Batting Average in Baseball: The Formula, .300 and .400

Batting average in baseball is a hitter's hits divided by his official at-bats, carried to three decimal places. Major League Baseball sets the method in Rule 9.21(b) of the Official Baseball Rules. Walks, hit by pitches and sacrifices are not at-bats, so they neither raise the number nor lower it. A .300 average, three hits in every ten at-bats, has marked out a fine hitter for well over a century. The league as a whole has hit in the .240s in most recent seasons, and .200 is the floor known as the Mendoza Line.

The division can turn on a single hit. On the morning of September 28, 1941, Ted Williams had 179 hits in 448 at-bats. Divide one by the other and the answer is .39955, which the record book would have rounded up to .400, and his manager offered to let him sit out the season-ending doubleheader in Philadelphia and keep it. Williams played both games at Shibe Park, went 6-for-8 and finished at .406. Nobody in the American or National League has hit .400 since.

What batting average is and how the number is read

Hits on top, at-bats underneath. A player who goes 1-for-4 on a Tuesday night has hit .250 for the game. Two hits in five at-bats is .400. Across a season the same sum is run on the totals, so Williams's 185 hits in 456 at-bats come to .40570, which rounds to the .406 printed in every record book since.

The convention is three decimal places, and the leading zero is dropped. Nobody in a ballpark says "zero point three." A hitter is "batting three hundred," or "hitting two-eighty," and the gaps between hitters are counted in points: a man at .285 is fifteen points ahead of one at .270. The expression "batting a thousand" comes from the same habit. An average of 1.000 means a hit in every at-bat, and it only ever exists in the first days of April or in the line of a pitcher who came to the plate once in his life.

Because it is a ratio of small whole numbers, the figure is jumpy early and stubborn late. On the second day of a season one hit can move an average by 250 points. By September a regular has around 550 at-bats behind him, and a single hit is worth less than two points. Fans who watch a scoreboard average barely twitch through a three-hit night in August are watching arithmetic, not indifference.

1. 1Count the hitsAdd up singles, doubles, triples and home runs. Each counts once. Williams had 185.
2. 2Count the at-batsTake plate appearances and remove walks, hit by pitches, sacrifices and interference awards. Williams had 456.
3. 3DivideHits divided by at-bats. 185 divided by 456 is 0.40570.
4. 4RoundCarry the result to three decimal places and drop the leading zero. The season is recorded as .406.
5. 5Say itRead the three digits as a whole number. Williams hit "four-oh-six."

The method in Rule 9.21(b) of the Official Baseball Rules, using Ted Williams's 1941 season as the example.

The distance between a good hitter and an ordinary one is smaller than the three digits make it look. Take 500 at-bats. A .250 hitter has 125 hits and a .300 hitter has 150. Twenty-five hits, spread over a season that runs about 26 weeks, is one extra hit a week. The 1988 film Bull Durham gave that sum to its veteran catcher as a speech about the difference between the minors and Yankee Stadium, and the arithmetic in it is sound.

Rounding occasionally decides things. Batting races that look tied at three places are settled by carrying the division further, and the 1941 story turns on the fact that .39955 would have gone into the books as .400 without anyone blinking.

What counts as an at-bat and what does not

The whole character of the statistic comes from its denominator. A plate appearance is any completed trip to the plate. An at-bat is a plate appearance that the rules have decided to hold against the hitter if he fails, and Rule 9.02(a)(1) lists the trips that are excused: a sacrifice bunt or sacrifice fly, a base on balls, a hit by pitch, and an award of first base for interference or obstruction.

What happens	At-bat charged	Hit credited	Effect on the average
Single, double, triple or home run	Yes	Yes	Goes up
Strikeout, ground out or fly out	Yes	No	Goes down
Reaches on a fielding error	Yes	No	Goes down
Reaches on a fielder's choice	Yes	No	Goes down
Reaches on a dropped third strike	Yes	No	Goes down
Walk, intentional or not	No	No	Unchanged
Hit by a pitch	No	No	Unchanged
Sacrifice bunt	No	No	Unchanged
Sacrifice fly	No	No	Unchanged
Catcher's interference	No	No	Unchanged

The logic behind the exemptions is older than anyone now alive. A walk was regarded as the pitcher's failure, not the batter's achievement, so it was scrubbed from the record on both sides. A sacrifice was a deliberate out made for the team, and charging it seemed unfair. Whatever one thinks of the reasoning, the result is that a hitter can come to the plate five times, walk twice, get hit once, and finish the night 0-for-2.

