MoneyBall
Group 2
R04548005 白書齊
R04548003 呂冠儀
2015 CPBL
Trailer: Moneyball
Rule
1 inning - 3 outs
1 game - 9 innings
1 season - 162 games
• Batting Average(AVG)
𝐻
𝐴𝑉𝐺 =
𝐴𝐵
• On Base Percentage(OBP)
𝐻+𝐵𝐵+𝐻𝐵𝑃
𝑂𝐵𝑃 =
𝐴𝐵+𝐵𝐵+𝐻𝐵𝑃+𝑆𝐹
• Slugging percentage(SLG)
𝑇𝐵
𝑆𝐿𝐺 =
𝐴𝐵
payroll numbers in 2002
Team
Wins
Losses
Payroll
Cost Per Win
(millions)
Oakland Athletics
103
59
$40,004,167
$0.388
New York Yankees
103
58
$125,928,583
$1.223
Atlanta Braves
101
59
$93,470,367
$0.925
Team
Wins
Losses
Payroll
Cost Per Win
(millions)
New York Yankees
103
58
$125,928,583
$1.223
Boston Red Sox
93
69
$108,366,060
$1.165
Texas Rangers
72
90
$105,726,122
$1.468
Math Techniques - Sabermetrics
Pythagorean expectation:
Win =
𝑟𝑢𝑛𝑠 𝑠𝑐𝑜𝑟𝑒𝑑 2
𝑟𝑢𝑛𝑠 𝑠𝑐𝑜𝑟𝑒𝑑 2 +𝑟𝑢𝑛𝑠 𝑎𝑙𝑙𝑜𝑤𝑒𝑑 2
=
1
1+ 𝑟𝑢𝑛𝑠 𝑎𝑙𝑙𝑜𝑤𝑒𝑑/𝑟𝑢𝑛𝑠 𝑠𝑐𝑜𝑟𝑒𝑑 2
Runs Created:
RC = 𝑇𝐵 ∗
𝐻+𝐵𝐵
=
𝐴𝐵+𝐵𝐵
𝑂𝐵𝑃 ∗ 𝑆𝐿𝐺 ∗ 𝐴𝐵
A guide to Sabermetrics Research|SABR
Bill James 1977
Prediction
25 players
OBP = 0.34064
TB = 2400
 RC = 817.536
2002
Win =
1
1+ 𝑟𝑢𝑛𝑠 𝑎𝑙𝑙𝑜𝑤𝑒𝑑/𝑟𝑢𝑛𝑠 𝑠𝑐𝑜𝑟𝑒𝑑 2
RC = 𝑂𝐵𝑃 ∗ 𝑆𝐿𝐺 ∗ 𝐴𝐵
Team
Win
Lose
PCT
Avg.
OBP.
SLG.
AB
R
RA
Cal.
PCT
Ca. R
NYK
103
58
.640
.275
.354
.455
5601
897
697
.624
902.15
OKA
103
59
.636
.261
.339
.432
5558
800
654
.599
813.96
𝟗𝟗
= 𝟎. 𝟔𝟏𝟏
𝟏𝟔𝟐
𝟏
𝟏 + 𝒓𝒖𝒏𝒔 𝒂𝒍𝒍𝒐𝒘𝒆𝒅/𝒓𝒖𝒏𝒔 𝒔𝒄𝒐𝒓𝒆𝒅
𝒓𝒖𝒏𝒔 𝒂𝒍𝒍𝒐𝒘𝒆𝒅 𝒓𝒖𝒏𝒔 𝒔𝒄𝒐𝒓𝒆𝒅 <
𝟐
> 𝟎. 𝟔𝟏𝟏
𝟏
− 𝟏 ≈ 𝟎. 𝟕𝟗𝟖
. 𝟔𝟏𝟏
Moneyball Strategy
Year
Win
Lose
PCT.
Place
OBP
SLG.
AB
R
RA
Cal.PCT
Cal.R
2015
68
94
.420
5
.312
.395
5600
694
729
.475
690.14
2014
88
74
.543
2
.320
.381
5545
729
572
.619
676.05
2013
96
66
.593
1
.327
.419
5521
767
625
.600
756.45
2012
94
68
.580
1
.310
.404
5527
713
614
.574
692.20
2011
74
88
.457
3
2010
81
81
.500
2
2009
75
87
.463
4
2008
75
86
.466
3
2007
76
86
.469
3
2006
93
69
.574
1
.340
.412
5500
771
727
.529
770.44
2005
88
74
.543
2
.330
.407
5627
772
658
.579
755.76
2004
91
71
.562
2
.343
.433
5728
793
742
.533
850.72
2003
96
66
.593
1
.327
.417
5497
768
643
.606
749.56
2002
103
59
.636
1
.339
.432
5558
800
654
.599
813.96
2001
102
60
.630
2
.350
.458
5600
897
645
.659
897.68
Comparison between Sabermetrics &
Results
0.7
950
0.65
900
14%
0.6
850
0.55
800
0.5
750
7%
PCT.
0.45
Cal.PCT
0.4
R
700
Cal.R
650
2001 2002 2003 2004 2005 2006 2012 2013 2014 2015
2001
2002
2003
2004
2005
2006
2012
2013
2014
2015
Discussion
• It is verified that calculated RC % win rate are close to real records.
• Sabermetrics is reliable with lots of games.
• It wins the greatest profit with the lowest cost.
• The hypothesis of every player’s stable performance is not suitable for
long-term games.
• It is not available in short-term games.
Reference
• Runs Created Calculator & Formula
• MATH GOES POP
• A guide to Sabermetrics Research|SABR
• 2002 Oakland Athletics season Wikipedia
• The Wall Street Journal - Baseball after money
• 為什麼我們很難像《魔球》一樣點石成金？——談大數據的機會與挑戰
• [數據]怎麼看數字 - Sabermetrics
Thank you for your attention.