OPS stands for on-base plus slugging. It is one number made by adding a hitter’s on-base percentage (OBP) to his slugging percentage (SLG): OPS = OBP + SLG. The first half measures how often a hitter reaches base. The second half measures how much power he hits for. Added together, they give the quickest single-number summary of a hitter’s season that most fans, broadcasts and front offices use.
That is the whole definition. Everything else in this article is about reading the number properly: where the two halves come from, how to calculate OPS from a raw batting line, what counts as good, and what the stat quietly leaves out.
Why OPS exists: the problem with batting average
For most of baseball history, hitters were judged by batting average — hits divided by at-bats. Batting average has two blind spots. It treats every hit as equal, so a bloop single and a 450-foot home run count the same. And it ignores walks completely, even though a walk puts a runner on base exactly the way a single does.
OPS was built to fix both problems at once. On-base percentage counts walks and hit-by-pitches, not just hits, so patient hitters stop being undervalued. Slugging percentage weights hits by how many bases they are worth, so power stops being invisible. Neither half is new or exotic — both sit in MLB’s official glossary — but adding them together produces a number that tracks run scoring far better than batting average ever did.
The first ingredient: on-base percentage (OBP)
On-base percentage is the rate at which a hitter reaches base by hit, walk or hit-by-pitch. MLB’s glossary defines it with this formula:
OBP = (H + BB + HBP) ÷ (AB + BB + HBP + SF)
- H — hits
- BB — walks (bases on balls)
- HBP — times hit by a pitch
- AB — at-bats
- SF — sacrifice flies
Two details in that formula trip people up. Reaching base on an error or a fielder’s choice does not count — the hitter got on, but not by one of the credited routes, so his OBP gets no help from it. And sacrifice bunts are left out of the denominator entirely, while sacrifice flies are included. That is why the bottom of the formula is not simply “plate appearances,” even though it is close.
Despite the name, OBP is written as a decimal, not a percentage. A .340 OBP means the hitter reached base in about 34 percent of the trips counted by the formula. League-average OBP in recent seasons has sat around .310 to .320.
The second ingredient: slugging percentage (SLG)
Slugging percentage measures power: the average number of total bases a hitter produces per at-bat. MLB’s glossary defines it as:
SLG = Total Bases ÷ At-Bats
Total bases are built from the hit types: a single is worth 1 base, a double 2, a triple 3 and a home run 4. So total bases can also be written as:
TB = 1B + (2 × 2B) + (3 × 3B) + (4 × HR)
This is what separates slugging from batting average. Two hitters can both bat .300, but if one hits singles and the other hits doubles and home runs, the second hitter’s slugging percentage will be far higher — correctly, because his hits move runners further and score more runs. A slugging percentage of .500 means the hitter averaged half a total base per at-bat — one full base for every two trips. Because a home run alone is worth four bases in a single at-bat, slugging can rise well above 1.000 in a short stretch, though full-season marks usually land between .350 and .550.
The worked example: Aaron Judge, 2024
Most explanations of OPS stop at adding two published decimals. Here is the full calculation from the raw batting line, so you can see where every number comes from. Aaron Judge’s 2024 season with the New York Yankees:
| Stat | Value |
|---|---|
| At-bats (AB) | 559 |
| Hits (H) | 180 |
| Doubles (2B) | 36 |
| Triples (3B) | 1 |
| Home runs (HR) | 58 |
| Walks (BB) | 133 |
| Hit by pitch (HBP) | 9 |
| Sacrifice flies (SF) | 2 |
Step 1 — total bases. Judge’s 180 hits break down into 85 singles (180 − 36 − 1 − 58), 36 doubles, 1 triple and 58 home runs:
TB = 85 + (2 × 36) + (3 × 1) + (4 × 58) = 85 + 72 + 3 + 232 = 392 total bases
Step 2 — slugging percentage.
SLG = 392 ÷ 559 = .701
Step 3 — on-base percentage.
OBP = (180 + 133 + 9) ÷ (559 + 133 + 9 + 2) = 322 ÷ 703 = .458
Step 4 — add them.
OPS = .458 + .701 = 1.159
That matches Judge’s published 2024 line exactly — a .458 OBP, a .701 SLG and a 1.159 OPS, the best full-season OPS in the majors that year. Note what the number is saying: Judge reached base in nearly 46 percent of his counted trips to the plate and averaged more than seven-tenths of a base per at-bat. OPS rewards him for both at once, which is precisely what it was designed to do.
