB, 2. QxR and now the board is arranged for Black to take White’s queen with
the discovery Ng4+. (If White is alert he will
reply to RxB by retreating his queen to c1
rather than by playing the recapture
QxR,naturally preferring to forfeit his bishop
rather than lose his queen and face the additional trouble that follows afterwards.)
Dg411: Black to move
Dg411: Find the kernel of a discovery for
Black. His queen is masked by the knight on
c6; his bishop, as in the previous case, is
masked by the knight on f6. So now think
about the targets available for the masked
pieces. The knight on c3 is protected by a
pawn, making it an unappetizing target for
Black’s queen. But the knight on d4 is another
matter. It is protected once, but by White’s
queen; and it is attacked once already by
Black’s knight on c6. This suggests two sorts
of possibilities: play the discovery with Ng4+
(the same idea seen in the previous problem);
then after the knight gets taken, play BxN.
But of course this move order gains nothing.
It’s just a trade of pieces. So consider the
other move order: play the exchange NxN
first; if White replies QxN, play the discovery
Ng4+, winning the queen. Again, a preliminary exchange serves to upgrade the target.
Dg412: Black to move
Dg412: Here is an alternative sequence. The
kernel is similar: the fianchettoed bishop with
a knight in front of it on f6. Again the target is
a White knight on d4; again that knight is
protected once and attacked once; again Black
has to decide whether to execute the discovery now or do a preliminary exchange first.
One difference is that White’s king is not
available as a target. Another is that in the
previous problem White was defending the
targeted knight with a very valuable piece (his
queen) and Black was attacking it with a
piece that was less valuable (his own knight);
so it made sense to make the preliminary exchange first, turn the queen into a target, and
then play the discovered attack against it.
Here the situation is reversed. White guards
his knight with another knight, and Black
attacks the targeted knight already with his
queen. If Black plays the preliminary exchange QxN first, he loses his queen and
doesn’t improve the target. So here he skips
the preliminary exchange and just plays the
discovery Nxe4. If White replies f3xN, Black
has BxN and nets a pawn. If White then takes
the bishop with his e2 knight, Black recaptures with his queen.
Notice that with the sequence Black has spent
his dark-squared bishop, which was doing
important defensive work (look at all the vulnerable dark squares near Black’s king; Black
no longer has a bishop to patrol them). From
Black's standpoint the wisdom of giving up
that bishop to gain a pawn is not clear-cut;
some strong players might therefore conclude
that the sequence just described wasn’t
Black’s best move after all—though it was
what Bobby Fischer played in Surgies-Fischer
(1957).
Dg413: White to move
Dg413: This position requires the same type
of decision yet again. It is White who has the
makings of a discovered attack a couple of
different ways; his queen’s path is masked in
one direction by his bishop and in another by
his knight. The direction of greatest interest is
the one with a good target at the end of it, so
White focuses on Black’s knight on d5. It's
attacked once and defended once. If White
were to give check with his own knight—say,
with Nxf6—he could then take the d5 knight
with his rook. But his own knight would be
lost in the process, resulting in a gain of only
a pawn. Since the Black knight is guarded by
Black’s queen, which would make a perfect
target, the better sequence thus starts with a
preliminary exchange: 1. RxN—and now if
Black plays QxR, White has the discovered
attack Nxf6+, taking Black's queen and turning a tidier profit.
Dg414: White to move
Dg414: Two patterns here should attract your
attention: the masking of White’s bishop by
his knight, and the battery of White rooks on
the d-file. Since White’s knight can give
check on h6 while unmasking the bishop,
everything is in place for a discovery—except
a suitable target for the bishop to attack. The
knight on d7 won’t do; after 1. Nh6+, g7xN;
2. BxN, White hasn't won anything. So upgrade the target by capturing it with another
piece—and then doing it a second time if necessary. Hence the usefulness of having the
two rooks on the same file: 1. RxN, NxR; 2.
RxN, QxR, and now White has created a worthy target for his bishop. Nh6+ wins the queen
after Black fends off the check. In practice, of
course, Black probably would play Qb6 on
his second move rather than walk into the
discovery, in which case White will have won
two pieces for a rook.
Dg415: White to move
Dg415: The potential for a discovered attack
is obvious enough: the e4 knight will give
check by moving to f6; then White’s queen
will take Black’s queen. But now inspect both
targets in search of any obstacles to the idea's
smooth execution. Black’s queen is guarded
by his knight. You might like to deal with this
by capturing the knight, of course, but how?
Consider all the White pieces. The rook on d1
is aimed at the bothersome knight; and the
knight is next to Black’s king, which also is
suggestive. Play with sequences that would
allow the rook to help. First move the bishop
out of its way violently, with 1. BxN, g7xB.
Now move order becomes important:
If White starts with 2. RxN+, he takes out the
queen's guard but ruins the discovery he is
planning: Black plays KxR, and now White's
3. Nxf6 would no longer give check. So
White should instead play 2. Nxf6+. Then
Black takes the knight with 2. …BxN; and
now rather than 3. QxQ, White plays 3.
RxN+. The priority of check requires Black to
attend to this threat to his king while the
threat of QxQ hangs in the background; after
KxR (or RxR or BxR), the guardian of
Black’s queen is gone and White takes it on
the next move. The point: the queen's guard
must be taken out late, not early, if the structure of the discovery is to be kept in place.
Notice that after White plays QxQ at the end,
Black now has a remaining capture: BxNg5.
You therefore must be careful to keep track of
your gains and losses. White has gained two
knights and lost two knights. He also has lost
a bishop and a rook, but in return he has won
a queen and two pawns—a good trade.
Another, simpler way to look at this position
is that White just plays the discovery NxN+,
but (a) first sets it up with a preliminary capture (BxN) and then (b) interposes a checking
move (RxN+) in the middle of it. Since
checks require forced replies, it sometimes is
possible to sneak them into a sequence like
this with no loss of time. But White can't slip
in that capture until he gets his own bishop off
the d-file; that's why we have (a) here as well
as (b).
Dg416: Black to move
Dg416: We turn from exchanges that upgrade
or loosen a target to exchanges that draw a
target into position. We saw earlier that a
king’s knight in its natural first position—
here, on f6—often can give check while unmasking an attack if the enemy king can be
drawn forward onto the second rank. Here is
another example. Notice the kernel of a discovery: Black’s f6 knight masks his queen.
Examine the queen’s possible target and see
that the bishop on g5 is loose; it appears to be
pinning Black’s knight to his queen, but its
unprotected status makes it possible to turn
the tables. Black just needs a target for his
knight to attack as it moves out of the queen’s
way. As yet it has nothing; but Black looks
for any check he can give and finds Bxf2. If
White responds with Kxf2, now Black plays
the discovery Ng4+ and wins back the bishop
with QxB on his next move, netting a pawn
and damaging White’s defenses with the sequence. (If White replies initially with Kd2
rather than KxB, White has achieved a similar
result more simply.)
3.3.4. Working with Mate Threats.
Sometimes you may have the makings of a
discovery but lack anything good for the
knight to do when it unmasks the other piece;
you would like to give check but aren't within
range, and the knight has no obvious threats
to make against other pieces either. Remember, then, another idea: look at the enemy
king; see its vulnerabilities, and any pieces
you have bearing down on its position. Sometimes adding the knight to those other pieces
can create a threat of mate or other serious
trouble that can anchor a discovered attack as
effectively as a check. The point can be put
more generally. You already know it is important to look for checks and to create ways
to give them. It also is important to watch
for—and create—mating threats, as they often
serve similar purposes just as well and are
easier to devise. Just aiming a piece at a
square next to the enemy king may be enough
to create a useful mating threat a move later
when you aim a second piece at the same
square—and aim it at a loose enemy piece at
the same time.
Dg417: White to move
Dg417: In this first position, White has a classic arrangement for a discovered attack: his
knight masks his fianchettoed bishop, which
otherwise could take the loose Black bishop
on b7. But what threat can White make with
his knight that will keep Black busy? The
knight seems far from any targets, and certainly can’t give check from where it now sits.
The key is to examine Black’s king and notice
that White’s queen already is aimed at a
square next to it: h7. If White plays Ng5 his
knight adds more pressure to h7, and now
White is a move from mate with Qxh7. (The
simple pattern of a knight on g5 supporting a
mate threat by a queen aimed at h7 is familiar
and should be absorbed.) So Ng5 is as effective as a check; Black is equally required to
pause to fend off the threat. He will do it with
QxN, of course. That then leaves White to
play BxB. Is the trade of pieces a wash? No,
because Black’s rook is stuck on a8, and will
be taken by White on his next move.
Dg418: White to move
Dg418: White’s knight masks his queen,
which otherwise could take the loose rook on
a7. The only question is what White’s knight
might do while unmasking the attack. It can’t
give check, but might it again add to a threat
against a square next to Black's king that already is under attack? Yes: White’s queen is
aimed at g7, and the knight can add more
pressure to the square with Ne6. Now White
has Qxg7# if Black tries to save his rook, so
Black instead has to fend off the mating threat
and let the rook go on the next move, losing
the exchange. White's 1. Ne6 is as good as a
check.
Dg419: White to move
Dg419: The kernel of the discovery is clear:
White’s knight masks his queen. Where can
the knight go, and what can the queen then
attack? The general answer should be clear
from the look of the board: the knight can
head in the king’s direction, and then so can
the queen; with a single move of the knight
they both can attack h7. Meanwhile White’s
rook already attacks that square. With three
pieces ready to bear down on the territory of
Black’s king, think in terms not of material
but of mate. Consider Nf6; imagine each pos-
sible response by Black, and each check
White would have afterwards. You will find
that no matter what Black plays—e.g., NxQ,
or g7xN, or RxN, or h7-h6, or g7-g6—White
is then able to play either Qxh7# (supported
by the knight or rook), or Rxh7# (supported
by the knight). It's nevertheless important to
notice all of those possibilities.
The point: you can use a discovered attack not
only to win material but to mate.
You might have come at the position a bit
differently. White is in a hole; he is down two
pieces (though ahead two pawns). He needs to
make something happen. The obvious focus
of his attention is h7, where his rook and
queen are aimed. A natural thought is Rxh7+,
with the double check Nf6++ or Ng5++ to
follow if Black replies KxR. But you don’t
play a sacrifice like that unless you are sure it
works, and as it turns out the double check
doesn't end up achieving enough to save
White. So you experiment with different
move orders that likewise attack h7 and realize that Nf6 is not only strong but conclusive.
tion from which it could attack the king a
move later? If so, that move might be as menacing as a check, given the constraints on the
king’s mobility. Here the knight can move
toward the king with Nd5—and a move later
White then would be able to play Ne7#. Nd5
therefore is as effective as a check; Black
must parry the threat or the game is over. But
then it pretty much is over in any event because White plays QxQ.
