OPS in Baseball: What On-Base Plus Slugging Tells You

Barry Bonds drew 232 walks in 2004, and 120 of them were intentional. Add his .609 on-base percentage to his .812 slugging percentage and the result is 1.422, the highest OPS any American League or National League hitter has recorded. That sum, on-base plus slugging, is the whole of the statistic. OPS takes the two halves of a hitter's production, how often he avoids making an out and how many bases his hits are worth, and puts them in one number.

So the short answer to what OPS in baseball means is this: OPS equals on-base percentage plus slugging percentage. Major League Baseball shows it on its official stat pages, every broadcast puts it on screen, and it is written to three decimal places like a batting average, so an .850 OPS is said "eight-fifty." A regular MLB hitter usually lands somewhere between .700 and .750, .800 is good, .900 is All-Star territory and 1.000 is an MVP-level season. The rest of this page explains the arithmetic, why it works better than it ought to, where it goes wrong and what replaced it among analysts.

What OPS stands for: on-base plus slugging in one figure

Each half answers a different question. On-base percentage asks how often a hitter got on base by his own doing, through a hit, a walk or a hit by pitch. Slugging percentage asks how many bases he averaged per official at-bat, counting a single as one, a double as two, a triple as three and a home run as four. A hitter can be excellent at one and ordinary at the other, which is exactly why neither stands alone.

Think of two familiar types. The leadoff man who takes pitches, walks 90 times and slaps singles has a high on-base percentage and modest slugging. The free-swinging power hitter who strikes out 180 times and walks rarely has the reverse profile. Batting average treats them as near-identical if their hit totals line up. OPS does not, because it rewards the walks of the first and the extra bases of the second on the same scale.

The pieces are covered in depth on their own pages: our guide to on-base percentage in baseball goes through what counts as reaching base and what does not, and the companion page on slugging percentage walks through total bases. OPS borrows both definitions without changing them.

Why the name tells you the formula

Most baseball statistics carry names that hide how they are built. Earned run average needs a paragraph. WAR needs a book. OPS is literally its own formula spelled out: on-base, plus, slugging. A fan who knows those two numbers can compute it in their head during a pitching change, which goes a long way toward explaining why it spread from analysts to broadcasts faster than anything else from the statistical revolution of the 1980s and 1990s.

One clarification on the word "percentage." Neither half is a percentage in the strict sense. On-base percentage is a rate between .000 and 1.000. Slugging is bases per at-bat and can run as high as 4.000. Baseball kept the old names, and OPS inherited the habit of three-decimal notation from them.

How OPS is calculated from a raw stat line

Start from a season line and work out each half on its own. There is no shortcut that skips the two separate calculations, because the denominators differ.

Here is an invented but realistic season for a middle-of-the-order hitter: 600 plate appearances, 520 at-bats, 145 hits (88 singles, 30 doubles, 2 triples and 25 home runs), 65 walks, 8 hit by pitches and 7 sacrifice flies.

Step	What goes in	Result
Times on base	145 hits + 65 walks + 8 hit by pitch	218
On-base denominator	520 at-bats + 65 walks + 8 hit by pitch + 7 sacrifice flies	600
On-base percentage	218 divided by 600	.363
Total bases	88 + (30 × 2) + (2 × 3) + (25 × 4)	254
Slugging percentage	254 divided by 520	.488
OPS	.3633 + .4885, then rounded	.852

The batting average for the same line is .279, 145 divided by 520. Written as a slash line it reads .279/.363/.488, and the OPS of .852 is the sum of the last two numbers.

Add before rounding

A small trap. If you round each half first and then add, you can be off by a point. In the example, .363 plus .488 is .851, but the unrounded figures, .36333 and .48846, sum to .85179, which rounds to .852. Official sources add the full-precision numbers. A one-point gap between a figure you computed and the one on a stat site is almost always this.

How OPS runs past 1.000

The ceiling is 5.000. A hitter who reached base every time (an on-base percentage of 1.000) and homered in every at-bat (a slugging percentage of 4.000) would post it. Nobody gets anywhere near that over a season, but the arithmetic means 1.000 is not a cap the way it is for on-base percentage. A hitter crosses it with, say, a .420 on-base percentage and a .580 slugging percentage. That is rare air, and the seasons that clear 1.000 by a wide margin are mostly Babe Ruth, Ted Williams and Bonds.