Reaching base without a hit

The three rows that surprise people are the ones where the batter is standing on first and his average has dropped. An error means the scorer has judged that ordinary effort would have retired him, so he is charged with an at-bat and no hit. A fielder's choice means the defense could have thrown him out and chose to get another runner instead. A dropped third strike is still a strikeout in the box score, even with the batter safe at first. In each case the logic is the same: the hitter did nothing to earn the base.

The call between a hit and an error belongs to the official scorer, who is appointed by MLB and sits in the press box. Players care about those rulings more than they admit, because over a season a handful of them are worth several points. The symbols a scorer uses for each of these outcomes are decoded in our guide to keeping a scorecard.

The sacrifice fly has come and gone

A sacrifice bunt has been excused from the at-bat column since the 1890s. The sacrifice fly has a messier history: the exemption was in force in some periods and absent in others, and it was restored for good in 1954. Williams hit .406 in a season when a run-scoring fly ball cost him an at-bat. Researchers who have gone back through the play-by-play believe the modern rule would have added several points to his 1941 average.

Catcher's interference, the rarest row in the table, has its own page: the award and the manager's option to decline it are covered in our explainer on the catcher's interference rule.

What a good batting average is in MLB, and how the league figure has moved

There is no official scale, only the one that a century of box scores has drilled into people. For a regular across a full season it runs roughly like this.

Season average	How it is usually described	What it tends to mean
.330 and above	Elite	In the race for the batting title in most years
.300 to .329	Excellent	The traditional standard; a short list in any modern season
.270 to .299	Good	Clearly above the league
.240 to .269	Around average	Where the league as a whole has sat lately
.200 to .239	Below average	Needs power, walks or a premium glove beside it
Under .200	Below the Mendoza Line	Rare for anyone given a full season of at-bats

The middle of that scale is not fixed. It slides with the conditions of the era, and it has slid a long way.

American and National Leagues combined, shown in points, so 296 is a batting average of .296. Selected seasons chosen to show the extremes, not a continuous series.

Show the numbers

League-wide batting average in selected MLB seasons

Item	League average
1908	239
1930	296
1968	237
2000	270
2022	243

In 1930 the two leagues together hit .296. The National League by itself hit .303, which means the average hitter in that league that summer was a ".300 hitter," and Bill Terry of the New York Giants hit .401 to lead it. He was the last National Leaguer to reach .400.

Thirty-eight years later the combined figure was .237. That was 1968, the Year of the Pitcher, and Carl Yastrzemski won the American League batting title at .301 as the only qualifier in his league above .300. The same .301 that would have been a little above ordinary in 1930 was the best in the league.

So ".300" is not a constant. It has meant everything from league average to nearly unreachable. In recent seasons the number of qualified hitters finishing at .300 or better across both leagues has been about ten, sometimes fewer, where the hitting boom around 2000 produced several dozen a year.

Position bends the scale too. Teams have always accepted a lower average from a catcher or a shortstop than from a first baseman, because the first baseman's job description contains little else.

The Mendoza Line: .200 and the shortstop it is named for

Mario Mendoza could field. Born in Chihuahua, Mexico, he reached the majors with the Pittsburgh Pirates in 1974 and spent nine seasons there, in Seattle and in Texas as a shortstop whose glove kept him employed. His bat did not help. In 1979, playing 148 games for the Mariners, he hit .198.

The phrase started as clubhouse needling. The usual account credits his Seattle teammates Tom Paciorek and Bruce Bochte, who joked about hitters sinking below Mendoza in the Sunday newspaper listings of averages. They said it to George Brett of the Kansas City Royals when Brett was off to a slow start in 1980. Brett repeated it to reporters, Chris Berman began using it on ESPN's SportsCenter, and within a few years a private joke was part of the language.

There is an irony in the number. Mendoza's career average was .215, so the man himself finished on the right side of his own line. The joke was never about his career. It was about the weekly table, where he could usually be found near the bottom.