This position is a nice study in how even a
knight that seems very far from the enemy
king may have the power to make a mortal
threat against it. It also illustrates the importance of watching the vulnerabilities of the
kings at all times, no matter how distant they
may seem from the rest of the action.
Dg421: White to move
Dg421: "And what checks would I then
have?" Learning to ask this question consistently is one of the secrets of great chess. This
position offers two illustrations.
Dg420: White to move
Dg420: White's c3 knight masks his queen,
which otherwise could play QxQ. But for a
discovery like this to work, the knight needs
to threaten something even more valuable
than the queen—viz., the king. Yet how? The
knight is on c3, very far from the Black king
on g8. Still, examine the king’s position
closely. White’s bishop on h6 cuts off the
king’s escape squares entirely; if the king
were attacked it would have nowhere to go
and might be mated. White can’t attack it
now, but might he move the knight to a posi-
The idea here is similar to the previous position but with a slight upgrade in complexity.
Again White’s knight prevents him from
playing QxQ; again the knight is not yet in
position to give check; and again Black’s king
is hemmed into the corner by the bishop on
h6. The question is whether the knight on d4
can take advantage of the king’s vulnerability
in a way that requires Black to make a timeconsuming reply. As in the previous position,
look for places the knight can move that
would place it one move away from giving
check, and then consider the consequences of
that potential check to see how bad it would
be for Black.
Here the knight can start by moving to c6
(with a capture) and then be a move away
from Ne7+—while also unmasking the threat
of QxQ. Suppose Black replies with QxQ, and
now White plays NxNe7+. How serious a
threat would that be? Black’s only legal move
would be Kh8; White looks for his next check
and finds that he can mate by bringing in another piece: he moves his g5 knight to f7. So
if White starts with NxNc6, Black can’t afford to play QxQ. Can he afford to instead
play QxNc6? That seems to extinguish
White's threat against e7. But again White
asks what checks he then would have and sees
that this time Qg7 would be mate. (Black's
queen was doing important defensive work on
f6.) So NxNc6 wins either way.
something to protect his king—e.g., with
f2xN, or QxNd4 (followed by Black’s recapture RxQ—after first playing Ng3-e2+ to
move his knight to safety with check). One
way or another White loses his queen.
When you experiment with initial knight
moves for Black, such as Ng3, the important
thing to remember is that for now you don’t
care if the knight easily can be taken, because
then you have QxQ. The question is just
whether White can afford to ignore the knight
move you are imagining. You answer this by
assuming that he does ignore it and then asking what follow-up move you would have.
Dg423: White to move
Dg422: Black to move
Dg422: More fun with knights. The kernel of
a discovery for Black should be obvious; his
knight on f5 masks an attack that his queen
otherwise would have against White’s queen,
which is loose. The f5 knight is on a light
square and White’s king is on a dark one, so
the knight can't give check; but it still might
be able to create enough trouble for White’s
king to produce the same result. Ask what sort
of pressure the knight can put on the White
king’s position. By moving to g3 the knight at
least cuts off the king’s only flight square: h1.
Does this matter? Yes, if Black has another
piece he can bring to bear on the king to
squash it in its cramped position. Black imagines White replying to Ng3 with QxQ and
asks what his next check would be; he sees he
would then have the game-ending move
Ne2#—another mate with the two knights. So
after Black's initial move Ng3 White can’t
afford to play QxQ after all. He has to do
Dg423: Notice the kernel of a discovery in the
White knight’s masking of his queen; see how
White’s two knights both are within a move
of bearing down on the king’s general position; observe that the king’s position is
cramped. The main structural difference lies
in the target: if the f4 knight moves, White
only has a bishop to attack with his unmasked
queen. But the bishop already is attacked once
and protected once, so it’s a perfect occasion
for a preliminary exchange: 1. RxB, and then
if Black recaptures QxR, the pattern is much
like the one in the previous frame. 2. Ng6 cuts
off the Black king’s only escape square, allowing White to threaten mate with Nd5-e7;
so after Ng6 Black can’t play QxQ. He has to
protect his king with a move like h7xN, and
then White is the one who plays QxQ.
In a sequence like this you have to ask
whether the attacked Black queen might have
some way to both remove itself from danger
and defuse the mating threat by perhaps tak-
ing one of the pieces involved in it. That
wasn’t a problem in the previous position
because the pieces contributing to the mate
threat had protection. But here Black could
reply to White’s 2. Ng6 with QxNd5, eliminating both the threat of QxQ and the mating
threat of Nd5-e7. Yet after noticing such a
capture consider (our mantra) the next check
you would be able to play. There would be
two here for White: Qxh7, which would not
work very well, and 2. Ng6-e7, which would
work very well indeed—not only because it
forks Black’s king and queen (always think
about forks when you move your knight), but
because after the compulsory 2. …Kh8 White
blows open the h-file and mates there with 3.
Qxh7, KxQ, 4. Rh1, Qh5, 5. RxQ#.
This sequence might look a little long, but
notice that White can foresee the whole thing
by simply asking what checks he would have
after each of Black’s evasive maneuvers:
there never are more than two for him to
worry about here, and eventually they lead to
mate. The trick is to remember all of your
potential checking resources—including the
rooks on your back rank, which can be moved
to the h-file in a hurry. We will look more
closely at this idea in the section on classic
mating patterns.
threatening move for the knight. From f3 it
can’t check Black’s king, but study the king’s
position: once more White’s bishop bears
down on it, attacking an adjacent square—the
characteristically weak f7 (it's "weak" because
only Black's king guards it). If White’s knight
can’t give check, can it at least attack that
square? Yes, with Nxe5, unmasking QxB.
Now assess White’s attack on f7 to see how
serious it is. White’s next move—it would
need to be a check, and there’s only one—is
Bxf7+. In principle the king has three flight
squares, but two of them (d7 and f7) are attacked, so Black’s only legal move will be
Ke7. What is White’s follow up? Notice that
now the king is severely boxed in; most of the
squares around it are attacked. Again the important thing is to look for the next check—
and to remember other pieces you can add to
complete the net. Here the knight on c3
moves to d5, and it's mate.
What this analysis means is that Black has to
respond defensively to 1. Nxe5, probably with
d6xN. This allows White QxB and the net
gain of a pawn.
Dg425: Black to move
Dg424: White to move
Dg424: White’s knight on f3 appears to be
pinned to his queen by Black’s bishop in familiar fashion. But we have seen that sometimes a pin of a piece against the queen can be
turned into a discovered attack by the queen;
this is a particular danger where, as here,
Black has left the bishop loose in his eagerness to impose the pin. We just need a very
Dg425: A minor variation. White has the familiar pin of a knight—here on f6—to Black's
queen. This time the pinning bishop isn’t
loose—yet; but we still ask whether the
knight, by moving out of the way, might be
able to create pressure on the enemy king.
Once more a bishop attacks the enemy fpawn. Can Black’s knight add pressure to that
square? Yes, with NxN: now two Black
pieces are attacking f2. Is it a mate threat?
Follow it out, looking for checks and asking
what comes next after each White reply. It
works like the previous problem: Black plays
Bf2+, White moves the king to e2, and then
Nc6-d4 is mate for Black.
The point of analyzing the mate threat, of
course, is just to determine that if Black starts
by playing NxN, White can’t afford to reply
BxQ. He has to play d3xN, ending the mate
threat but then losing a piece after White
takes the bishop with his queen. The initial
discovering move removes the bishop’s
guard, leaving it loose after all.
3.3.5. More on Mate Threats: Vertical and
Horizontal Patterns.
So instead Black fends off the mate threat and
loses his queen, which is loose, presently.
We might as well sketch Black's actual play
in reply to 1. Nxc6, which can get a bit complicated. Black's best move is Bxb2+. You
might expect White to reply KxB, but no: that
would allow Black to play Qf6+ next move,
using the priority of check to remove his
queen from danger. Instead White replies to
Bxb2 by simply moving his king to b1. Now
Black plays BxN to defuse the mate threat,
and White has the move he has been waiting
for: QxQ. Or instead of BxN, Black could
play his queen to a3; there it seems to be out
of danger, and it guards both mating squares:
a7 and e7. But then White simply goes ahead
with Ne7+, which requires Black to capture
the knight by playing QxN. Again, White now
has QxQ.
Dg426: White to move
Dg426: Find the kernel of a discovery for
White. His knight masks his queen on the efile; this formation of three pieces on a line
should be instinctively visible. White needs to
vacate the knight from e5 in a sufficiently
threatening manner to allow him to play QxQ
a move later, which likely means he needs the
knight to threaten Black’s king. The knight
can’t give check, but it can move into the
king’s vicinity; and the bishop on g3 is aimed
that way, too. Indeed, when the e5 knight
moves, it will discover an attack by the bishop
on both of the king’s flight squares. Nxc6 thus
puts tremendous pressure on the king’s position. It is just as effective a distraction as a
check would be, because if Black does anything to save his queen White plays Nxa7# on
his next turn. (He also threatens mate with
NxQ, or any other move of the knight to e7.)
Dg427: White to move
Dg427: The pattern we are considering should
be no less evident when the three pieces involved are arranged horizontally, as they are
here: rook-knight-rook on the fourth rank.
Another signal for White to see is that Black’s
rook is loose; it would make an easy target if
White could get his knight out of the way and
give check at the same time. He can’t, for
again his knight and the enemy king are on
squares of different colors. But it still pays to
study the king and its vulnerabilities. Black's
king has little room to move. All its flight
squares on the fourth rank are sealed off by
White’s king and pawns; so is g5. Indeed, the
only place it can go is g6. It follows that
White would mate if he could safely attack
the king’s current position and g6. A knight
can do that sort of thing—but from what
square? In theory there are two possibilities:
e7 and h4. The latter square is out of reach,
but by moving the knight to d5 White threatens Ne7#; the initial move to d5 therefore is
as threatening as a check. Black has to fend
off the mate threat. If he tries to create a flight
square for his king by moving his knight, then
of course White has RxR—the point all along.
This position resembles the mating threats we
have been considering lately because in either
case the unmasking knight doesn't check or
capture as it unveils the discovered attack;
rather, it moves into position to threaten a
crushing blow a move later.
