The basic equation is where OBP is on-base percentage and SLG is slugging average. These averages are defined. - the numerator "H + BB +HBP" effectively means "number of trips to first base at least" - the denominator "AB + BB + SF +HBP" effectively means "total plate appearances" - this is because though a batter makes a trip to the plate he is not given an "AB" when he walks or when he hits the ball into play and is called out but the action allows a run to score as in the SF scenario. As a result, the 4 counts are needed to calculate a batter's total trips to the plate. and where:
On-base plus slugging was first popularized in 1984 by John Thorn and Pete Palmer's book, The Hidden Game of Baseball. The New York Times then began carrying the leaders in this statistic in its weekly "By the Numbers" box, a feature that continued for four years. Baseball journalist Peter Gammons used and evangelized the statistic, and other writers and broadcasters picked it up. The popularity of OPS gradually spread, and by 2004 it began appearing on Toppsbaseball cards. OPS was formerly sometimes known as production. For instance, production was included in early versions of Thorn's Total Baseball encyclopedia, and in the Strat-O-Matic computer baseball game. This term has fallen out of use. OPS gained popularity because team average OPS correlates well with team runs scored. However, it is not mathematically legitimate to use this correlation to assume that individual OPS correlates as well with individual runs created, nor is it legitimate to assume that individual OBP correlates well with individual runs created.
An OPS scale
, in his essay titled "The 96 Families of Hitters" uses seven different categories for classification by OPS:
Category
Classification
OPS range
A
Great
.9000 and higher
B
Very good
.8334 to.8999
C
Above average
.7667 to.8333
D
Average
.7000 to.7666
E
Below average
.6334 to.6999
F
Poor
.5667 to.6333
G
Very poor
.5666 and lower
This effectively transforms OPS into a seven-point ordinal scale. Substituting quality labels such as excellent, very good, good, average, fair, poor and very poor for the A–G categories creates a subjective reference for OPS values.
The top four were all left-handed batters. Jimmie Foxx has the highest career OPS for a right-handed batter. The top ten single-season performances in MLB are :
Barry Bonds, 1.4217
Barry Bonds, 1.3807
Babe Ruth, 1.3791
Barry Bonds, 1.3785
Babe Ruth, 1.3586
Babe Ruth, 1.3089
Ted Williams, 1.2875
Barry Bonds, 1.2778
Babe Ruth, 1.2582
Ted Williams, 1.2566
The highest single-season mark for a right-handed hitter was 1.2449 by Rogers Hornsby in, 13th on the all-time list. Since 1935, the highest single-season OPS for a right-hander is 1.2224 by Mark McGwire in, which was 16th all-time.
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 and 125 very good, while an OPS+ of 75 or below is poor. The basic equation for OPS+ is where *lgOBP is the park adjusted OBP of the league and *lgSLG is the park adjusted SLG of the league. A common misconception is that OPS+ closely matches the ratio of a player's OPS to that of their league. In fact, due to the additive nature of the two components in OPS+, a player with an OBP and SLG both 50% better than league average in those metrics will have an OPS+ of 200 while still having an OPS that is only 50% better than the average OPS of the league. It would be a better approximation to say that a player with an OPS+ of 150 produces 50% more runs, in a given set of plate appearances, as a player with an OPS+ of 100.
Leaders in OPS+
Through the end of the 2019 season, the career top twenty leaders in OPS+ were:
The only purely right-handed batters to appear on this list are Hornsby, Foxx, Trout, McGwire, Allen, and Thomas. Mantle is the only switch-hitter in the group. The highest single-season performances were:
* - Fred Dunlap's historic 1884 season came in the Union Association, which some baseball experts consider not to be a true major league. ** - Ross Barnes may have been aided by a rule that made a bunt fair if it first rolled in fair territory. He did not play nearly so well when this rule was removed, although injuries may have been mostly to blame, as his fielding statistics similarly declined. If Dunlap's and Barnes' seasons were to be eliminated from the list, two other Ruth seasons would be on the list. This would also eliminate the only right-handed batter in the list, Barnes.
Criticism
Despite its simple calculation, OPS is a controversial measurement. OPS weighs on-base percentage and slugging percentage equally. However, on-base percentage correlates better with scoring runs. Statistics such as wOBA build on this distinction using linear weights. Additionally, the components of OPS are not typically equal. As a point of reference, the OPS for all of Major League Baseball in 2019 was.758.