What the line stands for is a real threshold. Below .200, a hitter is making an out in more than four at-bats of every five, and almost nothing else he does can pay for it. The exceptions are instructive. Joey Gallo hit .199 for a full season in 2021 and remained an everyday player because he also hit 38 home runs and led the American League in walks. Remove either of those and he would have been on the bench by June.

Go back far enough and there is one extreme case. Bill Bergen, a catcher for Brooklyn in the first decade of the twentieth century, has the lowest career average of anyone with at least 2,500 at-bats, at .170. He lasted eleven seasons, on the strength of his throwing arm, in an era when a catcher's bat was treated as a bonus.

Mendoza went on to manage for many years in Mexico, where his long playing and managing career earned him a place in the Mexican Professional Baseball Hall of Fame. The phrase has since wandered well beyond baseball, into finance and politics, as a name for the lowest acceptable level of anything. Brett, for the record, recovered from his slow start. He hit .390.

How a batting title is won: 3.1 plate appearances per team game

Rule 9.22(a) gives the batting championship to the player with the highest average in his league, provided he has at least 3.1 plate appearances for every game his club was scheduled to play. In a 162-game season that is 502.

• 3.1Plate appearances per team game
• 502Minimum in a 162-game season
• 186Minimum in the 60-game 2020 season
• 498Tony Gwynn's plate appearances in 1996

From Rule 9.22(a) of the Official Baseball Rules. The minimum is tied to the schedule, so it fell to 186 in the 60-game season of 2020.

The threshold counts plate appearances, not at-bats, and the reason has a name attached. In 1954 the standard was a fixed number of at-bats. Williams hit .345 that year, the best figure in the American League, but pitchers walked him 136 times and he finished short of the at-bat minimum. Bobby Avila of Cleveland took the title at .341. A rule that punished a hitter for being too dangerous to pitch to was hard to defend, and by 1957 the requirement had been rewritten around plate appearances.

The phantom at-bats

A hitter who falls short is not automatically out of the race. The rule allows hitless at-bats to be added to his record until he reaches the minimum, and if his average is still the highest in the league after that penalty, he wins.

It happened in 1996. Tony Gwynn of the San Diego Padres hit .353 but missed several weeks hurt and came to the plate only 498 times. Four imaginary at-bats without a hit were added, which dropped him to .349. That was still ahead of Ellis Burks of Colorado at .344, so Gwynn took his seventh National League title. The record book lists him at .353, his actual average; the .349 exists only as a test he had to pass.

The same clause nearly produced an awkward champion in 2012. Melky Cabrera of the San Francisco Giants was suspended that August with 501 plate appearances, one short, and a .346 average that would have survived a single added at-bat. At his own request, MLB and the players' union agreed to set the provision aside for that season, and his teammate Buster Posey won at .336.

Titles are won league by league

Averages do not carry across a midseason trade between leagues. In 1990 Willie McGee was hitting .335 for the St. Louis Cardinals, with enough plate appearances to qualify, when he was traded to Oakland in late August. His National League figure froze. The rules counted only his National League at-bats, so McGee won the National League batting title as a member of an American League club. Eddie Murray of the Dodgers hit .330 and finished with the best average in the majors among qualifiers without winning anything, because McGee's combined mark across both leagues had slipped to .324.

Hitting .400: Williams's .406 and the seasons since

Before 1941 a .400 season was uncommon but not strange. It had been done a dozen times in the American and National Leagues since 1900. Rogers Hornsby did it three times in four years. Then Williams did it at 23, and the door shut.

His final day deserves the detail. The Red Sox finished at Philadelphia with two games that meant nothing in the standings. Manager Joe Cronin offered him the day off. Williams got four hits in five at-bats in the opener, added two in three trips in the second game, and raised his average by six points on a day when he could have protected it from a bench.

Since then the closest approaches in the two established leagues have been these.

Hitter	Season	Average	Hits and at-bats
Tony Gwynn, San Diego	1994	.394	165 in 419
George Brett, Kansas City	1980	.390	175 in 449
Ted Williams, Boston	1957	.388	163 in 420
Rod Carew, Minnesota	1977	.388	239 in 616
Larry Walker, Colorado	1999	.379	166 in 438

Gwynn's is the one that still stings. The players' strike ended the 1994 season on August 11, and he was hitting .394 with seven weeks unplayed. Three more hits in the at-bats he already had would have put him at .401. Brett was above .400 as late as the middle of September 1980. Williams's own .388 came in the season he turned 39, when he could no longer run out an infield hit; five more of those and he would have done it twice.