Ah, but wait: we must consider whether Black
might somehow move his target to safety and
extinguish the mate threat. He can—sort of—
with 1. …Rc7, avoiding White's threat of RxR
and also guarding the mating square e7. But
this still sacrifices the exchange, as White
then has 2. NxR, NxN.
Dg429: Black to move
Dg428: White to move
Dg428: This position doesn't involve a mating
threat but it depends on a similar train of
thought. See the kernel of a discovery on the
third rank: the White rook, White knight, and
Black queen in a line should be suggestive.
What threat can the knight make as it evacuates e3? Black’s king is out of range—on this
move. But look for moves that would allow
the knight to give check a move later, and
consider whether that check might be of interest—if not as a mating threat, then as part of a
double attack. Black’s king and rook are
poised to be forked from h6. Ng4 thus threatens Nh6+. Black has the choice of replying to
Ng4 by (a) taking the knight with the h5
pawn, losing his queen to RxQ, and then taking White’s rook with the pawn that would
then be on g4; or (b) he can save the queen
and lose the exchange to the coming knight
fork. Either way White takes a decisive advantage.
Dg429: We always are alert for pieces on the
same line, and so have no trouble here seeing
the kernel of a discovery for Black on the fifth
rank. If his knight could make a substantial
enough threat, he could play QxQ a move
later. Since the knight can’t give check, think
about other threats it could make: is there a
square it can reach from which it would then
be able to give a check with interesting implications? Yes; with Nxe4 Black unmasks QxQ,
and also moves the knight into position to
take White’s rook with check on the next
move. And Nxe4 does more: it puts the knight
into the path of Black’s queen, creating the
kernel of a second discovery by Black on the
e-file; if White retreats his queen, Black thus
plays NxRd2+ and then QxRe1 after White
moves his king. To prevent all this, White
presumably will respond to Nxe4 with QxQ.
Black was ready to allow this because his
queen has protection from the bishop at g7,
but notice the importance of not recapturing
right away. Exhaust your checks first: after
White plays QxQ, Black picks up White’s
rook with NxR+; then, after White’s king
moves, there still is time for Black to play
BxQ or d6xQ (the priority of check).
3.3.6. Discovered Check with the Knight.
be reached the move after next. 1. Nc5+, Kf8;
2. NxQ wins the queen for the knight.
Now some examples of patterns that arise
when the knight discovers check, giving it
two moves with which to create havoc.
Dg432: White to move
Dg430: To the diagram probably is the simplest possible example. The kernel of the discovery should be obvious enough, as it consists of White’s only remaining pieces. If the
knight moves from f6, the bishop checks
Black’s king. This means the knight will have
two unfettered moves in a row. So look for
enemy pieces on the same color square as the
knight; be ready to move it in any direction.
The natural target is the queen if it can be
reached, and so it can: 1. Ne4, Kg8; 2. NxQ.
Dg432: The cluster on b3 and c4 is the kernel
of a discovered check; White will attack
Black's king with any move of his knight out
of the bishop's path. Since the knight is on a
light square, look for enemy pieces also on
light squares that might make good targets.
You thus find the Black rook on a8, the Black
bishop on b7, and the Black knight on g4. The
rook is the least attractive of these possibilities because it's guarded. As between Black’s
knight and bishop, the knight makes the better
target because White can pick up a pawn
along the way: 1. Nxe5+, 2. Kh8; and now
NxN.
Dg431: White to move
Dg433: Black to move
Dg431: The simple form again, this time running vertically. The kernel of the discovery
should be evident on the e-file. White sees
that the king is at the other end of it and thus
realizes that his knight will have a free move.
Black’s queen always is a favored target; here
it’s on a light square, as is the knight, so it can
Dg433: Black is threatened with the loss of a
rook on his back rank. Meanwhile he has an
offensive opening of his own at the other end
of the board: his knight masks the bishop on
c5; since the bishop would attack White’s
king if unmasked, the key question is what
damage the f2 knight might do while Black
fends off that check. Do you see how this offensive opportunity relates to the threat of
Dg430: White to move
RxRe8 that currently worries Black? The
strength of White’s threat depends on the coordination of his rooks on the d-file; that is
what prevents Black from being the one to
gain with RxR. Things would be different if
the connection between White's rooks were
disturbed—and as it happens, Black can cut
the rooks off from each other and discover
check at the same time with 1. …Nd3+, 2.
Kh1, RxR. Black wins a rook; the knight severs the line of protection to White's d8 rook—
and then the knight is protected against capture by the Black rook that moves onto d8.
knight to safety with Nf6 (rather than guarding it with d7-d5), producing the result shown
here; for this leaves the kernel of a discovery
in front of Black’s king. White’s knight now
can go on the attack with impunity. Black’s
queen is within reach via Nc6+; the queen is
lost to NxQ a move later, whether it stays
where it is or moves to block the check on the
e-file.
3.3.7. Discovered Checks with Preliminary
Exchanges.
The more obvious 1. …Ne4+ doesn't work.
White again replies 2. Kh1, so now Black can
play NxR, thinking he has won the exchange
after White recaptures; but White doesn't recapture right away. He instead executes that
ongoing threat of RxR+. The priority of check
means that he holds the initiative while Black
replies Bf8 (forced); and now White still has
the recapture BxN waiting for him at the near
end of the board.
Dg435: Black to move
Dg434: White to move
Dg434: This is the conclusion of a famous
trap in the Petroff defense. After the opening
1. e2-e4, e7-e5; 2. Nf3, Nf6; 3. Nxe5, Black
should not reply with the symmetrical Nxe4.
If he does, White plays Qe2—as happened
here (look at the Black knight on f6; imagine
it instead on e4, as it was a moment ago). The
move seemed to attack Black’s knight on e4,
but more importantly it put White’s queen
onto the same file as White’s knight and
Black’s king. The makings of a discovered
attack thus were in place, with Black’s own
knight on e4 the only impediment. Black
blundered away the game by then moving his
Dg435: Where does Black have the kernel of
a discovery? On the g-file, where his knight
masks his rook; friendly pieces next to each
other always require a close look. Next Black
looks for a target for the rook and sees
White’s rook on g2—with the king right behind it. Nf5, threatening the queen to make
time for RxR a move later, makes no sense;
the rook is guarded, and anyway White can
end the threat with RxR+. But when the enemy king is close to your target the natural
thought is to try for a substitution, even if it
entails a temporary sacrifice. So Black starts
with 1. QxR+, and, after the recapture KxQ,
now has the makings of a discovered check.
He only needs a target that his knight can
reach in two moves, and of course he finds it
in the queen on h6.
queen (whether the queen stays where it is or
interposes on d3).
Dg436: White to move
Okay, but what if White instead replies to
Rxc2 with QxR? Answer this question in
standard fashion: examine every check you
would be able to give in return. Black's only
check here would be Qe1. No moves the
White king could make would save it; White
would have to interpose his queen, and
whether he does it on c1 or d1, Black mates:
QxQ#.
Dg436: The same idea in a different visual
setting. White's knight on f4 masks his queen,
which is aimed at the Black knight on h6.
Black's knight is protected and thus is an unsuitable target, but since it's next to Black's
king a substitution is possible: RxN+, inviting
the recapture KxR. Now White is ready to
play Nxd5+, and—after the king moves—
NxQ. Notice that 2. Ng6+ also would work
for White, since the knight would have protection on g6 from the rook on g1. But then
White wins one less pawn.
Dg438: Black to move
Dg437: Black to move
Dg437: Black’s knight masks his queen. The
queen doesn't yet have a good target, but it's
aimed at the pawn in front of Black’s king; so
Black might have a discovered check if the
position were jiggered slightly. Consider what
other pieces on both sides factor into the position. Black’s rook also attacks the c2 pawn.
White’s queen is nearby, at d1. An idea
comes into view: Black's knight could attack
the queen with Nf2, and unmask a discovered
check at the same time, if the pawn on c2
were removed; and perhaps the rook can perform the removal with Rxc2. If White responds with KxR, then Nf2 indeed wins the
Dg438: One reason to look habitually for kernels of discoveries is that they can help organize the rest of your tactical thinking. Where
are the kernels here? Black’s g6 knight masks
his rook on g8, and his knight on c6 masks his
bishop on b7. Both masked pieces are aimed
in the general direction of White’s king. The
more intriguing kernel is the bishop behind
the knight on c6, because that knight can go
after White’s queen with Nb4. If the bishop
were to give check when the knight jumped
out of the way, NxQ could follow. But all this
would first require substituting White’s king
for his bishop on g2. Can it be done?
Work backwards: Black would like to take the
bishop with another piece, requiring White to
recapture with his king. The only Black piece
now aimed at the bishop is the rook on g8. Its
path is blocked by the Black knight on g6 and
the White pawn on g3. Can those obstacles be
removed at the same time? Yes, if the knight
captures something the pawn protects. So
Black plays 1. …Nxh4, inviting White to reply 2. g3xN. Now the position is easy: 2.
…RxB+, 3. KxR, Nb4+ (dis ch); and Black
takes White’s queen on the next move—and
then forks White’s rooks to boot.
3.3.8. Discovered Mate Threats.
As with many tactical sequences, this one can
be foiled early; White simply declines to recapture when Black plays Nxh4, accepting the
loss of the pawn rather than heading down the
road toward material catastrophe. So against
an alert opponent the value of seeing this sequence is not that you then are able to play
the entire thing; it's that perceiving the threat
of it allows you to make smaller gains because you know your opponent can't afford to
retaliate.
Dg440: White to move
Dg439: White to move
Dg439: Last, a sequence that involves clearing a path to create a discovered check. Start
by spotting the kernel of a discovery for
White on the g-file: anytime you have a rook
with a friendly piece in front of it, take notice.
Here the idea is especially appealing because
Black’s king is on the same file. Ask what
stands between White and a discovered check.
Answer: only the g6 pawn. How do you force
a pawn to move? By capturing something it
protects. The g6 pawn protects the queen, so
White plays QxQ; after Black replies g6xQ,
the path on the g-file is clear for the discovered check—indeed, the double check—
Ne6++. After Black moves his king (the only
possible reply to a double check), White has
NxR. Black recaptures and White has won the
exchange.
