What’s wrong with the OPS analysis in baseball
Keith R. Thompson,
January 2008
In recent years the OPS ratio in Baseball (On-Base
Plus
Slugging Percentage) has gained widespread acceptable as an
analytical tool in evaluating a player’s skills. The argument is
that it effectively captures the ability of a player to both get on
base and hit for power – two very valuable hitting skills. The
alleged value of the tool is also compounded by the fact that an OPS
of .900 or higher typically puts the hitter in the upper echelon of
offensive ability, with the league leaders in OPS generally scoring
at or near the 1.000 mark.
The
following table shows the overall MLB leaders in OPS during the 2007
season:
|
Rank
|
Player
|
Team
|
Runs
|
RBI
|
BA
|
OBP
|
SLG
|
OPS
|
|
1
|
Alex Rodriguez
|
NYY
|
143
|
156
|
0.314
|
0.422
|
0.645
|
1.067
|
|
2
|
David Ortiz
|
BOS
|
116
|
117
|
0.332
|
0.445
|
0.621
|
1.066
|
|
3
|
Carlos Pena
|
TAM
|
99
|
121
|
0.282
|
0.411
|
0.627
|
1.037
|
|
4
|
Chipper Jones
|
ATL
|
108
|
102
|
0.337
|
0.425
|
0.604
|
1.029
|
|
5
|
Magglio Ordonez
|
DET
|
117
|
139
|
0.363
|
0.434
|
0.595
|
1.029
|
|
6
|
Prince Fielder
|
MIL
|
109
|
119
|
0.288
|
0.395
|
0.618
|
1.013
|
|
7
|
Matt Holliday
|
COL
|
120
|
137
|
0.340
|
0.405
|
0.607
|
1.012
|
|
8
|
Albert Pujols
|
STL
|
99
|
103
|
0.327
|
0.429
|
0.568
|
0.997
|
|
9
|
Chase Utley
|
PHI
|
104
|
103
|
0.332
|
0.410
|
0.566
|
0.976
|
|
10
|
Ryan Howard
|
PHI
|
94
|
136
|
0.268
|
0.392
|
0.584
|
0.976
|
|
The result shows that the OPS measure (while a good indicator of hitting
and slugging) does not correlate well with other success metrics
such as runs scored and RBIs. In 2007 Alex Rodriguez led the majors
in OPS, RBIs and Runs Scored. However, among the rest of the players
within the OPS ton ten only two others (Magglio Ordonez and Matt
Holliday) were also in the top ten in RBIs and Runs Scored. In fact,
the player with the second-highest ranked OPS – David Ortiz – was
only ranked 11th and 10th in RBIs and Runs Scored respectively. And Carlos Pena, with the third-highest OPS
score was only 31st in Runs Scored in the majors in 2007.
In case one was wondering whether the results of 2007 were an aberration,
consider these facts for the top ten OPS leaders during the first
decade of the 20th century.
|
2006 Season
|
|
|
Rank
|
Player
|
Team
|
Runs
|
RBI
|
BA
|
OBP
|
SLG
|
OPS
|
|
|
1
|
Albert Pujols
|
STL
|
119
|
137
|
0.331
|
0.431
|
0.671
|
1.102
|
|
|
2
|
Travis Hafner
|
CLE
|
100
|
117
|
0.308
|
0.439
|
0.659
|
1.097
|
|
|
3
|
Ryan Howard
|
PHI
|
104
|
149
|
0.313
|
0.425
|
0.659
|
1.084
|
|
|
4
|
Manny Ramirez
|
BOS
|
79
|
102
|
0.321
|
0.439
|
0.619
|
1.058
|
|
|
5
|
David Ortiz
|
BOS
|
115
|
137
|
0.287
|
0.413
|
0.636
|
1.049
|
|
|
6
|
Lance Berkman
|
HOU
|
95
|
136
|
0.315
|
0.420
|
0.621
|
1.041
|
|
|
7
|
Jim Thome
|