More recently Luis Arraez of the Miami Marlins carried a .400 average into late June of 2023. He finished at .354, which won the title easily and shows how much of a season is left after June.

The later .400 seasons the record book now carries

"Last .400 hitter" needs its qualifier. In 2020 MLB recognized seven Negro Leagues that operated between 1920 and 1948 as major leagues, and in 2024 their statistics were merged into the official record. Those seasons include Josh Gibson's .466 for the Homestead Grays in 1943, two years after Williams. Williams remains the last to do it in the American or National League. The background is in our history of Negro Leagues baseball.

Why it stopped is a better argument than whether it will happen again. The evolutionary biologist Stephen Jay Gould made the best-known case in his 1996 book Full House: as the general standard of play rose, the spread between the best and worst regulars narrowed, and the extreme values at both ends disappeared together. On that reading the vanished .400 hitter is evidence that the game improved.

What batting average leaves out: walks and extra bases

Roger Maris hit .269 in 1961. He also hit 61 home runs, broke Babe Ruth's single-season record and was voted the American League's Most Valuable Player. The batting champion that year, Norm Cash, hit .361. Anyone ranking the two seasons by batting average alone would have the wrong man.

The statistic has two blind spots, and they are built into the formula.

The first is the walk. Since a base on balls is not an at-bat, a hitter who walks 100 times and one who walks 20 times can carry identical averages while reaching base at very different rates. One of them is making far fewer outs. The measure that counts every way of getting aboard is covered in our guide to on-base percentage.

The second is the size of the hit. A bunt single that dies on the third-base line and a ball hit into the upper deck each add one to the numerator. Batting average cannot tell them apart. The measure that weights a double as two, a triple as three and a home run as four is slugging percentage.

This is why a hitter's record is now nearly always printed as three figures separated by slashes, something like .280/.350/.450: average first, on-base second, slugging third. Batting average survives as the opening number of the slash line because it still describes something real, which is how often a hitter turns an at-bat into a hit. It simply cannot be asked to describe his whole value. A .300 average made of singles from a man who never walks is worth less to an offense than a .260 average attached to 90 walks and 30 home runs, and front offices have priced players that way for a generation.

There is a subtler gap as well. Batting average treats every out as the same event, so a strikeout with the bases loaded and a ground ball that moves a runner to third cost the hitter exactly the same.

The 1941 season shows both blind spots at once. The .406 records nothing of the 147 walks Williams drew that year or the 37 home runs he hit, and those are a large part of why it was a greater season than the average alone can say.

How much of an average is luck: balls in play and small samples

A hitter controls some outcomes almost completely. He decides whether to swing, and his strikeouts and home runs are close to being his own doing. Everything else is a ball put in play between the lines, and what happens next depends partly on where nine fielders happen to be standing.

Across the majors, about three balls in play out of ten fall for hits, year after year. Individual hitters stray from that for real reasons: speed, line drives and hard contact all help. But over a few weeks an individual's rate can swing wildly for no reason at all. A line drive caught at the warning track and a broken-bat flare that drops in front of an outfielder are scored as an out and a hit, and nothing about the hitter's skill is revealed by either. Our explainer on BABIP goes through how analysts separate the two.

The plain arithmetic of chance shows how wide the noise is. Imagine a hitter whose true ability is exactly .270, and ask what he might reasonably hit over stretches of different lengths through luck alone.

At-bats	Roughly equivalent to	Range that covers about two-thirds of outcomes
50	Two weeks	.207 to .333
100	A month	.226 to .314
300	Half a season	.244 to .296
600	A full season	.252 to .288

Those ranges are one standard deviation either side of .270, worked from the ordinary formula for a proportion. A third of the time the same hitter will land outside them.

Read the second row again. A .270 hitter who bats .226 in May has not necessarily changed anything, and neither has the one who bats .314. A month tells you very little. Even a full season leaves a band nearly forty points wide, which is why a hitter can "decline" from .288 to .252 between one year and the next with the same swing.