Dg440: Now let's see how it can look when a
knight discovery involves a threat of mate. In
this case the discovery isn't White's best
move, but let's find it anyway. White's knight
masks his queen: the kernel of a discovery,
even if it's a little hard to notice because the
queen appears to have no target on f8. But
you always want to be aware of the enemy
king and its constraints; it's especially important when you have a piece aimed at the back
rank. What happens if White moves the
knight and then plays Qf8 a move later? It’s
mate. So White has a perfect target for the
queen after all in the f8 square. He can play
Nc6; and after Black fends off the threat of
Qf8#, White has NxQ.
So what is White's best move? Qe5+; Black
has to reply with f7-f6, which then results in
Qxf6#.
Dg441: White to move
Dg441: White has the nut of a discovery on
the long diagonal leading to h8. His queen has
no piece to attack if the knight moves, but
since it’s aimed in the general vicinity of the
king you consider squares the unmasked
queen could attack, not just pieces. Look for
any checks the queen would be able to give
and you find Qh8—and see that would be
mate. Black would no more be free to ignore
that threat than he would be to ignore a discovered check. The knight therefore will have
an unfettered move to make after it vacates
the queen’s path to h8, and can use it to go
after Black’s queen: Nd5, and then—after
Black takes measures to avoid being mated—
NxQ.
Dg442: White to move
Dg442: Here's a harder one. Find the kernel of
the discovery: White’s knight masks his
queen on the seventh rank. If the knight
moves, the queen again has no piece it can
target—just a pawn, and a protected one at
that. But once more you examine the Black
king and find that the queen would have a
great square to attack: Qg7 nearly would be
mate; only the Black knight on e6 would prevent it. Now the important thing when your
pieces close in on the king like this is not to
think about the two halves of the discovery in
isolation. Think instead about how the two
parties to it—here the knight and queen—can
help each other. If White plays the discovery
1. Ng5, he threatens NxQ. More significantly,
though, the knight also attacks another square
next to Black’s king, thus creating the new
mating threat Qh7#. Against this idea Black’s
knight is no help. He is forced to play 1.
...Rxf6, as this erases the immediate mate
threat on g7 (by removing the protection
White's queen would have there) and also
gives the king a flight square (f8) if White
plays Qxh7.
At this point it might seem natural for White
to complete the sequence by playing 2. NxQ,
but that would be a mistake. Black then would
have RxR+ (easy to overlook!), leaving White
still with a winning advantage but not an immediate win. Your first order of business
when you have pieces bearing down on the
king is to look for mate. While Black’s move
Rxf6 ends the threat of 2. Qxh7#, the move 2.
Qxh7+ still takes control of the Black king’s
fate and keeps the initiative, comfortably
postponing the capture NxQ through the priority of check. Black’s king is forced over to
f8. White again has a chance to play NxQ, but
once more he waits, preferring instead to
bring another piece into the mix with RxR+.
Black’s king is forced to e8. Now White plays
NxQ, having used checks to keep that capture
available for two moves. Black’s knight, his
last remaining piece, has no safe place to go,
and will be lost next move—leaving White
with a queen, rook, and knight and Black with
no pieces at all. Mate follows shortly.
3.3.9. Discovered Check Leading to Mate.
Again we consider how an idea seen in prior
chapters can apply to the knight: sometimes
the piece that unmasks a discovered check
can, instead of hunting for material, add more
to the pressure on the king or otherwise take
part in the creation of a mating net.
Dg443: Black to move
Dg443: The position to the left shows how it's
done in simplest form. See the kernel of the
discovery for Black on the e-file; see that the
piece to be unmasked, the queen, is aimed at
White’s king. Should the knight go after material, for example by jumping to g4 and then
taking the White bishop on f6 on the next
move? No, Black should play the knight to f3,
delivering checkmate. From f3 the knight
adds a second check, which means the king
has to move; and the knight seals off d2, the
king’s only flight square.
Notice that from the outset Black is threatened with BxQ. This is another reason why a
simple discovered check like Ng4 would fail;
White would just take Black’s queen. The
only discovered checks that will work here
are double checks, because they require your
opponent to move his king.
flight squares should suggest an attack by the
knight, since it can hit them both at once—
i.e., with Na6#, finishing the game since
White’s rook cuts off the whole d-file.
This is another sequence where Black’s threat
not only is decisive offensively but also does
important defensive work by holding the initiative. If it were Black’s turn to play he, too,
would have a forced mate: 1. …Qh2+; 2. Kf1,
Qh1+; 3. BxQ, RxB#. One way to defend
against a threat like that is to launch an offensive sequence of your own, giving your opponent no chance to get in his attack.
Dg445: White to move
Dg444: White to move
Dg444: The cluster of White’s bishop and
knight on e4 and f3 should jump out at you as
the possible basis of a discovery (generally
speaking, any friendly piece lined up with a
knight should get you thinking this way). The
bishop has no target yet in place, but since it’s
aimed toward the enemy king’s corner,
thoughts of a discovered check come to mind.
The king would need to be drawn over a
square onto the long diagonal. A simple if
costly way to do this is by planting the queen
on the square where you want the king to go,
forcing it to capture there; thus Qb7+ causes
KxQ. Experiment with what might come next:
Nc5, a double check, forcing the king to move
and so keeping all of your pieces safe. What
would Black do? The a8 and b7 squares are
off limits to his king (imagine a line through
that diagonal), and so is a6 (thanks to your
knight). So Black would have to play the king
to c7 or b8. Now consider White’s next
checks in either case. The pattern of those two
Dg445: Our current logic continues. Everything starts by spotting the kernel of the discovery. Here White’s knight on h4 masks his
rook. (When the h-file is open and the enemy
king has castled on that side, be alert to the
relationships between any pieces you have on
that line or able to reach it.) A good first question is whether the piece to be unmasked has a
promising target—and, if not, whether one
can be created. In this case there's nothing for
the rook to take at the other end of the h-file,
but the king is close by; might it be moved
over? A natural way to accomplish this is
with a check, and especially by a check from
a piece moved onto the h-file that the king
will be obliged to capture there. So consider
Qh7, which requires Black to play KxQ. It’s
an expensive sacrifice, but since the enemy
king is in play it might be worthwhile. Now
Ng6+ unmasks check by the rook; what
would Black do then? There would be only
one legal move: Kg8. Look for a final check
and you come to Rh8#, with the rook receiving cover from the knight.
Dg446: White to move
Dg447: Black to move
Dg446: The key feature of this position is the
kernel of a discovery for White on the e-file
leading towards Black’s king. At the moment
the bishop on e7 is in the way; it makes a poor
target in itself, because it’s guarded and less
valuable than the rook that would be able to
capture it. But the position would get more
interesting (because it would involve discovered check) if the bishop could be captured
and replaced by the king—and likewise if the
bishop could be drawn away from the e-file.
White considers whatever checks he can give
and finds that 1. Qf8+ has the desired effect,
forcing Black to play BxQ to protect his king.
Now the discovery is arranged, but to what
end? It had better be good, since a queen sacrifice was needed to get there. Black’s king is
in the type of cramped position you should
associate with mating possibilities, so think
about using both pieces in the discovery to go
after it. 2. Ng7++ is the answer, inflicting a
double check that requires the king to move to
d8. Look for the next check. Here it’s Re8—
mate. (Notice that 2. Nc7++ works as well as
2. Ng7++; again Black’s king is forced to d8,
and again White mates with Re8. It might
seem that if White plays Nxc7 Black could
then escape a move later with KxN, but
White’s bishop protects the knight from h2.)
Dg447: Black has the kernel of a discovery
leading toward White’s king on h3-g2. He
could use his knight to go hunting for Black’s
queen, but the idea is complicated by the attack underway against his own queen; and in
any event, when the king’s position is so
cramped it makes sense to focus on the possibility of mate. If Black's knight moves,
White’s only option is to move his king to e1
or g1. Imagine the knight out of the way—
moved to h4—and consider how it could go
after the king on either of those flight squares.
The details differ, but at a higher level of generality our current pattern thus repeats: queen
sacrifice; check; checkmate.
(a) If White plays Ke1, what checks does
Black then have? QxB, which doesn’t work;
and NxN, which is mate because the bishop
on e2 is pinned.
(b) If White instead plays Kg1, NxN no
longer works because BxN results, the bishop
not being subject to a pin. But this time the
queen check does work: Qg4# ends the game.
This is a good study in the value of carefully
examining the checks you can give at every
turn. After Black's first move the White king
has two places to go. Either way, Black has
two checks; and either way, one of them is
ineffectual while the other is mate.
Dg448: White’s knight on e4 masks the paths
of his rook and queen (it's an example of
something nice that can happen with a knight
in the center); the queen is the more important
piece, of course, because it has the king as a
target once the knight moves. How to exploit
this? If the knight goes to f6, then of course
Black takes it out and avoids the check with
KxN. But don't give up.
Dg449: White to move
Dg448: White to move
The king’s position doesn't look as constrained here as it did in the previous position,
but its mobility still is quite limited because
White has several pieces bearing down on it.
If there is a mating net to be created, every
move in it almost certainly will be a check; so
imagine going through with 1. Nf6+, KxN,
and then examine any checks White would
have and their consequences.
The most useful of those follow-up checks
would be 2. Nh5+. As you consider Black’s
reply you might imagine a dark line leading
through the squares on the White queen’s
diagonal and another line all the way down
the e-file, since those squares all are off limits
to the king. And g7 is off limits, too, because
it’s attacked by the knight. In fact the king’s
only flight square would be f7. Now look for
White’s next check, keeping in mind that
every square adjacent to Black's king is under
attack except g8. Qh7# seals off that square
and attacks the king as well, leaving it nowhere to go and ending the game.
The position is a good illustration of how a
king can be tightly constrained even when it
has lots of empty squares nearby—if those
squares are under attack. It takes some practice to get the hang of seeing this; it's worth a
little time.
Dg449: A horizontal study. White has the
kernel of a discovered attack on the seventh
rank; his rook is aimed toward Black’s king.
Even if the path of the discovery is blocked
for now by the bishop on g7, this configuration is a valuable asset and can guide the
thought experiments that follow. Consider
White's checks and their consequences. Qh6+
is most interesting, as the queen is protected;
it forces either BxQ or Kg8. What next?
(a) If Black chooses BxQ, it clears the way
for the discovered check we had hoped might
materialize: now Ng5++ forces the king to h8
(notice that White’s bishop on b3 also participates). And then Rh7 is mate.
(b) If Black plays 1. …Kg8 instead of 1.
…BxQ, then 2. Qh8+, BxQ; 3. Nh6# likewise
is mate via discovery—this time using the
bishop on b3, which the knight also was
masking. The queen sacrifice on h8 serves to
leave that square blocked, further constraining
Black's king.