The floor is .000, which happens only to a hitter with no hits, no walks and no hit by pitches over his plate appearances. Late-season call-ups with a handful of plate appearances, and position players who come up only once or twice, manage it in small samples every year.

1. 1Count times on baseAdd hits, walks and hit by pitches. Reaching on an error or a fielder's choice does not count.
2. 2Build the on-base denominatorAdd at-bats, walks, hit by pitches and sacrifice flies.
3. 3Divide for on-base percentageKeep the full decimal rather than rounding to three places.
4. 4Count total basesOne for a single, two for a double, three for a triple, four for a home run.
5. 5Divide for sluggingTotal bases over at-bats only, with walks and sacrifices left out.
6. 6Add and roundSum the two unrounded rates, then round to three decimal places.

The order of operations official sources follow. Sacrifice bunts appear in neither denominator; sacrifice flies count only toward on-base percentage.

What a good OPS is in MLB, rung by rung

Fans use a rough ladder, and it holds up reasonably well across recent decades. It is a convention, not an official scale, and every step on it slides with league scoring.

OPS	What it usually means for an everyday MLB hitter
1.000 or higher	MVP-level season; a handful of hitters at most reach it in a typical year
.900 to .999	All-Star bat, one of the best hitters in his league
.800 to .899	Good, a lineup piece a contender builds around
.700 to .799	Around league average to a little above, depending on the year
.650 to .699	Below average; acceptable only with strong defense at a hard position
Under .650	Weak; an everyday job at this level rests entirely on the glove

The league-average figure is the anchor, and it moves more than most fans realize. In 1968, the Year of the Pitcher, the two major leagues combined for an OPS of .639. In 2000 they combined for .782. A .750 hitter was comfortably above average in the first season and a little below it in the second.

American and National Leagues combined, shown in points, so 734 is an OPS of .734. Selected seasons chosen to show high and low scoring years, not a continuous series.

Show the numbers

League-wide OPS in selected MLB seasons

Item	League OPS
1930	790
1968	639
2000	782
2014	700
2019	758
2023	734

Position changes the bar

A .720 OPS from a shortstop who saves runs in the field is a fine season. The same .720 from a first baseman or a designated hitter is a problem, because those positions carry little defensive value and a team expects the bat to make up for it. Catchers and shortstops as groups post lower OPS than first basemen and corner outfielders every season. The ladder above is for hitters in general; inside a front office the comparison is always against the position.

A note on sample size

A month of OPS tells you very little. A hitter can post 1.100 across 80 plate appearances in April on a run of soft-contact singles and fly balls that carried, then settle at .780. Most analysts want something like a full season before they treat an OPS as a description of the hitter rather than of his luck, a point developed in our explainer on BABIP and what it says about luck.

Why two rates with different denominators get added anyway

The arithmetic is untidy and every analyst knows it. On-base percentage divides by something close to plate appearances. Slugging divides by at-bats, which leaves out walks, hit by pitches and sacrifices. Adding two fractions with different bottoms is not something a math teacher would accept, and the result is not a rate of anything. There is no event of which OPS is the frequency.

It works anyway, and the reason is practical. Runs come from two things: putting men on base and moving them around. On-base percentage measures the first. Slugging measures the second, because extra-base hits advance runners further than singles and the home run scores everyone. A statistic that captures both will line up with run scoring, whatever its arithmetic looks like.

Line up the 30 teams in almost any modern season by OPS, then by runs scored, and the two orders come out close to identical. Do the same with batting average and the order wobbles noticeably, because a team that walks a lot or hits for power outscores its average. Researchers who ran these comparisons across many seasons of team data found OPS tracked runs far more closely than average did, and nearly as closely as statistics with much more complicated formulas. That is the whole case for OPS. It is a good-enough approximation that anyone can compute.

The denominator problem in practice

In a typical season the gap between plate appearances and at-bats is around 10 percent of a hitter's trips to the plate, mostly walks. For a hitter who walks a great deal, the gap is larger, and his slugging percentage is computed over noticeably fewer trips than his on-base percentage. The consequence is slight but real: a walk raises a hitter's on-base percentage while leaving his slugging untouched in its numerator and shrinking nothing in its denominator, so the walk-heavy hitter's OPS is built on two slightly different samples of his season. Nobody has found this distortion large enough to matter for ranking regular hitters. It matters to people who want a statistic to mean something precise, which is part of why weighted on-base average was built.

