What is OPS+? Definition, Formula, and Example
OPS+ is on-base plus slugging percentage adjusted for park and league context, scaled so that 100 equals league average — a 150 OPS+ means a hitter was 50% better than league average at producing offense.
What is OPS+?
OPS+ is the park- and league-adjusted version of OPS (on-base percentage plus slugging percentage). It strips out the noise that makes raw OPS misleading — Coors Field inflates numbers, pitcher's parks like Petco depress them, and league-wide offense rises and falls year to year. OPS+ scales every hitter to a single index where 100 is exactly league average. A 150 OPS+ means a hitter created 50% more offense than the average MLB bat after adjusting for context; a 75 OPS+ means 25% below average. It's the simplest cross-era comparison stat in baseball: Babe Ruth's career 206 OPS+ and Mike Trout's career 174 OPS+ are directly comparable even though they played a century apart.
How OPS+ is Calculated
The formula used by Baseball Reference is:
OPS+ = 100 × ( OBP / lgOBP + SLG / lgSLG − 1 )
Where lgOBP and lgSLG are league averages adjusted by the player's home park factor. Each component (on-base and slugging) is normalized separately to the league, summed, and then re-centered so that 100 represents the average hitter. Because park factor is applied to the league averages rather than to the player directly, a Rockies hitter must clear a higher bar than a Padres hitter to post the same OPS+.
A subtle point: OPS+ is not literally "OPS divided by league OPS times 100." Treating OBP and SLG as separate ratios is mathematically more honest because they are scaled differently (OBP tops out around .500 in extreme seasons; SLG can exceed 1.000).
Worked Example
Aaron Judge in 2024 hit .322/.458/.701 for a raw OPS of 1.159 in Yankee Stadium (a slight hitter's park). The AL averages were roughly .247 OBP-leading lg average around .315 OBP and .399 SLG. Plugging in: OPS+ ≈ 100 × (.458/.315 + .701/.399 − 1) ≈ 100 × (1.454 + 1.757 − 1) ≈ 221. That's the highest single-season OPS+ since Barry Bonds. For context, Bobby Witt Jr.'s MVP-runner-up 2024 came in around 168 — elite, but in a different tier than Judge that year.
Career benchmarks help calibrate the scale: 100 = average regular, 110-120 = solid everyday player, 130 = All-Star caliber, 150 = MVP candidate, 170+ = inner-circle Hall of Fame season, 200+ = historic.
Why OPS+ Matters
Front offices use OPS+ for one-number offensive comparisons across parks, leagues, and eras when building trade targets and free-agent boards. Hall of Fame voters lean on career OPS+ to weigh hitters from different generations — it's why Edgar Martinez (147) and Larry Walker (141) eventually got in despite playing in extreme park environments. Fantasy and DFS players use single-season OPS+ to identify hitters whose raw lines undersell their true production (a Padres hitter at .790 OPS may be more valuable than a Rockies hitter at .850).
Limitations and Common Misconceptions
OPS+ inherits OPS's flaws. It treats OBP and SLG additively even though OBP is roughly 1.7 times more valuable per point of run-scoring — meaning OPS+ slightly undervalues high-OBP, low-power hitters and overvalues sluggers with mediocre on-base skills. It also ignores baserunning and defense entirely; a 130 OPS+ shortstop and a 130 OPS+ DH have very different total values. For a more accurate offensive index that fixes the OBP/SLG weighting, use wRC+.
Related Terms
In Legends Deck
Hitter overall ratings in Legends Deck use a wRC+/OPS+ blend rather than raw OPS, so a Rockies slugger and a Mariners slugger with identical box-score lines get rated honestly relative to context. That's why a 150 OPS+ card from T-Mobile Park is often more valuable in trade than a 160 OPS+ card from Coors.