This is also what makes a long hitting streak so improbable. The mathematics behind Joe DiMaggio's 56 games, and why nobody has got closer than Pete Rose's 44 in 1978, is laid out in our piece on the longest hitting streak in MLB history.

Front offices respond by trusting larger samples and by looking underneath the result at how hard the ball was hit. Fans can do a simpler version. Before reading anything into an average, check the at-bats beside it.

Why league batting averages fell: strikeouts, velocity and the shift

A strikeout is the one out that is guaranteed to be an out. There is no bad hop, no bloop, no hurried throw. So as strikeouts rise, batting averages fall, almost mechanically, and strikeouts have risen for most of forty years.

In 1980 roughly one plate appearance in eight ended in a strikeout. In the 2020s it has been more than one in five. In 2018, for the first time in major league history, the season ended with more strikeouts than hits.

Several things pushed in the same direction.

Velocity. The average four-seam fastball was under 92 miles an hour when league-wide pitch tracking began in 2008 and has since passed 94. A starter who once paced himself through eight innings now throws at full effort for five and hands over to a line of relievers who each throw harder still.

Pitch design. High-speed cameras and tracking data let pitchers build breaking balls to order, with movement chosen to miss a particular swing.

The hitters' own trade. Batters learned from the same data that a ball hit hard in the air is worth far more than a ground ball, and reshaped their swings to lift it. Those swings produce more home runs and more misses. Teams accepted the exchange knowingly, because the runs added by the power outweighed the points lost from the average. The measurements behind that decision are explained in our piece on exit velocity and launch angle.

Positioning. Clubs began stationing three infielders on one side of second base against pull hitters, with one of them often in shallow right field. Ground balls that had been singles for a hundred years became routine outs, and left-handed hitters lost the most.

What the 2023 limits were for

MLB responded to the last of these. Since the 2023 season a defense must have two infielders on each side of second base when the pitch is delivered, and all four must have their feet on the infield dirt. The league-wide average rose from .243 in 2022 to .248 in 2023, with left-handed hitters gaining the most on ground balls. The detail of what is and is not allowed is in our explainer on the shift ban.

Five points is a modest return, and the average slipped back again the following year. That is the honest reading of the experiment. Positioning was the cause that could be legislated, not the largest one. As long as pitchers keep adding velocity and hitters keep swinging for the seats, the league will go on hitting in the .240s, and no rule about where the second baseman stands will change it much.

The same statistic pointed elsewhere: pitchers, runners in scoring position and expected average

The formula does not care whose name is on it. Turn it around and it measures the men on the mound.

Opponents' batting average

Hits allowed divided by at-bats against gives a pitcher's opponents' batting average, printed as BAA, OBA or simply AVG on a pitching line. It answers a narrow question, which is how hard he is to hit, and ignores walks exactly as the hitter's version does. Pedro Martinez held opposing batters to a .167 average in 2000, the lowest figure for a qualifying starter in American or National League history. Whole lineups hit against him the way pitchers hit.

The weakness is the same one described in the previous section. A good share of opponents' average is decided by fielders and fortune, so it bounces from year to year more than a pitcher's strikeout or walk rate.

With runners in scoring position

"Scoring position" means second or third base, from where a single will usually bring a runner home. A hitter's average in those at-bats is shown on almost every broadcast, typically as proof that someone is or is not a clutch performer.

Treat it with suspicion. A regular gets perhaps 130 or 140 such at-bats in a season, which puts the figure in the one-month row of the table above, with all the noise that implies. Over a career, most hitters' averages with runners in scoring position settle close to their averages overall. A team's figure across a season is more meaningful than one player's, and even that tends not to repeat.

Other splits are sturdier. The gap between a hitter's averages against left-handed and right-handed pitching reflects a real, lasting advantage, and managers build whole lineups around it.

Expected batting average

Since 2015 every major league park has tracked how fast and at what angle each ball leaves the bat. Expected batting average, written xBA, uses those two measurements, plus the batter's running speed on certain kinds of contact, to estimate how often a ball hit that way has historically become a hit. A 110-mile-an-hour line drive caught by a diving center fielder counts as an out in batting average and as a near-certain hit in the expected version. Strikeouts count as zero in both.