OPS against batting average: two .280 hitters 150 points apart

Batting average counts hits per at-bat and stops there. It cannot see a walk and it treats a home run as identical to a bloop single. OPS sees both. The quickest way to understand the difference is to put two hitters with the same average side by side.

Hitter A bats .280 with almost no walks and mostly singles. Hitter B also bats .280, draws plenty of walks and hits for power. Their lines might look like this:

	Average	On-base	Slugging	OPS
Hitter A	.280	.320	.400	.720
Hitter B	.280	.380	.490	.870
Gap	.000	.060	.090	.150
What the gap is	Identical hits per at-bat	Roughly 36 extra trips on base over 600 plate appearances	Extra-base hits	Walks plus power

• Hitter A
• Hitter B

Batting average280280

On-base percentage320380

Slugging percentage400490

OPS720870

Invented lines for illustration, shown in points, so 380 is .380. Both hitters have the same batting average; the difference sits entirely in walks and extra-base hits.

Show the numbers

Two .280 hitters, split into the parts of OPS

Item	Hitter A	Hitter B
Batting average	280	280
On-base percentage	320	380
Slugging percentage	400	490
OPS	720	870

On batting average alone, the two hitters are equal. On OPS, Hitter B is a good everyday bat and Hitter A is around average. Over a full season of 600 plate appearances, a .060 gap in on-base percentage is about 36 more times on base, and every one of those trips is a chance for the hitters behind him to drive a run in. The slugging gap of .090 over roughly 520 at-bats is close to 47 extra total bases, the equivalent of about two dozen doubles turned into home runs.

What batting average still does well

The average is not useless. It is the best single measure of how often a hitter puts the ball in play safely, and that skill is real. It also feeds into both halves of OPS, since every hit counts toward on-base percentage and toward slugging. The fault is in asking it to rank hitters on its own. The full case for and against the old statistic is on our page about batting average in baseball.

A last practical point. Batting titles are still awarded on average, the Triple Crown still uses it and box scores still lead with it. OPS has won the argument among analysts and on broadcast graphics without displacing average from the record book.

The slash line: reading .280/.360/.500 at a glance

Broadcasts and baseball cards print three numbers separated by slashes: batting average, on-base percentage and slugging percentage, in that order. OPS is the sum of the last two, and a fan who reads the slash line well rarely needs OPS spelled out.

Take .280/.360/.500. Add the last two and the OPS is .860, a good hitter. But the slash line says more than its sum, and that is the reason it survives beside OPS on every screen.

The first gap: on-base minus average

The distance between the first and second numbers, here .080, is mostly walks and hit by pitches. A gap under about .050 marks a free swinger. A gap near .100 or more marks a patient hitter who works counts and is pitched around. Two hitters with identical OPS figures can sit on opposite ends of this scale.

The second gap: slugging minus average

Subtract average from slugging and you get isolated power, here .220. It strips the singles out and leaves only the extra bases. Isolated power of .150 is around a league norm in recent seasons; .250 belongs to a genuine slugger. Like OPS itself, it is simple enough to work out in a commercial break.

Same OPS, different hitters

Slash line	OPS	What it describes
.310/.390/.470	.860	High average, patient, gap power
.240/.350/.510	.860	Low average, many walks, home-run power
.290/.320/.540	.860	Free swinger who hits for power
.260/.400/.460	.860	Walk-heavy table setter with modest power

Four hitters, one OPS, four different roles in a lineup. A manager building a batting order cares about the shape as well as the total, which is why the slash line, and not OPS alone, appears beside the name when a hitter steps in. The decisions that follow from the shape are covered in our guide to the baseball batting order.

The known flaw in the addition: on-base is worth more

OPS weights a point of on-base percentage exactly the same as a point of slugging. Run-scoring research says it should not.

Avoiding an out is the scarcest thing in baseball. A team gets 27 outs, and every out made ends one possible scoring chance. A walk does not advance runners as far as a double, but it does not use up an out, and the team keeps batting. When analysts estimated how many runs each point of each statistic produced, using regression on team seasons and run-expectancy tables built from play-by-play data, a point of on-base percentage came out worth somewhere around one and a half to twice as much as a point of slugging. The commonly quoted figure is about 1.8.

