The ninth inning An official game (regulation game in the Major League Baseball rulebook) is a game in which nine innings are played, unless the game is scheduled with fewer innings, extra innings are required to determine a winner, or the game must be stopped before nine innings are played, e.g. due to a rain delay of more than one hour. A complete game is six innings or less. In 1877, when the National League was established as a major league, its rules specified that games could not end until the ninth inning had elapsed, nor could they end without any ball being put in play during the last half-hour of the eighth inning. These rules were changed in 1895 so that by today's standards, games could end at any time during an actual play. In either case, if the game ended before the ninth inning, then that is when it would become a legal game. From 1877 to 1995, there were only five no-hitters thrown in baseball's history. From 1996 to 2015, there have been 29 no-hitters pitched in MLB history. In 2016, the number of no-hitters pitched has risen again to 30, making it the most recent season there have been more no-hitters than there have been earned runs allowed. A perfect game is considered the highest form of achievement for a pitcher, requiring all batters up to and including the ninth batter to retire every single time he takes the plate.