The use of it is comparison. A hitter whose actual average sits 30 points under his expected figure has probably been unlucky and is a fair bet to improve. One who is 30 points over is living on borrowed hits.

The record book: Gibson's .372, Cobb's .367 and the single-season marks

For most of a century the answer to "highest career average" was Ty Cobb. Since the Negro Leagues statistics entered the official record in 2024, it is Josh Gibson.

Josh Gibson372

Ty Cobb367

Rogers Hornsby358

Joe Jackson356

Ted Williams344

Tony Gwynn338

Shown in points, so 372 is a career average of .372. A selection of the best-known figures, not the complete top of the list; Oscar Charleston, at a little above .360, also ranks above Hornsby. Totals for retired players are fixed.

Show the numbers

Selected career batting averages in the MLB record book

Item	Value
Josh Gibson	372
Ty Cobb	367
Rogers Hornsby	358
Joe Jackson	356
Ted Williams	344
Tony Gwynn	338

Gibson, a catcher for the Homestead Grays and the Pittsburgh Crawfords, hit .372 across the league seasons MLB counts. Those seasons were much shorter than the 154-game schedules of the white majors, so his record rests on far fewer at-bats than Cobb's, and MLB applies a lower qualifying minimum scaled to the Negro Leagues schedules. Oscar Charleston, another Negro Leagues star, ranks third at a little above .360.

Cobb's figure has its own footnote. MLB and the Elias Sports Bureau list him at .367. Several encyclopedias show .366, because researchers found in the 1980s that one of his games in 1910 had been entered twice, crediting him with two hits he did not get. The commissioner's office declined to alter the official total. Both numbers are in circulation and neither is a typo.

The best single seasons

Gibson's .466 in 1943 is the highest single-season average in the record book, and the Negro Leagues seasons added in 2024 brought other high marks with it. Before that merger the top figure was Hugh Duffy's .440 for the Boston Beaneaters in 1894, set the year after the pitching distance was moved back to 60 feet 6 inches and hitters briefly ran riot across the National League.

The records for the two leagues in the twentieth century belong to Nap Lajoie, who hit .426 in the American League's first major league season in 1901, and to Hornsby, whose .424 for the St. Louis Cardinals in 1924 is the National League's best since 1900. Both came in conditions that no longer exist, a point developed in our guide to the dead-ball era and what followed it.

Among hitters whose careers began after the Second World War, Gwynn's .338 is the highest career average, and he won eight National League titles to get there. Career marks for active players move with every game and are not listed here.

Where batting average came from: Chadwick and the 1887 experiment

Henry Chadwick learned to keep score at cricket matches. Born in England and raised in Brooklyn, he covered both games for New York newspapers in the 1850s and brought cricket's habit of record-keeping across with him. A cricketer's batting average is runs scored per dismissal. Baseball needed something else, because in baseball a run is a shared product: one man reaches base and another drives him in.

Chadwick's answer was to count the hit, the one thing a batter did entirely by himself. His early tables, in the 1860s, listed hits per game. That flattered men at the top of the order, who came to the plate more often, and by the early 1870s a per-at-bat version was in use. A correspondent of the New York Clipper named H. A. Dobson is usually credited with proposing it. When the National League was founded in 1876 it adopted hits divided by at-bats as its official measure of a hitter, and the batting champion has been crowned by it ever since.

The definition of a hit took longer to settle. In 1887 the rule makers, looking for more offense, declared that a base on balls would be scored as a hit. Averages ballooned. Tip O'Neill of the St. Louis Browns finished the American Association season at .492 by the scoring of the day. The experiment was dropped after one year, and when later record keepers recalculated 1887 with the walks removed, O'Neill's figure came down to .435, still one of the highest ever.

That single season says a good deal about the statistic. Its authors knew a walk was worth something. They tried counting it, disliked the result, and settled on leaving it out altogether, an omission that critics were attacking by the 1910s and that took most of the twentieth century to correct.

By then the number was too deeply planted to dislodge. It is the first leg of the Triple Crown, the first figure in the slash line, and the stat most Americans learn before any other. It opens every hitter's line on the batting pages of our baseball section, where the two measures built to repair it sit immediately to its right.