What is a good OPS? The scale
OPS has no official grading scale — MLB’s glossary defines the stat but does not grade it. The bands below are the convention used across most coverage, so treat them as a rule of thumb, not a law:
| OPS | Reading |
|---|---|
| Below .650 | Poor — a hitter usually in the lineup for his glove |
| .650 to .700 | Below average |
| Around .700 to .730 | Roughly league average |
| .800 | Good — a solid middle-of-the-order hitter |
| .900 | Great — among the best hitters in the league that season |
| 1.000 and above | Elite — an MVP-calibre season; only a handful of hitters get there |
Context matters because the league average moves. The major leagues as a whole posted a .711 OPS in 2024, against .758 in the high-offence season of 2019. So a .760 OPS was slightly above average in 2024 but would have been dead average in 2019. This is also why claims you may see elsewhere that “the average OPS is around .750” should be read with suspicion — that figure describes a particular high-scoring era, not the modern norm.
One more scale worth knowing: Bill James, the writer who did much to popularise modern baseball analysis, sorted OPS into seven families running from “great” (.9000 and up) down through “average” (.7000 to .7666) to “very poor” (.5666 and below). The labels differ from the table above, which is the point — every OPS scale is someone’s convention, and the honest ones say so.
The record book: the highest OPS marks ever
Numbers mean more with the ceiling in view. The highest career OPS in major league history belongs to Babe Ruth, at 1.164 — a mark built on a .474 on-base percentage and a .690 slugging percentage across 22 seasons. Ted Williams sits second at 1.116 and Lou Gehrig third at 1.080; Barry Bonds, fourth at 1.051, is the only player from the modern era above 1.050.
The single-season record is Bonds again, and it is not close: 1.422 in 2004, a season in which he walked 232 times and still slugged .812. Ruth’s 1.382 from 1920 is second. Set those against the scale above and Judge’s 1.159 in 2024 lands in its proper place — an enormous season that still sits more than two-tenths below the record, which is exactly how far out on the edge Bonds’s 2004 was.
OPS+: the adjusted version
Raw OPS never adjusts for context. A .850 OPS in a hitter-friendly park in a high-scoring year is not the same achievement as a .850 in a pitcher’s park in a dead-ball season. OPS+ fixes that. As MLB’s glossary puts it, OPS+ takes a player’s on-base plus slugging and normalises the number across the entire league, accounting for external factors such as ballparks, then adjusts it so that 100 is exactly league average.
The reading is simple: an OPS+ of 150 means the hitter produced at a level 50 percent better than the league average, after park and league adjustments; an OPS+ of 80 means 20 percent below. Use raw OPS for a quick look within one season. Use OPS+ when you compare players across different seasons, eras or home parks.
What OPS does not capture
OPS is a hitting stat, and only a hitting stat. Keep its blind spots in mind:
- Defence. A shortstop or catcher who hits .720 while playing a premium defensive position can be more valuable than a designated hitter at .800. OPS sees none of that.
- Baserunning. Stolen bases, extra bases taken on balls in play and avoiding double plays all add runs. None of them appear in OBP or SLG. (Judge’s example partner in 2024, Shohei Ohtani, stole 59 bases on top of his 1.036 OPS — value OPS does not count.)
- Position. Raw OPS compares every hitter against the same bar, even though offence is scarcer at catcher and shortstop than at first base or DH.
- Equal weighting. OPS adds OBP and SLG one-for-one, but analysts have long noted that a point of OBP is worth more runs than a point of SLG. More advanced stats such as wOBA exist largely to correct that weighting.
- Park and era. That is what OPS+ is for, as covered above.
None of this makes OPS a bad stat. It makes it a first look, not a final verdict.
A short history
On-base plus slugging was first popularised in 1984 by John Thorn and Pete Palmer in their book The Hidden Game of Baseball, which presented it as a simple way to combine the two skills that drive scoring. The New York Times began printing OPS leaders in its weekly numbers column, broadcasters picked it up, and by 2004 the stat had reached the back of Topps baseball cards. It was once also called “production,” a name that has fallen out of use. Its rise tracked the growth of sabermetrics — the statistical analysis of baseball — and it remains the most widely quoted single hitting number in the game.
Frequently asked questions
Is OPS a percentage? No. It is the sum of two percentages, so it behaves like neither. That is why it can exceed 1.000 — the theoretical maximum is 5.000 (a 1.000 OBP plus a 4.000 SLG).
What is a good OPS in MLB today? Around .800 is good, .900 is great and 1.000 is elite, against a league average near .710 in recent seasons. Always compare with the average of the season in question.
OPS or OPS+ — which should I use? OPS for a quick read on hitters in the same season. OPS+ for comparisons across seasons, eras or ballparks, because it is adjusted and scaled to 100.
Can OPS be used for pitchers? Yes, in reverse: “OPS against” is the combined OPS of the hitters a pitcher has faced. Lower is better.
Why not just use batting average? Because batting average ignores walks and counts a single and a home run as equals. OPS fixes both flaws in one step, which is why it tracks run scoring so much better.
Who has the highest OPS of all time? Babe Ruth, at 1.164 for his career. The highest single season is Barry Bonds’s 1.422 in 2004. Both marks are covered in the record-book section above.
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