James Parsons
Mathematics
• Numerical Analysis
•Applied Numerical Analysis
•Sabermetrics
 Earnshaw
Cook – starting researching in
the middle of the 20th century.
 Sabermetrics
is the search for objective
knowledge about baseball
 Sabermetrics
comes from the acronym
SABR (Society for American Baseball
Research) coined by Bill James
 BB – Base on Balls
 HBP – Hit by Pitch
 SF – Sacrifice Fly
 H – Hits
 RBOE – Reach based on
 1B – Single
 2B – Double
 3B – Triple
 HR – Home Run
 TB – Total Bases
 AB – At Bats
 PA – Plate appearance
Error
Baseball
Offense
Defense
Pitching

OPS = OBP + SLG

SLG = TB / AB
• TB = 1B + 2(2B) + 3(3B) + 4(HR)

OBP = (H + BB + HBP) / (AB +BB + SF + HBP)

Example: 2013 Miguel Cabrera (DET)
SLG = (122 + 2(26) + 3(1) + 4(44)) / 555 = .636
 OBP = (193 + 90 + 5) / (555 + 90 + 2 + 5) = .442
 OPS = .636 + .442 = 1.078


The equation was developed by Tom Tango who cowrote The Book: Playing the Percentages in Baseball

wOBA = (.72 * BB) + (.75 * HBP) + (.9 * 1B) + (.92 *
RBOE) + (1.24 * 2B) + (1.56 * 3B) + (1.95 * HR) / PA

2013 Mike Trout (LAA):
• wOBA: =((.72* 110) + (.75*9) + (.9*115)+ (.92*RBOE) + (1.24
*39) + (1.56*9) + (1.95*27) ) / 716
= .425 + (.92*RBOE)

The constants are changing each year so each year
the wOBA changes each year.
 2003 Baseball Season
• Movie: Moneyball
 2003
Oakland Athletics payroll just under
$50 million dollars
• Record : 96-66
 2003
New York Yankees payroll just under
$170 million dollars (3.44x more)
• Record: 101-61
 At
the end of each season the statistics
that were calculated are reverted back to
zero.
 Baseball is unpredictable.
 Getting
a limited amount of data points