What the error does to rankings

Because slugging is the larger number and has a wider spread between hitters, OPS ends up driven mostly by power. Compare a .400/.400 hitter with a .300/.500 hitter. Both post an .800 OPS. The first reaches base 40 percent of the time and should produce more runs, by most run models clearly more. OPS calls them equal.

Real hitters are rarely that extreme, so the distortion is usually a matter of a few places in a ranking rather than a wholesale inversion. It is largest at the edges: walk-heavy, low-power hitters are understated and free-swinging sluggers are flattered.

The fixes people proposed

In 2003 the writer Aaron Gleeman suggested Gross Production Average, which multiplies on-base percentage by 1.8, adds slugging and divides by four so the result reads on the batting-average scale. It corrected the weighting and never caught on. Others proposed simple ratios. The lasting answer came from building a statistic from the ground up rather than patching OPS, which is where weighted on-base average comes in, later on this page.

The fix that the broadcasts never adopted tells you something. OPS stayed because it was easy, and a corrected version that required a multiplication lost the one advantage that made the original spread.

What OPS ignores, and the gap OPS+ was built to close

OPS is a batting statistic and only a batting statistic. Several things that decide a player's value never enter it.

Baserunning. A hitter who goes from first to third on a single, steals 30 bases and rarely grounds into a double play adds runs that OPS cannot see. Stolen bases and caught stealing are absent from both halves.

Defense. A center fielder and a designated hitter with the same OPS are not equally valuable, because one also saves runs in the field. Fielding metrics such as Defensive Runs Saved, explained in our page on how DRS rates fielders, are built to capture the part OPS leaves out.

Position. As covered above, the offensive bar for a catcher is lower than for a first baseman.

Home ballpark. Coors Field in Denver, a mile above sea level, inflates offense; a few parks on the coasts suppress it. A Rockies hitter's raw OPS overstates his bat. Our explainer on park factors in baseball covers how much a park can move a number.

Era. A .800 OPS in 1968 was a star. In 2000 it was a solid regular.

How OPS+ corrects for park and era

OPS+, the version Baseball-Reference publishes, takes the hitter's on-base percentage and divides it by the league's, does the same with slugging, adds the two ratios and subtracts one, then multiplies by 100. The league figures are adjusted for the hitter's home park. The result is scaled so 100 is exactly league average. An OPS+ of 150 means the hitter was about 50 percent better than average once park and league are accounted for; 80 means 20 percent worse.

Notice what that formula does to the weighting problem. Because each half is divided by its own league average before adding, and league on-base percentage is smaller than league slugging, a point of on-base percentage ends up counting for more in OPS+ than a point of slugging does. The adjustment partly repairs the flaw of the raw sum. The formula and its quirks are worked through in our longer piece on OPS+ and adjusted OPS.

OPS+ still leaves out baserunning, defense and position. Those land in wins above replacement, which takes a park-and-era-adjusted batting measure and adds the rest; our explainer on what WAR actually measures covers how the pieces combine.

OPS allowed: the same number turned on pitchers and on splits

Turn the statistic around and it judges pitchers. OPS allowed, sometimes written as opponents' OPS, is the on-base percentage plus slugging percentage of every batter a pitcher faced. A pitcher who holds hitters to a .600 OPS is turning the average lineup into a team of light-hitting middle infielders. One who allows .850 is turning it into a team of All-Stars.

It has an advantage over earned run average for some purposes. ERA depends on sequencing, on when the walks and hits happened, on the defense behind the pitcher and on how the bullpen handled the runners he left on base. OPS allowed looks only at what happened in each plate appearance against him, so it is steadier from season to season, though it still includes hits on balls in play that the defense might have turned into outs. For the pitcher's other headline numbers, our guide to WHIP in baseball covers walks and hits per inning, which is effectively the on-base half of OPS allowed with home runs counted the same as singles.

Left-right splits

The most common use of OPS on broadcasts is for splits. A hitter's OPS against right-handed pitchers and against left-handers, or a pitcher's OPS allowed to right-handed and left-handed batters, shows the platoon advantage in one comparison. A left-handed hitter with a .880 OPS against right-handers and .640 against left-handers is a classic platoon bat. A reliever whose OPS allowed to left-handed hitters is 200 points lower than to right-handers was once the definition of a lefty specialist, before the three-batter minimum of 2020 made that role harder to use. The managerial side of these numbers is in our page on the platoon in baseball.