The trick to the position is seeing that the
knight masks pieces in two directions, both
aimed in the enemy king's vicinity. This creates multiple chances for game-ending discovered checks once Black's king is pushed
around a bit. More generally it's a valuable
study in the importance of thinking beyond
the two obvious pieces in a discovery; White
finally uses four pieces to wrap this position
up.
3.3.10. Building the Kernel: Diagonal Patterns.
The usual position in this chapter starts with
the kernel of a discovery in place at the outset. Perhaps the target needed to be created or
improved, or maybe a good threat needed to
be found or made for the unmasking knight;
but the idea was in place from the start and
easily triggered trains of thought about how it
might be made to work. We now consider
some cases where the kernel is not in place at
the start—where it first must be built with an
initial move that creates the familiar masking
pattern while also forcing a reply by your opponent. The forced move itself often adds one
of the necessary elements for a discovered
attack, usually by moving a target into place.
Then follows the unmasking move that attacks two points in the enemy camp at once,
requiring one of them to be forfeited. Visually
your task is to become alert to moves that put
one of your pieces (in these cases a knight)
into the path of another, and then to go
through the familiar process of imagining
how the discovery might be perfected.
fectly safe, as opposed to Nf6+)—and then he
has QxQ after Black moves the king from h7.
The trick to the position, of course, lies in
seeing the kernel of a discovery when it isn’t
on the board in front of you but will be created by a move or series of them that you are
contemplating. The prospect of a discovered
attack would not occur to you in the original
position; it only comes to mind once you experiment with Qc8+ and observe what it does.
When you think of a move that puts one of
your pieces in line with another, pause to consider the tactical side-effects for you—or for
your opponent.
Notice, by the way, an amusing mating possibility if Black blunders into it: 1. Qc8+, Kh7;
2. Nf8+, Kg8; 3. QxQ, KxN; 4. Qc8#—a back
rank mate made possible by Black’s silliness
in allowing his king to get trapped behind his
pawns and rook with no defender.
Dg451: White to move
Dg450: White to move
Dg450: In the position on the diagram, assume Black just made a capture with his
knight on b5; now the natural tendency for
White would be to play QxN. Don’t do it.
Always examine your checks to see where, if
anyplace, they lead. Here White has the interesting Qc8+. You see that this forces Black’s
king to h7, and that White then runs out of
good ways to hunt the king down. The crucial
thing is not to give up then, and instead to
back up and see what patterns would be in
place. White would have formed the kernel of
a discovery: his knight now masks his queen’s
path toward Black’s queen on g4. White can
unmask the attack with check—Nf8+ (per-
Dg451: White has no good discoveries to unveil at the moment; his bishop on g2 is behind
his knight, but the bishop lacks a good target.
So White experiments with other moves and
finds that two—Nc5 and Nd6—are of special
interest: they both move the knight into the
path of White’s other bishop on a3, creating
the kernel of a discovery. Examine such
moves carefully to see whether they might
also force an enemy piece into place as a target of one of the pieces in the kernel. Nc5 is
unattractive because it doesn’t force anything
(it’s also bad because it lets Black uncramp
his position by exchanging knights). But Nd6
is another matter; it attacks Black’s rook.
Taking the knight with QxN is out for Black
because the knight has protection; the rook
must be moved instead. But where? It has
three possible squares: g8 (leading to the
smothered mate Nf7#), f8, and e7. The key
point about either of the last two possibilities
is that they move the rook onto the same diagonal as White’s bishop on a3, creating a
target for it once it is unmasked. The knight
then on d6 just needs a violent move to make
as it unmasks the bishop. Giving check on f7
wouldn’t work because it enables the rook to
both extinguish the threat and take itself out
of trouble. The correct move is NxBc8. If
Black recaptures, BxR wins the exchange for
White on the next move; if Black doesn’t recapture and spends his move saving the rook,
White has won a piece.
As this case shows, moves that create the kernel of a discovery are most interesting when
they make a side threat against the enemy at
the same time; for then he has to spend a
move dealing with the threat rather than dealing with the discovered attack you've just
constructed.
Dg452: Black to move
Dg452: Find the discovery for Black. The
most promising kernel is on the long diagonal
where his knight masks his queen, but it's no
good because the rook on d4 is protected. So
Black plays with other moves; he looks for
any checks he might give and finds Nf3, forking White’s king and rook. If White defends
with g2xNf3, he opens a line to his king on
the g-file—an interesting result. Consider
whether the move gives Black any new
checks and you find Qg6+. It forces White's
king onto h1—and (the key point to see)
slides Black's queen onto line with its knight
and White’s queen, creating a new kernel of a
discovery. With the king moved to h1, the
knight on e4 can give check, and unmask a
discovery, with Ng3. After White takes
Black’s knight, as he must, Black plays QxQ.
White doesn’t have to defend against the initial knight check with 2. g2xN, of course. He
can play 2. Kh1. Then Black wins the exchange and a pawn with 2. …NxR; 3.
e3xNd4, Qxd4.
Dg453: White to move
Dg453: It's important to be alert to mate
threats. One way to find them is by looking at
any pieces already attacking squares adjacent
to the king. Here White’s knight attacks g7,
and the square is protected only by Black’s
king. If White were to add an attack on that
square by his queen, he would threaten mate,
so naturally he looks at Qg4. The move not
only creates a mate threat but also moves the
queen behind the knight on f5, creating the
kernel of a discovery—the two queens with a
knight between them. How would Black respond to the mate threat? He can play g7-g6;
but even so, Nh6, while not threatening mate,
then gives check and unmasks the capture
QxQ. Again we see that the key is to create
the kernel while also creating a side threat
that busies your opponent.
Dg454: White to move
Dg455: White to move
Dg454: No doubt you see the kernel of a discovery: White’s knight masks his bishop on
the h1-a8 diagonal. But not much can be done
with it; the more fruitful thing to notice is that
White has a bishop bearing down on the king
on the other long diagonal—and that White
can create the kernel of another discovery,
and also give check, by moving his knight to
f6. That move both masks the bishop with the
knight and forces Black’s king over to h8,
putting a target into place for a discovered
check. Now the knight will have two unfettered moves, so it heads toward Black’s queen
via his rook: NxR, followed next move (after
Black avoids the check from White’s bishop)
by NxQ.
Dg455: When pieces are collected on a line,
as they are on the b-file here, it is natural to
wonder how you might take advantage of the
arrangement. Or you might simply consider
every check White can make and see Rb6+.
Either way the point to see is that Rb6+ creates the kernel of a discovery, with White’s
knight suddenly all that stands between his
rook and Black’s queen. Usually—and here—
a move that so creates the kernel of a discovery is really interesting only if it also helps
create the other elements of a discovered attack by forcing targets into place. In this case
Rb6 also forces the king to find a new square,
and its choices are limited to a8 and c8.
Whichever move Black makes, the king ends
up on the same color square as White’s knight
and is checked on the next move with Nc7+
or Na7+. After the king avoids the check,
White takes Black’s queen.
The only fly in the ointment is that after
White plays Nf6+ at the outset, Black can end
the threat with NxN. How to remedy this?
With a preliminary exchange: 1. QxN, BxQ,
and now play continues as described above
with Black’s defender of f6 eliminated. The
queen sacrifice is costly, of course, but it pays
off soon enough.
Notice the style of thought: take note of
moves that put one of your pieces onto a line
with another that can unmask it; consider
whether any of those moves also force a reply
from the other side, and especially whether
they force a target into place.
3.3.11.Building the Kernel: Vertical and
Horizontal Patterns.
Dg456: White to move
Dg456: White has lots of ways to give check
with his queen, so inquire into the consequences of each. The most interesting is Qe6.
Why? Because it moves the queen behind
White’s knight and Black’s queen on the efile; it thus puts three pieces on a line in the
familiar formation for a discovered attack.
Again, moves that so create the kernel of a
discovery usually need to force other changes
on the board that keep the enemy busy and
that may also create the remaining elements
of the tactic. Here Qe6+ not only creates the
kernel of a discovery but also gives check,
forcing the king onto either h5 or h7. Either
way, with Nf6+ White’s knight will give
check and unmask QxQ.
Dg457: Black to move
Dg457: Black’s knight masks his bishop, but
the bishop lacks a good target if the knight
gets out of the way. So think about other
things to do with the knight. See how it can
jump into the path of the rook on the e-file,
creating the kernel of a discovery. It appears
that the rook would have no target, but remember to ask whether the knight’s move
might force useful adjustments by the enemy.
What threat would Ne3 make? It would fork
White’s rook and bishop. White would want
to move the rook out of the way, but if he
removes it from the first rank he leaves the
bishop loose. To protect both pieces he therefore has to play Re1—and this puts his rook
in line to be taken by the the discovered attack
Nc4+. Black wins the exchange.
Pawn Discoveries.
3.4.1. Introduction; Simple Cases.
Pawns can only move forward, so the patterns
they create when discovering attacks take two
forms. First, they can unmask diagonal attacks by bishops and queens, and horizontal
attacks by rooks and queens, as they move up
the board; this makes it important to notice
anytime a pawn is on the same diagonal as a
friendly bishop or queen. Second, and interestingly, by making a capture and thus moving diagonally a pawn can unmask a vertical
attack along a file by a rook or queen. This
means you want to notice anytime you have a
pawn in front of a rook or queen on the same
file—not an uncommon state of affairs—and
to think about whether the pawn can make a
capture (or whether a capturing opportunity
can be created) so that it unleashes a discovered attack.
We won’t be distinguishing very carefully in
this chapter between ordinary discovered attacks and discovered checks, because discovered checks comprise such a large part of the
universe of all pawn discoveries. It's very
useful to have a check at one of the two ends
of a discovered attack; and since pawns rarely
are in a position to check the enemy king
themselves, the job of giving check very often
becomes a task for the other, unmasked piece.
Dg458: Black to move
Dg457: Begin with the example to the left,
where it's Black's turn to play. Perhaps the
most common form of pawn discovery is this
pattern: a discovered check that arises when
you have a bishop or queen aimed through the
middle of the board at the enemy king, and
with one of your pawns blocking the way. If
the pawn can move forward with a threat, the
results can be crushing. Here Black has d4-d3,
forcing White either to move his king and
lose his queen to d3xQ, or (the better move)
to sacrifice the queen by moving it to f2, allowing it to be taken there, and then recapturing with the rook.