CHW
|
108
|
109
|
0.288
|
0.416
|
0.598
|
1.014
|
|
|
8
|
Jermaine Dye
|
CHW
|
103
|
120
|
0.315
|
0.385
|
0.622
|
1.006
|
|
|
9
|
Miguel Cabrera
|
FLA
|
112
|
114
|
0.339
|
0.430
|
0.568
|
0.998
|
|
|
10
|
Carlos Beltran
|
NYM
|
127
|
116
|
0.275
|
0.388
|
0.594
|
0.982
|
|
|
|
|
|
|
|
|
|
|
|
|
2005 Season
|
|
|
Rank
|
PLAYER
|
TEAM
|
Runs
|
RBI
|
BA
|
OBP
|
SLG
|
OPS
|
|
|
1
|
Derrek Lee
|
CHC
|
120
|
107
|
0.335
|
0.418
|
0.662
|
1.080
|
|
|
2
|
Albert Pujols
|
STL
|
129
|
117
|
0.330
|
0.430
|
0.609
|
1.039
|
|
|
3
|
Alex Rodriguez
|
NYY
|
124
|
130
|
0.321
|
0.421
|
0.610
|
1.031
|
|
|
4
|
Travis Hafner
|
CLE
|
94
|
108
|
0.305
|
0.408
|
0.595
|
1.003
|
|
|
5
|
David Ortiz
|
BOS
|
119
|
148
|
0.300
|
0.397
|
0.604
|
1.001
|
|
|
6
|
Manny Ramirez
|
BOS
|
112
|
144
|
0.292
|
0.388
|
0.594
|
0.982
|
|
|
7
|
Carlos Delgado
|
FLA
|
81
|
115
|
0.301
|
0.399
|
0.582
|
0.981
|
|
|
8
|
Todd Helton
|
COL
|
92
|
79
|
0.320
|
0.445
|
0.534
|
0.979
|
|
|
9
|
Jason Giambi
|
NYY
|
74
|
87
|
0.271
|
0.440
|
0.535
|
0.975
|
|
|
10
|
Jason Bay
|
PIT
|
110
|
101
|
0.306
|
0.402
|
0.559
|
0.961
|
|
|
|
|
|
|
|
|
|
|
|
|
2004 Season
|
|
|
Rank
|
PLAYER
|
TEAM
|
Runs
|
RBI
|
BA
|
OBP
|
SLG
|
OPS
|
|
|
1
|
Barry Bonds
|
SFO
|
129
|
101
|
0.362
|
0.609
|
0.812
|
1.422
|
|
|
2
|
Todd Helton
|
COL
|
115
|
96
|
0.347
|
0.469
|
0.620
|
1.088
|
|
|
3
|
Albert Pujols
|
STL
|
133
|
123
|
0.331
|
0.415
|
0.657
|
1.072
|
|
|
4
|
Jim Edmonds
|
STL
|
102
|
111
|
0.301
|
0.418
|
0.643
|
1.061
|
|
|
5
|
Adrian Beltre
|
LOS
|
104
|
121
|
0.334
|
0.388
|
0.629
|
1.017
|
|
|
6
|
Lance Berkman
|
HOU
|
104
|
106
|
0.316
|
0.450
|
0.566
|
1.016
|
|
|
7
|
Manny Ramirez
|
BOS
|
108
|
130
|
0.308
|
0.397
|
0.613
|
1.009
|
|
|
8
|
Scott Rolen
|
STL
|
109
|
124
|
0.314
|
0.409
|
0.598
|
1.007
|
|
|
9
|
J.D. Drew
|
ATL
|
118
|
93
|
0.305
|
0.436
|
0.569
|
1.006
|
|
|
10
|
Travis Hafner
|
CLE
|
96
|
109
|
0.311
|
0.410
|
0.583
|
0.993
|
|
|
|
|
|
|
|
|
|
|
|
|
2003 Season
|
|
|
Rank
|
PLAYER
|
TEAM
|
Runs
|
RBI
|
BA
|
OBP
|
SLG
|
OPS
|
|
|
1
|
Barry Bonds
|
SFO
|
111
|
90
|
0.341
|
0.529
|
0.749
|
1.278
|
|
|
2
|
Albert Pujols
|
STL
|
137
|
124
|
0.359
|
0.439
|
0.667
|
1.106
|
|
|
3
|
Todd Helton
|
COL
|
135
|
117
|
0.358
|
0.458
|
0.630
|
1.088
|
|
|
4
|
Gary Sheffield
|
ATL
|
126
|
132
|
0.330
|
0.419
|
0.604
|
1.023
|
|
|
5
|
Carlos Delgado
|
TOR
|
117
|
145
|
0.302
|
0.426
|
0.593
|
1.019
|
|
|
6
|
Manny Ramirez
|
BOS
|
117
|
104
|
0.325
|
0.427
|
0.587
|
1.014
|
|
|
7
|
Jim Edmonds
|
STL
|
89
|
89
|
0.275
|
0.385
|
0.617
|
1.002
|
|
|
8
|
Alex Rodriguez
|
TEX
|
124
|
118
|
0.298
|
0.396
|
0.600
|
0.995
|
|
|
9
|
Trot Nixon
|
BOS
|
81
|
87
|
0.306
|
0.396
|
0.578
|
0.975
|
|
|
10
|
David Ortiz
|
BOS
|
79
|
101
|
0.288
|
0.369
|
0.592
|
0.961
|
|
|
|
|
|
|
|
|
|
|
|
|
2002 Season
|
|
|
Rank
|
PLAYER
|
TEAM
|
Runs
|
