List of Major League Baseball perfect games

Over the 140 years of Major League Baseball history, and over 210,000 games played, there have been 23 official perfect games by the current definition. No pitcher has ever thrown more than one. The perfect game thrown by Don Larsen in game 5 of the 1956 World Series is the only postseason perfect game in major league history and one of only two postseason no-hitters. The first two major league perfect games, and the only two of the premodern era, were thrown in 1880, five days apart. The most recent perfect game was thrown on August 15, 2012 by Félix Hernández of the Seattle Mariners. There were three perfect games in 2012, with no other year ever having more than two thrown. By contrast, there have been spans of 23 and 33 consecutive seasons in which not a single perfect game was thrown.

The first two pitchers to accomplish the feat did so in 1880, under rules that differed in many important respects from those of today's game: for example, only underhand pitching—from a flat, marked-out box 45 feet from home plate—was allowed, it took eight balls to draw a walk, and a batter was not awarded first base if hit by a pitch.Lee Richmond, a left-handed pitcher for the Worcester Ruby Legs, threw the first perfect game. He played professional baseball for six years and pitched full-time for only three, finishing with a losing record. The second perfect game was thrown by John Montgomery Ward for the Providence Grays. Ward, an excellent pitcher who became an excellent position player, went on to be inducted into the Baseball Hall of Fame.

Though convention has it that the modern era of Major League Baseball begins in 1900, the essential rules of the modern game were in place by the 1893 season. That year the pitching distance was moved back to 60 feet, 6 inches, where it remains, and the pitcher's box was replaced by a rubber slab against which the pitcher was required to place his rear foot. Two other crucial rules changes had been made in recent years: In 1887, the rule awarding a hit batsman first base was instituted in the National League (this had been the rule in the American Association since 1884: first by the umpire's judgment of the impact; as of the following year, virtually automatically). In 1889, the number of balls required for a walk was reduced to four. Thus, from 1893 on, pitchers sought perfection in a game whose most important rules are the same as today, with two significant exceptions: counting a foul ball as a first or second strike, enforced by the National League as of 1901 and by the American League two years later, and the use of the designated hitter in American League games since the 1973 season.

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