What Counts as a No-Hitter or a Perfect Game

By 4Baseball Staff · November 5, 2026 · 11 min read

The official definitions of a no-hitter and a perfect game, what a scorer must decide, why a game under nine innings does not count, and how the 1991 committee ruling changed the record book.

A no-hitter sounds simple: a team goes a whole game without getting a hit. The official definition is stricter than that, and the difference decides whether some of baseball's most famous pitching performances are in the record book or not. A pitcher who retires 36 straight batters over 12 innings and loses in the 13th, for example, has no perfect game and, since 1991, no no-hitter either. A pitcher who throws eight hitless innings and loses does not have one. A pitcher who walks eight batters but allows no hit over nine innings, on the other hand, does.

This guide explains both definitions, walks through every way a runner can reach base and what each does to the pitcher's chances, and covers the rules that trip people up: games shortened by rain, extra innings, combined efforts by several pitchers, and the scorer's judgment on close plays. It also tells the story of the 1991 ruling by Major League Baseball's Committee for Statistical Accuracy, which set the definitions used today and removed more than two dozen games from the list.

The two definitions

A no-hitter is a game in which a team's pitchers, one or several, allow no hits over a game of at least nine innings. The team that goes hitless can still reach base by other means, and can still score. The pitchers need not have pitched the entire game alone; they only have to finish the game without a hit allowed, and the game must last nine innings or longer.

A perfect game is stricter. No batter on the other team reaches first base by any means in a game of nine or more innings. Twenty-seven up, twenty-seven down, in the common phrasing, when the game lasts the regulation nine innings. A perfect game is therefore always a no-hitter and always a shutout, and it has no walks, no hit batsmen, no errors that allow a runner and no other way on.

Everything else in this article follows from those two sentences. The definitions are the ones Major League Baseball uses for its records, and a scorer is expected to apply them. Because the rules refer to "nine innings or more", a shortened game cannot qualify, and because they refer to the whole game, a hit in the tenth inning ends a no-hitter that had survived nine.

Every way to reach first base

The easiest way to understand the difference is to list the ways a batter can reach, because only some of them count as hits.

The rows tell you why a no-hitter and a perfect game are different achievements. A pitcher can walk eight batters and hit another and still throw a no-hitter. A pitcher who walks one batter, and then retires the next 26 in a row, has thrown a no-hitter but not a perfect game. And a pitcher can lose a perfect game to an error by a fielder, which is a decision by the official scorer, not an act of the pitcher.

The dropped third strike deserves a word. If a catcher fails to hold a third strike and the batter reaches first base before the throw, the batter is credited with a strikeout and reaches base safely. The pitcher gets the strikeout, and the batter's reaching ends the perfect game even though no hit was allowed. It is one of the oddest ways to lose one.

Hit or error: the scorer's call

Whether a ball is a hit or an error is not decided by the pitcher, the batter or the manager. It is decided by the official scorer, an independent person at the game appointed to apply the scoring rules. The test the rules give is whether the fielder could have made the play with ordinary effort. If a ground ball takes a bad hop and no fielder could have fielded it with ordinary effort, it is a hit. If a fielder should have handled it routinely and did not, it is an error, and the batter has not earned a hit.

This sounds clear and is not. Close plays, particularly in the late innings of a game that has a pitcher three outs from history, are the most examined decisions in the sport. The scorer can change a decision after the game, and Major League Baseball has a process for appealing scoring decisions. That is why a no-hitter can be on the board at the end of a game and still be in question the next morning. It is also why careful accounts of a famous game often add a line about the key play: a hit on the scoreboard that was changed to an error, or the reverse.

A related point is that the scorer cannot give the pitcher credit for a no-hitter based on how well he threw. The pitcher can allow nine hard-hit balls that turn into outs and be credited with a no-hitter; he can allow one dribbler that is ruled a hit and not be. The rule measures the scorebook, not the pitching.

Why the game has to last nine innings

The phrase "at least nine innings" has two practical effects.

First, a game shortened by rain or by a curfew does not count, however well the pitcher threw. A baseball game becomes official once five innings have been completed, or four and a half if the home team is ahead, and a pitcher in a game that is called after six or seven innings can be credited with a win or a complete game. Under the definition now in use, he cannot be credited with a no-hitter, because the game did not reach nine. A fuller account of when games are official or suspended is in our guide to rain delays, suspended games and official games.

Second, a visiting-team pitcher has a particular problem. The visiting team bats in the top of each inning and pitches in the bottom. If the home team is ahead after the top of the ninth, the bottom of the ninth is not played, and the visiting pitcher has pitched only eight innings. The game is over, and no matter how many hitless innings the visitor has thrown, he cannot have thrown a no-hitter. A visiting pitcher can qualify only if the game goes to the bottom of the ninth or beyond, which happens only if his team is ahead or the game is tied after eight and a half innings.

A home-team pitcher has the opposite situation. If his team leads, he pitches the top of the ninth and the game ends when the visitors make the third out, so he has nine innings. If his team trails, he can still complete nine hitless innings, because runs can score on walks, errors and other plays that are not hits.

Extra innings

If a game goes beyond nine innings, the no-hit condition continues. A pitcher who has allowed no hits through nine innings and then allows one in the tenth does not have a no-hitter; the game is simply a game in which he pitched well for nine innings. To qualify, the pitchers must be hitless until the game ends. This is why a game that stays scoreless for ten or more innings is a rare thing: the pitchers must hold the other side hitless for the whole of it, and the team must find a run.