Splits are where sample size bites hardest. A hitter might get 150 plate appearances against left-handed pitching in a season, and an OPS over that many trips can swing by 100 points on a handful of balls in play. Front offices weigh several seasons of split data before trusting the pattern.

Home, road and month

The same split logic runs through every situational table on a stat site: OPS at home and on the road, by month, with runners on, by count. Most of these splits are noise over one season. Home and road splits are the exception worth reading, because they show a park effect in the raw form before OPS+ smooths it.

What came after OPS: wOBA and wRC+ in outline

The statistic analysts use in place of OPS today is weighted on-base average, wOBA, introduced by Tom Tango in The Book: Playing the Percentages in Baseball, written with Mitchel Lichtman and Andrew Dolphin and published in the mid-2000s. Its starting point is the flaw described above. Instead of adding two rates, it gives every way of reaching base its own weight, set by how many runs that event is worth on average.

A walk gets a smaller weight than a single. A single gets a smaller weight than a double, and so on to the home run. The weights are recalculated for each season from the run environment, so they change slightly from year to year. Unintentional walks count, intentional walks are left out, and the total is divided by a figure close to plate appearances. The result is then scaled so league-average wOBA matches league-average on-base percentage, which lets fans read it on a familiar scale: around .320 is average, .370 is very good, .400 is elite.

The structural change matters more than any single weight. In OPS a home run is worth four times a single on the slugging side, which overstates it, and a walk is worth nothing on that side, which understates it. In wOBA the home run is worth a little more than twice a single and the walk somewhat less than a single, ratios that come from actual run scoring.

wRC+: the OPS+ of the new measure

Weighted runs created plus, published by FanGraphs, does to wOBA what OPS+ does to OPS. It converts wOBA into runs, adjusts for park and league, and sets 100 as average. A wRC+ of 140 means 40 percent better than average. Among analysts it has become the default single number for a hitter's batting, with OPS+ close behind and raw OPS used for quick conversation.

1. 1Batting averageHits per at-bat. Blind to walks and treats every hit alike.
2. 2On-base and sluggingOne counts walks, the other counts extra bases. Each still misses what the other sees.
3. 3OPSAdds the two. Tracks team runs well but weights on-base and slugging equally.
4. 4OPS+Adjusts OPS for park and league and sets 100 as average.
5. 5wOBAWeights each way of reaching base by the runs it is worth.
6. 6wRC+Turns wOBA into runs, adjusts for park and league, and sets 100 as average.

A simplified lineage. Each step kept the earlier statistic's purpose and corrected one of its blind spots; none of them measures defense or baserunning beyond what is noted.

Why OPS is still on the scoreboard

wOBA is better and nobody can compute it in their head. The weights change each season, intentional walks have to be pulled out, and the scaling step is invisible to a fan. OPS needs only the two numbers already on the screen. For a broadcaster with eight seconds to say whether a hitter is good, that is decisive. And at the level of ranking regular hitters over a full season, OPS and wOBA agree far more often than they disagree. The simpler statistic is wrong in known directions by known amounts, which is a respectable thing for a statistic to be.

The record book: Gibson's 1.177, Ruth's 1.164 and Bonds's 2004

For most of the last century Babe Ruth's career OPS sat alone at the top of the list. That changed in May 2024, when Major League Baseball incorporated statistics from seven Negro Leagues between 1920 and 1948 into its official record, following the work of a research committee and the Seamheads database. Josh Gibson, the Homestead Grays and Pittsburgh Crawfords catcher, became the career leader in OPS, slugging percentage and batting average.

Hitter	Career OPS	Career span
Josh Gibson	1.177	1930s and 1940s, Negro Leagues
Babe Ruth	1.164	1914 to 1935
Ted Williams	1.116	1939 to 1960, with years lost to military service
Lou Gehrig	1.080	1923 to 1939
Barry Bonds	1.051	1986 to 2007
Jimmie Foxx	1.038	1925 to 1945

That is a selection from the top of the list, not a numbered ranking, because the integrated record also carries other Negro Leagues hitters with high marks over shorter documented careers, and active hitters can climb it. The figures are career totals through the 2025 season; for retired players they are fixed, while an active hitter's total moves every season he plays.