Dg459: The pawn discovery in horizontal
form. Here the eye-catching pattern again is
the alignment of the two queens, this time on
the same rank. If White’s pawn on e5 moves
forward, the queens are exposed to each
other; but of course for this to work the pawn
needs a big threat of its own. Hence e5-e6+,
and then QxQ next move.
Dg460: White to move
Dg458: Black to move
Dg458: Here is a true discovered attack (not a
discovered check) by a pawn. The most likely
tip-off to the idea is the presence of the two
queens on the same line—here, a diagonal. (It
pays to be sensitive to alignments of all sorts.)
If the pawn between them can vacate the diagonal and give check at the same time, Black
can play QxQ a move later. So f4-f3+ wins.
It's very simple. You might also have noticed
this, of course, by just considering every possible check and its consequences—the lines it
opens, etc. It takes some time to internalize
the idea that a pawn on the same diagonal as a
bishop or queen is such a powerful tactical
weapon.
Dg459: White to move
Dg460: A pawn usually will not be in a position to give check, but it may not need to be
in order to make a significant threat. The
power of a pawn lies in its expendability.
Here White has the kernel of a discovery on
d4 and e3, where his bishop is masked by a
pawn. The bishop has a loose knight as a potential target; after 1. d4-d5, Black retreats his
queen to e7 and White then wins a piece with
BxN.
Since the target of the attack—the knight—
can’t strike back at the bishop attacking it, the
threat the pawn makes need not be enormous.
Almost any threat against a piece would do, in
other words; it wouldn’t need to be against
the queen or a loose piece. The key to this
idea in this position just is noticing it. This
can be done by experimenting routinely with
possible pawn advances, or by habitually
looking at a piece like the bishop on e3 and
following its potential path through any
pieces in its way that might be moved, or by
focusing on loose enemy pieces like the
knight on b6.
By the way, notice that Black almost can win
the exchange here. Suppose he replies to d2d4 with Qg6. Then after White plays d4xB,
Black still has the pawn on g2 pinned. He
plays Bh3, threatening to mate with Qxg2. To
stop this, White can play g2-g3—but then
Black wins the exchange with BxR. What
prevents this is White’s queen on d1, which
he can move to f3 instead of playing g2-g3.
It's a pattern worth knowing.
Dg461: White to move
Dg461: Familiar idea, different direction. A
fianchettoed bishop on b2 or g2 (or the
equivalent squares on Black's side of the
board) often is easy to mask and unmask with
an advancing pawn; here, with a pawn on c3
in front of White’s b2 bishop, White has tremendous potential energy on the long diagonal, and Black plays there at his peril. In this
simple position both parties to the discovery
have open lines to good targets: c3-c4 unmasks BxQ and attacks—and wins—Black’s
bishop on d5.
3.4.2. A Step Up in Complexity.
Dg463: White to move
Dg462: White to move
Dg462: A pawn can unmask an attack even
when starting from its original position. Notice that at the start of a game each side already has the kernel of a pawn discovery in
place: the pawns on d2/d7 and e2/e7 mask the
bishops behind them (the queen is poised to
be unveiled, too, but set it aside for now). If
Black puts a piece near the middle of the
board and then leaves another on one of the
bishop’s diagonals, he may be asking for
trouble. Here White can unmask an attack on
Black’s queen by his bishop with d2-d4, also
attacking and winning Black’s bishop after
the queen moves.
Dg463: The forward progress of White’s rook
on d1 appears to be blocked by the pawn on
d4; a better way to think of the position, however, is that the rook merely is masked. The
difference might not matter if the pawn had
nowhere to go but straight ahead, but in this
case it can make a capture—and in the process it will change files, thus unmasking whatever attack may lie behind it. Thus d4xc5 attacks Black’s queen and also discovers an
attack on Black’s rook, which previously had
been attacked once and defended twice. You
still don't have enough power to take the piece
down, but you could change that by first using
your rook to get rid of the knight on f6.
All this is the beginning of the idea, not the
end of it. Since neither move you are planning
would give check, you have to ask whether
Black might reply with a check of his own.
He could: Black plays 1. ...RxR+ and the
threat is over. So now consider starting with a
substitution: QxR+; the thought would be that
if Black replies with KxQ, his king ends up
on the d-file and d4xc5 becomes a discovered
check. But this time there is another problem.
Black need not respond to 1. QxR with KxQ;
he can play NxQ instead.
These obstacles, too, are no reason to give up.
They simply focus your inquiry and lengthen
the sequence you are planning. You see that
the knight on f6 obstructs your idea, which
you knew anyway; so you take it out first: 1.
RxN, g7xR. Then comes 2. QxR, KxQ, setting up a check for your next move: d4xc5+,
and White wins a piece (he gave up a queen
and a rook to win a queen, a rook, and a
knight).
Dg464: Black to move
Dg464: Sometimes the chance to play a pawn
discovery can pop up in the middle of a
forced sequence. Black has little to work with
here, but he can give a safe check with Qh5,
so he considers White’s response and sees
that it is tightly forced: Kg1. The other interesting thing about Qh5 is that if you examine
the queen’s new lines you see that it is aimed
at the rook—the loose rook—on d1, with only
a Black pawn between them. Once White
moves his king the pawn can step forward to
f2 with check; White escapes with Kxf2, but
then Black has QxR. You might also have
seen this by starting with the loose rook on d1
and examining whether your queen somehow
can attack the rook and White’s king at the
same time. Qh5+ almost does it, at least aiming the queen at both pieces. You observe that
your own pawn is in the way; you see that it
can’t be removed in advance; and then you
play with the move order and see that the
pawn that seems to block the fork actually is
the key to creating a discovered attack.
Dg465: White to move
Dg465: White has a check that requies inspection in Qh4. Notice its attractive properties: it
plants the queen flush against Black’s king,
but with protection; and (the new point) it
aims White’s queen at Black’s queen, but
with a White pawn between them—the kernel
of a discovery. Black’s reply, Kf5, is forced.
Now White plays the discovered attack g3g4+. Black moves his king again. White plays
QxQ next move.
It's common enough for checking moves like
Qh4 to create potential discovered attacks
even if that possibility had nothing to do with
your initial interest in the move. The important thing is to see the kernel of a discovery
every time it is formed, even inadvertently. So
when you imagine moving a piece for the
sake of giving a check or for any reason, pay
careful attention to the new lines it occupies
and any possible discoveries you may be creating (or walking into) there. The practical
cues are any pieces already on the lines running from the square you are planning to occupy.
Dg466: Black to move
Dg466: It’s clear how Black should begin
thinking: with checks like Qf1 or Qe1. Either
move forces White to play Kb2 or (if Black
starts with Qf1) Kd2. But then what should
Black do? You will see nothing more if you
confine your attention to follow-ups with your
queen. The key to the position is to notice the
kernel of a discovery that exists from the beginning (and which is kept intact by Black's
Qf1)—the two queens with a Black pawn
between them. Or you might see the solution
by simply asking what check Black can give
after White has moved his king and remembering to include pawn moves in your thinking. The point either way is that if Black starts
with 1. …Qf1, he can follow it with the pawn
discovery c4-c3+, permitting him to play QxQ
next move.
Dg467: White to move
3.4.3. Arranging Pawn Discoveries on Diagonals.
Dg467: What are the critical visual facts of
the position to the left? They are, first, that
White’s pawn masks his bishop (the formation on b2 and c3 should strike you right
away); and, second, that White’s bishop and
queen both are aimed at the square in front of
Black’s king. Since White’s pawn can attack
Black’s queen with c3-c4, the important question becomes the target at the other end—on
g7. If White plays c3-c4 now, he also threatens mate with QxN. Sometimes a mate threat
is as good as a check, but not always, and not
here; the chief difference between them is that
a mate threat gives the enemy a wider choice
of replies. If he can inflict a check of his
own—especially with his threatened piece—
he may be able to put out the fire without doing anything about his king. That is the trouble in this case: after c3-c4, Black has the
check Qd1. Now White is the one whose
move is forced. He must play his king to the
second rank. And then comes the next check:
Qd2+, a double attack on White’s king and
his loose bishop. White can avoid the loss of
the bishop with Qf2, but this wasn’t exactly
what he had in mind at the outset.
Now let's consider pawn discoveries that require preliminary exchanges. Our focus will
be on a single motif: creating a discovered
attack in which the pawn unmasks a diagonal
attack by a bishop or queen in the direction of
the enemy king. Afterwards we will look at a
few pawn discoveries that follow other patterns.
Meanwhile, of course, there is a better alternative to all this. Instead of playing c3-c4
first, White starts with the preliminary exchange 1. QxN, KxQ. Now c3-c4+ is a discovered check, giving Black no chance to
take the offensive and winning back the queen
for White (with the gain of a piece) a move
later.
1. …Qe1, by the way, not only doesn’t work
but results in mate for White. Notice that
White is close to mating already with his rook
and queen; he does so as soon as Black runs
out of checks that hold the initiative. Thus 1.
...Qe1; 2. Kb2, c4-c3+; 3. Kb3, and Black has
no way to stop White from playing Ra7+. If
Black replies by moving his king to d8, White
mates with Qd7 or Qb8; if Black instead
moves his king to c8, White mates with Qe8.
Studying the operation of White’s queen and
rook in this position is highly worthwhile, as
their ability to mate by trapping the king in
this way (sealing off two ranks) comes in
handy. What also makes it work, of course, is
the Black king’s inability to escape toward the
center with Kd6.
sic fashion. The obvious hitch is that the path
isn’t clear; Black’s e6 pawn is in the way. So
go to work to eliminate the obstacle. We customarily remove bothersome pawns by capturing whatever they protect. Here the e6
pawn protects the knight on d5, so Black captures it with RxN, inviting e6xR. Now the
discovered check e5-e6 is easy, winning the
queen with e6xQ or (if the queen moves to f6)
NxQ.
Dg468: White to move
Dg468: White's rook on h3 is threatened with
capture by Black's g-pawn. But White has the
makings of a threat of his own: his pawn on
e5 masks his bishop. White’s bishop is aimed
toward the Black king's territory, the king’s
pawn cover is blown, and the e5 pawn can
attack Black's queen with a step forward. That
move—e5-e6—threatens mate (Rh8), but
again the drawback of a mate threat is that
your opponent has a wider choice of replies
than he does when you give check. Here he
would look for a move that defuses the threat
and moves the queen out of danger—and
would find it with the simple Qxe6, devouring
the pawn and giving his king a flight square
on f7. No, the better course is to first draw the
king into position to be checked by playing
Rh8+. Black must play KxR or Kg7; in either
case the king is moved onto the long diagonal.
