In baseball, a no-hitter (also known as a no-hit game and colloquially as a no-no) is a game in which a team was not able to record a single hit. Major League Baseball (MLB) officially defines a no-hitter as a completed game in which a team that batted in at least nine innings recorded no hits. A pitcher who prevents the opposing team from achieving a hit is said to have "thrown a no-hitter". This is a rare accomplishment for a pitcher or pitching staff—only 305 have been thrown in MLB history since 1876, an average of about two per year. In most cases, no-hitters are recorded by a single pitcher who throws a complete game; one thrown by two or more pitchers is a combined no-hitter. The most recent major league no-hitter by a single pitcher was thrown on September 13, 2020, by Alec Mills of the Chicago Cubs against the Milwaukee Brewers at Miller Park. The most recent combined no-hitter was thrown on August 3, 2019, by Aaron Sanchez, Will Harris, Joe Biagini, and Chris Devenski of the Astros against the Seattle Mariners at Minute Maid Park.
It is possible to reach base without a hit, most commonly by a walk, error, or being hit by a pitch. Other possibilities include the batter reaching first after an uncaught third strike, catcher's interference or fielder's choice. A no-hitter in which no batters reach base at all is a perfect game, a much rarer feat. Because batters can reach base by means other than a hit, a pitcher can throw a no-hitter (though not a perfect game) and still give up runs, and even lose the game, although this is extremely uncommon, and most no-hitters are also shutouts. One or more runs were given up in 25 recorded no-hitters in MLB history, most recently by Ervin Santana of the Los Angeles Angels of Anaheim in a 3–1 win against the Cleveland Indians on July 27, 2011. On two occasions, a team has thrown a nine-inning no-hitter and still lost the game. It is theoretically possible for opposing pitchers to throw no-hitters in the same game, although this has never happened in the majors. Two pitchers, Fred Toney and Hippo Vaughn, completed nine innings of a game on May 2, 1917, without either giving up a hit or a run; Vaughn gave up two hits and a run in the 10th inning, losing the game to Toney, who completed the extra-inning no-hitter.