RBI
|
BA
|
OBP
|
SLG
|
OPS
|
|
|
1
|
Barry Bonds
|
SFO
|
117
|
110
|
0.370
|
0.582
|
0.799
|
1.381
|
|
|
2
|
Jim Thome
|
CLE
|
101
|
118
|
0.304
|
0.445
|
0.677
|
1.122
|
|
|
3
|
Manny Ramirez
|
BOS
|
84
|
107
|
0.349
|
0.450
|
0.647
|
1.097
|
|
|
4
|
Brian Giles
|
PIT
|
95
|
103
|
0.298
|
0.450
|
0.622
|
1.072
|
|
|
5
|
Jason Giambi
|
NYY
|
120
|
122
|
0.314
|
0.435
|
0.598
|
1.034
|
|
|
6
|
Larry Walker
|
COL
|
95
|
104
|
0.338
|
0.421
|
0.602
|
1.023
|
|
|
7
|
Alex Rodriguez
|
TEX
|
125
|
142
|
0.300
|
0.392
|
0.623
|
1.015
|
|
|
8
|
Vladimir Guerrero
|
MON
|
106
|
111
|
0.336
|
0.417
|
0.593
|
1.010
|
|
|
9
|
Todd Helton
|
COL
|
107
|
109
|
0.329
|
0.429
|
0.577
|
1.006
|
|
|
10
|
Sammy Sosa
|
CHC
|
122
|
108
|
0.288
|
0.399
|
0.594
|
0.993
|
|
|
|
|
|
|
|
|
|
|
|
|
2001 Season
|
|
|
Rank
|
PLAYER
|
TEAM
|
Runs
|
RBI
|
BA
|
OBP
|
SLG
|
OPS
|
|
|
1
|
Barry Bonds
|
SFO
|
129
|
137
|
0.328
|
0.515
|
0.863
|
1.379
|
|
|
2
|
Sammy Sosa
|
CHC
|
146
|
160
|
0.328
|
0.437
|
0.737
|
1.174
|
|
|
3
|
Jason Giambi
|
OAK
|
109
|
120
|
0.342
|
0.477
|
0.660
|
1.137
|
|
|
4
|
Luis Gonzalez
|
ARI
|
128
|
142
|
0.325
|
0.429
|
0.688
|
1.117
|
|
|
5
|
Todd Helton
|
COL
|
132
|
146
|
0.336
|
0.432
|
0.685
|
1.116
|
|
|
6
|
Larry Walker
|
COL
|
107
|
123
|
0.350
|
0.449
|
0.662
|
1.111
|
|
|
7
|
Lance Berkman
|
HOU
|
110
|
126
|
0.331
|
0.430
|
0.620
|
1.051
|
|
|
8
|
Jim Thome
|
CLE
|
101
|
124
|
0.291
|
0.416
|
0.624
|
1.040
|
|
|
9
|
Chipper Jones
|
ATL
|
113
|
102
|
0.330
|
0.427
|
0.605
|
1.032
|
|
|
10
|
Alex Rodriguez
|
TEX
|
133
|
135
|
0.318
|
0.399
|
0.622
|
1.021
|
|
|
|
|
|
|
|
|
|
|
|
|
2000 Season
|
|
|
Rank
|
PLAYER
|
TEAM
|
Runs
|
RBI
|
BA
|
OBP
|
SLG
|
OPS
|
|
|
1
|
Todd Helton
|
COL
|
138
|
147
|
0.372
|
0.463
|
0.698
|
1.162
|
|
|
2
|
Manny Ramirez
|
CLE
|
92
|
122
|
0.351
|
0.457
|
0.697
|
1.154
|
|
|
3
|
Carlos Delgado
|
TOR
|
115
|
137
|
0.344
|
0.470
|
0.664
|
1.134
|
|
|
4
|
Barry Bonds
|
SFO
|
129
|
106
|
0.306
|
0.440
|
0.688
|
1.127
|
|
|
5
|
Jason Giambi
|
OAK
|
108
|
137
|
0.333
|
0.476
|
0.647
|
1.123
|
|
|
6
|
Gary Sheffield
|
LOS
|
105
|
109
|
0.325
|
0.438
|
0.643
|
1.081
|
|
|
7
|
Vladimir Guerrero
|
MON
|
101
|
123
|
0.345
|
0.410
|
0.664
|
1.074
|
|
|
8
|
Frank Thomas
|
CHW
|
115
|
143
|
0.328
|
0.436
|
0.625
|
1.061
|
|
|
9
|
Sammy Sosa
|
CHC
|
106
|
138
|
0.320
|
0.406
|
0.634
|
1.040
|
|
|
10
|
Jeff Bagwell
|
HOU
|
152
|
132
|
0.310
|
0.424
|
0.615
|
1.039
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
In 2006 only one player (Albert Pujols) ranked in the top ten in OPS, RBIs
and Runs Scored.
In 2005
four hitters (Pujols, Alex Rodriguez, David Ortiz and Manny Ramirez)
ranked in the top ten in all three categories.
In 2004
only Pujols again ranked in the top ten in all three categories.
In 2003
five hitters (Pujols, Rodriguez, Todd Helton, Gary Sheffield and