Now comes e5-e6+. Black plays Qg7, offering
to exchange his queen for White’s bishop to
avoid mate. You accept the offer.
Dg469: White to move
Dg469: Observe White's queen behind the e5
pawn; the formation invites a search for a
discovered check. Think of the pawn moving
forward and attacking Black’s queen in clas-
Dg470: Black to move
Dg470: Black’s bishop and d4 pawn are on
the same diagonal, signaling a potential discovery. (Notice the recurring visual pattern: a
pawn in the center and a bishop aimed
through it and toward the enemy king.) The
pawn can step out of the way and attack
White’s queen at the same time. The problem
is becoming familiar in structure: the pawn on
f2 would block the bishop, preventing it from
giving check. So remove the pawn by taking
something it protects—the g3 pawn, which
Black can capture with his rook. But there is a
flaw: consider whether the recapture you want
would be compulsory or could be made by a
different piece; be aware of how many times
any piece you might take is protected. Here
Rxg3 is met by White not with f2xR but with
NxR. So what to do? Just push the plan back a
step and start by taking out the knight. Thus
Black plays BxN; and now if White recaptures with BxB, Black is free to play Rxg3+.
White then would have to reply f2xg3 (if he
instead tries Kh2, White looks for his next
check and finds Qxh4#). The board is set up
for the discovered check d4-d3+, winning the
queen.
The probable result of all this is that Black
simply takes White’s knight for free at the
outset; this is an example of the power of
working backwards from an idea, examining
the obstacles to its success and considering
how each might be removed. The threat can
lead to gains elsewhere on the board, since the
discovery hanging in the background leaves
other enemy pieces more vulnerable than they
seem.
Dg472: White to move
Dg471: White to move
Dg471: It's good practice to pay attention to
lines leading toward the enemy king, and to
see in a case like this that White has a bishop
bearing down on the diagonal where Black’s
king sits—and that the bishop is masked by
the pawn on d5. If the pawn could advance to
d6, the unmasked bishop would give check
and the pawn would take Black’s queen a
move later. The challenge is to get rid of the
bishop on d6 that blocks the pawn’s progress.
How? By capturing something it guards, naturally. One thing it protects is the rook on e7.
White can take it with QxR. After Black recaptures BxQ, White is free to move his pawn
to d6 and win back his queen after Black
moves his king. White nets a rook.
Dg472: White’s queen is aimed at Black’s
king and masked only by his pawn on e6. If
the pawn could move forward with a threat,
White would have an effective discovered
check. The e6 pawn can’t move forward because Black’s bishop is in the way; and if the
pawn were able to move forward it would
have no target (promoting on e8 isn't going to
work because Black will have the square
guarded). If those two problems are perceived
clearly it also becomes clear that they can be
solved at once if the bishop can be moved to
d8. Try putting a piece there to force a capture
on that square: Rd8+. Notice that with
White’s e6 pawn attacking the f7 square,
Black’s king is trapped on the back rank.
Black has to play BxR, and now the way is
clear for e6-e7+, with the pawn promoting via
e7xB on the next move.
The idea here might as well have emerged by
just looking at checks. White’s only one is
Rd8, and Black’s only defense is BxR. If you
imagine the resulting position clearly, the
discovered check for White is obvious.
Dg473: Black to move
Dg473: Black’s pieces are compressed, and it
might appear that his bishop on e7 mostly is
helping to protect the pawn on d6 and knight
on f6. But it is doing more: it aims through
the pawn at the White bishop on a3, which is
loose. After the d6 pawn marches forward to
attack White’s knight on e4, Black can play
BxB. But the board isn't ready for this yet;
White would be able to ignore the pawn and
play BxB himself. After Black plays the recapture NxB, White can move his e4 knight
away with no net loss. Black’s problem is that
his pawn needs a better target—one that requires immediate attention and thus creates
time for him to be the one to play BxB a
move later. The natural way to achieve this is
to capture the pawn’s current target with a
different piece and invite a recapture. Thus
Black starts with NxN. White has to either
forfeit the knight or recapture with his queen;
and if he does recapture QxN, the pawn advance d6-d5 now has a very different significance: White is forced to move his queen (and
he can’t move it anyplace where it can protect
the bishop) and then suffer the loss of a piece
with BxB.
square where you want it by putting one of
your own pieces there.
Thus suppose Black plays Rf2. What does
this threaten? Consider the best checks Black
would then have; he could play Qg2# or
Qxh2#. After Black starts with Rf2, White
can fend off that threat of Qg2# by playing
Rg1; now g2 is defended. But that doesn't
help with the threat of Qxh2#. The only way
for White to deal with that threat as well as
the threat of Qg2# is by responding to Rf2
with QxRf2. That does take care of both mating threats—but now Black's discovered
check e4-e3 wins the queen for a rook.
Dg475: White to move
Dg474: Black to move
Dg474: Black’s bishop is aimed at White’s
king with the usual pawn in the way. If
White’s queen were on d2 or f2 rather than
e3, Black would have a classic discovered
check with a threat against White’s queen.
Meanwhile Black also has two other pieces—
his rook and queen—trained on the White
king's territory. How to exploit all this? Use
one threat to improve the other. More specificially, try the same logic seen in the previous
frame, in which you draw the queen onto the
Dg475: White's bishop on b3 is masked by a
friendly pawn. It lacks a suitable target but is
aimed toward the Black king's general vicinity. The c4 pawn, which would do the unmasking, can attack Black’s bishop on d6—
not bad, but an upgrade of the target would be
nice. White goes to work at both ends of the
possible discovery. First comes 1. RxB, QxR
(improving the target White anticipates for his
pawn); then 2. Bxg7, which forces Kg8 (improving the target for the bishop once uncloaked). Notice that if White had started
with Bxg7 it would have been foiled by QxB;
by playing RxB first, White forces Black’s
queen to leave its defense of g7. So now both
pieces in the discovery have good targets: c4c5+ attacks Black’s queen with a pawn and
attacks his king with a bishop. Black has to
lose his queen for a bishop by moving it to d5.
Of course Black also can avoid much of this
by accepting the loss of his bishop on the first
move without a recapture—a satisfactory result for White.
Dg476: Black to move
Dg476: This time Black’s b7 pawn masks the
horizontal path of his queen. This idea would
most easily be triggered by the sight of
White’s bishop loose on a7; when the enemy
has a loose piece, you think hard about
whether any of your pieces can find a way to
attack it—including any pieces aimed at it
whose paths might be cleared somehow.
Black almost is ready to go with b7-b5, attacking White’s rook and unveiling the threat
of QxB. But consider White’s replies and
whether he would be able to go on the offensive himself, especially since Black’s move
wouldn’t give check. White would indeed be
able to play RxR+. Black then would have to
play QxR, ending the threat to White’s bishop
with no gain.
So again a preliminary exchange is in order to
upgrade the target: Black starts with RxR, and
after White recaptures with QxR the calculus
runs differently. White has no good answer to
b7-b5. He has to move his queen and endure
QxB by Black next move. (White would like
to move his queen someplace where it safely
can defend the bishop, but it has no such
square.)
Dg477: White is considering Ne5. A good
idea? No; for it is important to notice any discovery kernels your opponent has, not just
your own. Here Black’s bishop on b7 is
masked by his pawn on c6, and this represents
a major threat to White on the long diagonal.
While White’s king isn't on that diagonal at
the moment, he has to be wary of any moves
that would expose him to sequences following
the general pattern seen several times above.
If White's knight moves, it clears a piece from
that diagonal and the only thing then standing
between Black and a discovered check is the
need to draw the king onto g2—accomplished
easily enough by capturing the pawn on that
square and forcing a recapture with Qxg2+.
After KxQ, Black plays c6-c5, winning back
the queen and netting a pawn.
It might have occurred to you to worry as well
that after White’s Ne5, Black would play the
discovered mate threat c6-c5—threatening
Qxg2# without needing to move White’s king
into position. But this is another of those
cases where a mate threat is not as effective as
a check because it leaves White time to take
the initiative with a check of his own: Qxd7+,
with protection from the knight (which by
then is on e5). After Black’s king moves,
White has NxQ. So Black is better off replying with 1. ...Qxg2 as described above—and
you are better off assuming your opponent
will play the smart response to whatever you
do.
This batch of studies nicely illustrates the
power of a fianchettoed bishop—in other
words, a bishop moved from its original
square to b2 or g2 (for White) or b7 or g7 (for
Black).
3.4.4. Arranging Pawn Discoveries on
Ranks and Files.
Now consider what can happen when a pawn
unmasks an attack by another piece by clearing its file or rank.
Dg477: White to move
Dg478: White to move
Dg479: White to move
Dg478: The kernel of a pawn discovery takes
practice to see because it can look so unassuming. A pawn on the same rank or file as a
rook or queen, or on the same diagonal as a
bishop or queen: these are the patterns to absorb, and they usually look innocuous to the
untrained eye. The position to the left is a
good example. White’s queen is masked by
his pawn on f5 and an enemy pawn on f7.
True, White’s rook on d1 also is masked in a
somewhat similar way, but the queen is more
interesting because it's aimed at Black’s king.
A sequence that would clear the pawns from
the f-file might create a discovered check or
mate threat.
Dg479: White’s rook on f1 is blocked by his
pawn on f4—a common sort of occurrence.
What makes it interesting is that the pawn has
a way to clear the file and threaten Black’s
queen: f4xg5. To make this an effective double attack, of course, White needs a target for
his rook once the pawn moves off the file. We
look for ways to involve the enemy king, especially when it is so close to the relevant
line. Can it be moved from e8 to f8 or f7? The
obvious way to move a king is with a check,
but here White has none. Another way is to
plant a piece on the square where you want
the king to move—making either a threat or a
capture of your own in the process—and invite it to capture. The one way White can do
this is with Nf7. This forks Black’s queen,
bishop, and rook (the latter piece is loose),
and so requires Black’s immediate attention.
His only way to capture the knight is KxN,
after which White has the discovered check
f4xg5, winning the queen with the pawn
whether it stays where it is or moves to f6 to
block the check.
So how do you clear pawns from a file? The
answer is the same for your pawn and for
your opponent’s: they have to make captures.