Single seasons

The single-season list has a similar shape. Gibson's 1.474 in 1937 is the official record. It came over a Negro Leagues season of far fewer documented games than a modern 162-game schedule, a point worth keeping in mind when comparing it with anything else on the list, and other short Negro Leagues seasons, Gibson's own among them, also sit high on the integrated list. Among American League and National League seasons, Bonds's 1.422 in 2004 is the highest, followed by his 1.381 in 2002, essentially level with Ruth's 1.379 in 1920 and Bonds's own 2001 season.

• 1.47Josh Gibson, 1937
• 1.42Barry Bonds, 2004
• 1.38Barry Bonds, 2002
• 1.38Babe Ruth, 1920

Official MLB figures. Gibson's 1937 season covers far fewer documented games than a modern schedule, and other Negro Leagues seasons not shown here also rank high on the integrated list. The three Bonds and Ruth figures are the top American League or National League seasons.

Bonds's seasons from 2001 to 2004 were played under the cloud of the era's performance-enhancing drug investigations, and that history is part of how many fans read his line. The figures stand in the official record, and MLB has never removed them.

Who reaches 1.000 now

Seasons above 1.000 are scarce in the modern game. A league as a whole posting an OPS in the low .700s means a hitter at 1.000 is roughly 35 to 40 percent better than average before park adjustment. Most seasons produce one or two qualified hitters at that level, sometimes none in a league, which is why 1.000 has become shorthand for an MVP campaign.

Where OPS came from: Rickey, Roth, Thorn and Palmer

The statistic is older than most fans assume. In August 1954, Life magazine published an article under Branch Rickey's name, "Goodby to Some Old Baseball Ideas," built on work by Allan Roth, the Brooklyn Dodgers' statistician and the first full-time statistician employed by a major league club. Rickey argued that batting average was a poor guide to a hitter and proposed an efficiency formula that added on-base average to a measure of extra-base power. It was not OPS in its modern form, but the central idea was there: getting on base and hitting for power belong in the same measurement, and the two should be added.

The article was widely read and largely ignored. Front offices and writers kept quoting average, home runs and runs batted in.

The Hidden Game of Baseball, 1984

Three decades later, John Thorn and Pete Palmer published The Hidden Game of Baseball. Among much else, the book presented a measure the authors called Production, on-base percentage plus slugging percentage, and showed that it tracked team run scoring about as well as far more complicated formulas. They also introduced a normalized version, adjusted for park and league with 100 as average, which became OPS+. Palmer's work went into Total Baseball, the encyclopedia that brought these figures to a wide readership.

Over the 1990s the sum, now widely called OPS, spread through the analytical community on the early internet and in Bill James's circle. Baseball Prospectus, founded in the mid-1990s, used it heavily. By the early 2000s the 2002 Oakland Athletics and the book about them, Moneyball, had made on-base percentage a mainstream topic, and OPS rode along.

1. 11954Branch Rickey and Allan Roth argue in Life magazine that on-base average and power should be measured together.
2. 21984John Thorn and Pete Palmer publish The Hidden Game of Baseball, presenting on-base plus slugging as Production and its normalized form.
3. 31990sAnalysts and early baseball websites adopt the sum under the name OPS.
4. 4Early 2000sOn-base percentage becomes a mainstream subject after Moneyball, and OPS appears on stat pages and broadcast graphics.
5. 52010s onwardOPS is a standard broadcast figure while analysts move on to wOBA and wRC+.

A sequence of documented milestones. Dates for broadcast adoption are approximate because no single network or season can be said to have introduced it.

Why it stuck

The case for OPS was never that it was right. Thorn and Palmer, and every serious analyst since, knew about the equal-weighting problem. The case was that it was nearly right and easy. A statistic that gets a fan 90 percent of the way to the truth with one addition beats a perfect one that nobody will compute, at least on a scoreboard. MLB's own stat pages list it beside the traditional figures, and on broadcasts it has largely replaced the old practice of quoting a hitter's average and home runs as the measure of his season.

For the rest of the sport's numbers and the teams that post them, the baseball section of the site collects our other guides.