Carlos Delgado) ranked in the top ten in all three categories.
In 2002 only Alex Rodriguez and Jason Giambi ranked in the top ten in all
three categories.
In 2001
five hitters ranked in the top ten in all three categories.
In 2000
Todd Helton and Jeff Bagwell were the only hitters ranked in the top
ten in all three categories.
What then do we make of the OPS statistic. Since 2000 in less than 30% of the
time does a player ranked in the top ten in OPS also rank in the top
ten in Runs scored and RBIs. OPS is therefore a poor measure of players’
performance when it comes to run contribution (whether scored or
driven in). Given that runs is the true determination of wins and
losses then shouldn’t we be utilizing a metric other than OPS that
also considers the hitter’s ability to score runs and contribute via
RBIs.
The
second
limitation of OPS is that it
double-counts the number of hits that a player has. Since the total
number of hits is already counted in both on-base average and
slugging percentage then using OPS will naturally be biased towards
players with a high batting average.
There is
also a third limitation of the OPS measure. At its heart it
aggregates On-Base Percentage (which divides Hits, Walks and
Hit-by-Pitch by a measure resembling total Plate Appearances) and
Slugging Percentage (which takes Total bases and divides by total
At-Bats). This is like adding apples and oranges.
The
denominator for On-Base Percentage is Plate Appearances, whereas it
is At-Bats for Slugging Percentage. It is a basic premise of
addition that one cannot add two fractions with different
denominators unless certain adjustments are first made. Again, it is
like adding apples and oranges.
What does an OPS of 1.000 mean, for eg.
Intuitively we know that a batting average of 0.300 represents
three hits in ten at-bats. An on-base average of 0.400 means getting
on-base in 4 out of every ten plate appearances. And a slugging percentage of 0.600 (or 60%) means 6 total bases
for every ten at-bats. However, an OPS of 1.000 means what exactly? Does it
mean 1 hit for every at-bat. NO. Then does it mean 1 time on base for every plate
appearance. Definitely Not. Well then
it means
absolutely nothing since its adding two very different numbers.
The OPS adds two fractions with different denominators which
renders it practically meaningless. Literally like adding apples and oranges. Hence
the results cannot be properly interpreted.
Therefore the statistic called OPS
is not a true statistical measure. Just because it may produce
plausible results from time to time does not mean that it is an
accurate measure. Likewise, the OPS with all its flaws is also
limited in its ability to indicate the top run contributors in the
game.
© 2008 PER Sports, Inc.
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