One way to force that result is to take something a pawn protects; but another, useful
here, is to simply place a piece en prise to the
enemy pawn in a way that creates a threat and
requires the pawn to capture. A check is the
best example, and White has one that works
in this case: Ng6+, forking Black’s king and
queen. Black has to play f7xN. Now two
things have happened: the enemy pawn has
been cleared from f7, and White’s own pawn
on f5 has been given a way to get off that file
and make a threat: f5xg6+, which unmasks
check by White’s queen and also threatens
g6xR. The rook will be lost to the pawn,
whether it stays put or moves to f7 to block
the check.
Now suppose Black grasps this and so tries to
avoid KxN; does he have anything else in
reply to the fork White launches with Nf7?
Black would like to move the queen out of
danger and protect the two loose pieces
threatened by the knight. This can be done
with Qf6. But then White still wins the exchange with NxR.
Dg480: Black to move
Dg481: Black to move
Dg480: Here is something a little different.
You're playing the Black pieces. White
threatens your h5 rook with his bishop. Think
offense before defense; find the kernel of a
discovery. Your rook is aimed at the enemy
king and masked by the pawns on h4 and h2.
You study the king’s position and see that its
only flight square (g1) is sealed off by your
bishop. Play on the h-file might be indicated,
but how? There isn't yet any way for the pawn
on h4 to vacate the file, and then there still
would be a White pawn on h2. Both problems
would be cleared up, however, if the h2 pawn
could be goaded onto g3; then it would be out
of the way and the Black pawn on h4 would
have something to capture. So plant a piece
vulnerable to the pawn on h2, and do it with a
threat: Ng3+, a fork of bishop, rook, and king.
(If that line of reasoning was too cumbersome, try a simpler one: examine any checks
you can give and arrive at Ng3.)
Dg481: A queen or rook on a rank where it is
masked by a pawn is a good setup for a discovery; if the pawn moves (whether forward
or diagonally), the attack is unmasked. Here
Black's queen is on a5, masked by his pawn
on d5. The pawn can’t advance on the d-file,
but it can make a capture on c4, thus clearing
the queen’s path across the fifth rank and also
launching an attack of its own on White’s d3
bishop. All that needs to be considered is the
queen’s target. White has a bishop on g5. It’s
not loose, so if the queen were unmasked it
wouldn’t be able to make the capture. But the
bishop’s only guard is the knight on f3, and a
piece that is protected only by another piece
often can be weakened or left loose by a preliminary exchange—a capture of the guard, or
a capture of the target that requires its guard
to recapture and then be left loose. Here Black
thus starts by taking the bishop with NxB.
NxN follows for White—but now he has a
loose piece on g5. Black plays d5xc4, winning material no matter what White does.
So now consider White's replies. If he plays
QxN, fine; Black has h4xQ. But what if
White replies h2xN? Black plays the discovered check h4xg3. It isn't quite mate because
White still has BxR. But now look for Black’s
next possible check. It’s Qh4—and this time
it is mate, since Black’s bishop still seals off
the king’s only flight square. It’s a lesson in
the importance of noting how all of your
pieces bear on a position and might be
brought into the fray. The queen’s path from
its starting square to the side of the board (and
thus down the h-file) is a potent resource.
Dg482: White to move
Dg482: Of course White can simply take a
piece here with QxN+, and the temptation to
play that move would be sore. But pause be-
fore playing even such obviously attractive
moves to make sure you have nothing even
better. In this case it's especially important
because Black’s king is both exposed and
constrained; this can lead to trouble for him in
countless ways. The experiments begin by
looking at checks you can give and finding
Qf4+: safe checks you can give with your
queen always need to be examined with care.
This one forces Black to play his king to h5.
Look for your next check. Follow-ups with
your queen either lose the piece or are inconclusive, but don’t forget your pawns: White
has g2-g4+. Black’s pawn on f5 can’t very
well be used to recapture, as it now is pinned
to its queen, so Black’s king is forced back
down to h4 (h6 is under attack). See the resulting pattern in your mind’s eye: the king
ends up in the same position where it starts,
but now White has a queen on f4 and a pawn
on g4—the kernel of a discovered check on
the fourth rank. White simply steps the pawn
forward to g5, forcing the reply Kh5 and winning the queen (g5xQ) next move.
The position is a final illustration of a valuable skill: the ability to see possible discoveries arise during the forced sequences you
imagine. You think of a check, then your next
one; but do you notice that one of your pieces
has moved in front of another, making a new
sort of threat possible? Consider this batch of
studies—and this last one in particular—a
way to build your instinct for that pattern.
3.4.5. Strategy and the Discovered Attack.
Mastering the discovered attack partly is a
matter of getting to know each of your pieces
again—as maskers of attacks by other pieces.
Thus you may at first think of the bishop as a
piece that attacks along diagonals and create
double attacks of the sort we saw in the chapter on bishop forks. That’s accurate as far as it
goes, but another part of the bishop's power
comes from its ability to unmask attacks
along files and ranks by rooks and queens.
When you look at a bishop you want to see
more or less automatically not only where it is
aimed but also whether any heavy pieces lie
on the rank or file where it resides. You likewise want your eyes trained to notice when a
bishop or queen lies on the same diagonal as
one of your rooks; and when a rook, bishop,
or queen lies on the same line with one of
your knights; and when one of your pawns
conceals a bishop on its diagonal or a rook or
queen on its file. You get the idea: sensitize
yourself in general to alignments of your
pieces and your opponent’s pieces—both on
the board in front of you and on the board as
it would look after one or several moves in a
series you imagine. Noticing alignments is the
key to seeing chances for discovered attacks.
It also is the key to seeing chances for pins
and skewers, as we will learn in more detail in
the next section.
The execution of a discovery is a climactic
moment during a game; on most of your
moves you will have no such opportunity. So
what do you do then when you have no way
to win material with tactical strikes? You play
strategically, making positional moves that
increase the strength of your pieces and make
eventual tactical shots more likely. From our
studies of discovered attacks we can infer
some lessons about sound strategic play: the
significance of open lines; the usefulness of
centralizing your pieces; and the importance
of a king’s vulnerabilities. Each of these considerations can be seen from an offensive or
defensive standpoint, but for present purposes
we mostly will look at them from an offensive
point of view.
Discovered checks by bishops require, first,
open lines for the rooks and queens that the
bishops unmask—in other words, lines unobstructed by pawns. Think first about open
files. Rooks depend on them; one thing you
learn early in chess is that as powerful as
rooks seem to be, they usually do little good
so long as they sit behind pawns (unless the
pawn is on its way to promotion, but set that
possibility to one side for now). Moving a
rook to an open file thus vastly increases its
strength. Another thing you soon notice is that
getting two rooks onto the same open line
multiplies their powers further. The point of
our studies here is that discovered attacks are
still another way to play on open files. You
can put a bishop or knight there in front of
your rook or queen, or in front of the squares
where your rooks or queen may go; in this
way you create potential energy on the file, as
you have the makings of a double attack of
the discovered variety if targets can be
brought into view at both ends.
The same goes for diagonals. You can play on
a diagonal not only by putting a bishop there
or a bishop plus a queen, but also by putting a
rook or knight in front of those pieces. The
rook or knight can't travel on the diagonal, of
course, but can jump from it and thus create
two attacks at once: the tactician’s dream.
Once you appreciate the great uses of open
lines, the next question is how to create them.
It’s all about pawns. If there are no open files
and diagonals, your job is to create them
through pawn warfare. Often a pawn move or
exchange will be most significant because it
will open a file halfway (eliminating one of
the pawns on it) or completely (eliminating
both pawns), leaving it open for occupation
and domination by a rook. Pawns also determine whether diagonals are available for your
bishops, whether to create forks or pins or—
here—discoveries. This is especially true
when either side has a cluster or “phalanx” of
pawns, as pawns so arranged will tend to sit
on squares of the same color; that is how they
protect each other. Their arrangement will
determine whether the bishops that travel on
those squares will be active or inert. The lesson is to think about the implications of pawn
moves and exchanges for the mobility of your
rooks and bishops—and those of your opponent.
So getting your pieces onto open lines is one
way to create a fertile environment for discoveries. Another element is centralization —
establishing pieces near the middle of the
board. A discovery requires an arrangement
of three pieces: an attacker, a target, and a
piece of yours that lies between them and that
can leap out of the way. We have seen lots of
ways those pieces can be arranged; they all
can be clustered at one end of the board, or
two can be at one end and one at the other.
But in general a knight is most likely to be in
position to unmask an attack by another piece
when it is more or less centralized, for when it
is near the middle of the board it has the best
chance of ending up between a friendly and
an enemy piece. The same principle holds for
most of other pieces when acting as unmaskers. Rooks need lines unblocked by pawns
before they can be unmasked and threaten
anything. But if a rook is going to unmask an
attack by a bishop, it needs more than an open
line; it needs to get out onto the board where
it can get in front of a bishop or queen.
Finally there is the matter of targets. We have
seen many times that a good place to start
looking for tactical opportunities is the enemy
king's position: its exposure, ways that it can
be forced to move, or that lines toward it can
be opened. The point of the investigations is
not necessarily the thought of checkmate,
which may be nowhere in sight. The point is
that double attacks of all kinds—including
discoveries—work best when the enemy king
is at one end of them because your opponent’s
choice of replies is then so limited.
The point has several implications for strategic play. One is the value defensively of castling early, and the advantage to be had if you
can prevent castling by the other side. Disrupting the pawn cover in front of the enemy
king likewise can have great value, as the
king then becomes more exposed as a target
at one end of discoveries you may arrange (as
well as forks and pins). There are lots of ways
to ruin a king's pawn cover; some of them
involve sacrifices, usually as a run-up to a
tactical blow you have planned. But on occasion you may be able to tear the cover apart
without a sacrifice, and without any particular
follow-up in mind, just by forcing exchanges
of pieces that are protected by the pawns in
front of his king, or by sending your own
pawns forward to harass those of the enemy.
Another related point is the value of coordinating your pieces to create pressure on the
enemy king’s position. This is not always the
best strategy; sometimes the king’s position is
secure and your advantages lie elsewhere on
the board. You make plans in the sectors
where you have the best promise of success.
But offensive pressure against the enemy king
can create prospects for all kinds of tactics
that involve busying your opponent with
threats in one place while you also create simultaneous threats elsewhere. Forks are one
example; discoveries are another. And having
pieces coordinated—i.e., aimed at the same
area of the board, or otherwise supporting
each other's work—tends to be a lot more
valuable than having them fire in different
directions, in part because their powers can
then be combined to make those tactical shots
work. Maybe one piece makes a sacrifice to
set up a target for another; maybe two of them
combine to create a mating threat while also
making a threat elsewhere; maybe one can
mask and unmask the other.