The consequence is that a pitcher can lose a no-hitter in a game that his team goes on to win. Pedro Martinez retired all 27 batters he faced for Montreal in 1995 against San Diego, and the game was scoreless. His club scored in the top of the tenth, and in the bottom of the tenth a reliever allowed a double. Martinez had nine perfect innings and no perfect game, and no no-hitter either. Harvey Haddix is the extreme example: in 1959 the Pirates left-hander retired the first 36 batters he faced for Pittsburgh at Milwaukee, 12 perfect innings, and then lost 1-0 in the 13th.

The 1991 ruling

Until 1991 the definition was looser. Games of fewer than nine innings were often counted as no-hitters. Games in which the pitcher held a team hitless for nine or more innings and then gave up a hit in extra innings were sometimes counted as well, and so were games in which a pitcher was hitless but lost. The record books were less consistent than they are now.

In September 1991, Major League Baseball's Committee for Statistical Accuracy ruled on the definition. Its decision, which the sport has followed since, was that a no-hitter must be a game of nine innings or more in which a pitcher or pitchers complete the game without allowing a hit. The committee's wording left no room for shortened games or for games in which the hitless streak ended after nine innings. The effect was to strike more than two dozen previously recognized no-hitters from the official list. The rationale was straightforward: a no-hitter should require a full game.

The decision also changed the status of a perfect game, which has the same nine-inning requirement and the additional condition that no batter reach. Perfect games were not many to begin with, and the effect was smaller. The most-discussed case was Ernie Shore's 1917 game for Boston. Shore came on after Babe Ruth, the starter, was ejected following a walk to the first batter, the base runner was thrown out trying to steal, and Shore retired the next 26 batters in order. For decades it was counted as a perfect game. The committee ruled it a combined no-hitter rather than a perfect game, since a batter had reached base before Shore came in.

Games that fell off the list

The 1991 ruling is easiest to understand through games that did not meet the new standard.

• Harvey Haddix, 1959. Twelve perfect innings, then a loss in the thirteenth. A hit in extra innings meant no no-hitter and no perfect game. The performance did not change; only its official category did.
• Andy Hawkins, 1990. The Yankees' Hawkins allowed no hits in a game at Chicago and lost 4-0. Because the Yankees were the visiting team and trailing, the bottom of the ninth was not played, and he had pitched only eight innings. By the new standard he did not have a no-hitter.
• Ernie Shore, 1917. The relief appearance described above, removed from the perfect-game list.

At the same time some games that look like failures survived. Ken Johnson of the Houston Colt .45s threw a nine-inning no-hitter in 1964 and lost 1-0 to Cincinnati on an error. It was a complete game of nine innings with no hit, and it stands on the list. The difference between Johnson and Hawkins is the home-team rule: Johnson, pitching for the home team, got to throw all nine innings.

Combined no-hitters

A no-hitter does not require one pitcher. If a starter and two relievers combine to hold the other side hitless over nine innings, the club has a combined no-hitter. The official wording of the rule allows it, and many teams have recorded one. The usage that matters for statistics is that credit goes to the team and to each pitcher who took part. A combined no-hitter does not give any pitcher a complete game or a shutout individually, so each pitcher's own line is whatever he actually pitched. How the pitchers in such a game come and go is covered in the lineup card and substitutions, and the rules for assigning wins, saves and holds are in pitching decisions explained.

A combined perfect game would also count under the same wording. So far, as far as the official list shows, every recognized perfect game has been thrown by a single pitcher.

Seven-inning games and other modern wrinkles

In 2020 and 2021 many doubleheader games were scheduled for seven innings. The nine-inning requirement still applied, so a pitcher who allowed no hits in a seven-inning game was not credited with an official no-hitter. Madison Bumgarner's seven hitless innings for Arizona in 2021 is the best-known example. The rule was not changed to accommodate the shorter format, which shows how firmly the standard is held.

Rain-shortened games remain the most common way a hitless game is left out. A game that is called in the sixth inning because of weather, with one team hitless, is an official game and a shutout or a win for someone, but it is not a no-hitter. The pitcher's line will show the full innings, the hits, and the zero, and the scorebook is correct as it stands.

The best-known examples

A short tour of the list shows how the definitions work in practice. Cy Young threw a perfect game for Boston in 1904. Don Larsen threw a perfect game for the Yankees in the 1956 World Series, the only perfect game in a postseason game. Sandy Koufax pitched one for the Dodgers in 1965. Randy Johnson threw one at age 40 in 2004. Felix Hernandez threw one for Seattle in 2012. In the postseason, Roy Halladay no-hit Cincinnati in a 2010 division series game for Philadelphia, which is the second no-hitter in postseason history after Larsen's perfect game. The two earliest perfect games are from 1880, when the rules of pitching and walks were very different from today's. Counting those, about two dozen perfect games have been thrown in the major leagues in all; check MLB's official list for the current number.

Common questions

Can a pitcher throw a no-hitter and lose? Yes. Ken Johnson did it in 1964 for the home team, pitching nine hitless innings and losing 1-0 on an error. A visiting pitcher who is trailing after eight and a half innings cannot, because the game ends with only eight innings pitched.

Is a rain-shortened gem a no-hitter? No. Since the 1991 ruling, the game must last at least nine innings.

Does an error ruin a no-hitter? No. An error does not count as a hit, so the pitcher keeps the no-hitter. It does end a perfect game, because a batter reached base.

Can a pitcher lose a perfect game on a strikeout? Yes, if the catcher fails to hold the third strike and the batter reaches first base.

Can several pitchers share a no-hitter? Yes. The team has a combined no-hitter, as long as the game lasts nine innings or more and no hit is allowed.

Where to go next

For the logic that makes strikeouts, walks and counts work the way they do, read counts, walks and strikeouts. The run totals in a game like Hawkins's depend on the difference between earned and unearned runs, which earned and unearned runs explained covers. To see how rare great pitching years are, read the lowest ERAs in baseball history. You can find recent final scores on the scores page and more rules explainers on the rules and umpiring topic page.