On-base plus slugging, or OPS, is a baseball statistic which is calculated as the sum of a player's on-base percentage and slugging percentage.^{[1]} Both the ability of a player to get on base and to hit for power, two important hitting skills, are represented, making it an effective way of measuring the offensive worth of a player. An OPS of .900 or higher in Major League Baseball puts the player in the upper echelon of offensive ability. Typically, the league leader in OPS will hover near the 1.000 mark.
Formula
The basic formula is
$ OPS = OBP + SLG $
where OBP is on-base percentage, and SLG is slugging percentage. These percentages are defined as
$ SLG = \frac{TB} {AB} $
and
$ OBP = \frac{H+BB+HBP} {AB+BB+SF+HBP} $
where:
- H = Hits
- BB = Bases on balls
- HBP = Times hit by pitch
- AB = At bats
- SF = Sacrifice flies
- TB = Total bases
Since OBP and SLG have different denominators, it is possible to rewrite the expression for OPS using a common denominator. This expression is mathematically identical to the simple sum of OBP and SLG:
$ OPS = \frac{AB(H+BB+HBP)+TB(AB+BB+SF+HBP)}{AB(AB+BB+SF+HBP)} $
Interpretation of OPS
It should be noted that unlike many other statistics, a player's OPS does not have a simple intrinsic meaning, despite its usefulness as a comparative statistic.
One fault of OPS is that it weights on-base average and slugging percentage equally, although on-base average correlates better with scoring runs. Magnifying this fault is that the component parts of OPS are not themselves typically close to equal numerically (league-average slugging percentages are usually 75-100 points higher than league-average on-base percentages, while league-leading slugging percentages are often 200-300 points higher than league-leading on-base percentages). However, the simplicity of the formula, and its high correlation to offensive ability have made it popular among fans.
Discrepancies between published OPSes and the sum of on-base average and slugging percentage are due to rounding errors.
History
On-base plus slugging was first popularized in 1984 by John Thorn and Pete Palmer's book, The Hidden Game of Baseball.^{[2]} The New York Times then began carrying the leaders in this statistic in its weekly "By the Numbers" box, a feature that ran for four years. Baseball journalist Peter Gammons used and evangelized the statistics, and other writers and broadcasters picked it up. The popularity of OPS gradually spread, and by 2004 it began appearing on Topps baseball cards.^{[3]}
Leaders
The Major League Baseball players with a lifetime OPS higher than 1.000 are (through 2005, active players in bold):
- Babe Ruth, 1.1636
- Ted Williams, 1.1155
- Lou Gehrig, 1.0798
- Barry Bonds, 1.0533
- Albert Pujols, 1.0490
- Todd Helton, 1.0404
- Jimmie Foxx, 1.0376
- Hank Greenberg, 1.0169
- Rogers Hornsby, 1.0103
- Manny Ramírez, 1.0076
Albert Pujols has the highest career OPS for a right-handed batter.
The top ten single-season performances in MLB are (all left-handed hitters):
- Barry Bonds, 1.4217 (2004)
- Barry Bonds, 1.3807 (2002)
- Babe Ruth, 1.3791 (1920)
- Barry Bonds, 1.3785 (2001)
- Babe Ruth, 1.3586 (1921)
- Babe Ruth, 1.3089 (1923)
- Ted Williams, 1.2874 (1941)
- Barry Bonds, 1.2778 (2003)
- Babe Ruth, 1.2582 (1927)
- Ted Williams, 1.2566 (1957)
The highest single-season mark for a right-handed hitter was 1.2449 by Rogers Hornsby in 1925 (13th on the all-time list). Since 1925, the highest single-season OPS for a right-hander is 1.2224 by Mark McGwire in 1998.
Adjusted OPS (OPS+)
OPS+, Adjusted OPS, is a closely related statistic. OPS+ is OPS adjusted for the park and the league in which the player played, but not for fielding position. An OPS+ of 100 is defined to be the league average. An OPS+ of 150 or more is excellent, signifying that the player had a 50% higher OPS than average, adjusted for park.
Leaders in OPS+
Through 2005, according to www.baseballreference.com the career leaders in OPS+ (minimum 3000 plate appearances, active players in bold) were
- Babe Ruth, 207
- Ted Williams, 190
- Barry Bonds, 184
- Lou Gehrig, 179
- Rogers Hornsby, 175
- Mickey Mantle, 172
- Albert Pujols, 171
- Dan Brouthers, 170
- Joe Jackson, 170
- Ty Cobb, 167
The highest single-season performances were:
- Barry Bonds, 275 (2002)
- Barry Bonds, 262 (2001)
- Barry Bonds, 260 (2004)
- Babe Ruth, 256 (1920)
- Fred Dunlap, 250 (1884)
- Babe Ruth, 239 (1921)
- Babe Ruth, 239 (1923)
- Ted Williams, 235 (1941)
- Ted Williams, 233 (1957)
- Ross Barnes, 231 (1876)
- Barry Bonds, 231 (2003)
See also
Notes
- ↑ See www.baseballprospectus.com or rec.sport.baseball.
- ↑ John Thorn and Pete Palmer, The Hidden Game of Baseball, pp. 69-70.
- ↑ Alan Schwarz, The Numbers Game, pp. 165, 233.
References
- Thorn, John; Pete Palmer (1984). The Hidden Game of Baseball. Doubleday & Company. ISBN 0-385-18283-X.
- Schwarz, Alan (2004). The Numbers Game. Thomas Dunne Books. ISBN 0-312-32222-4.