What is a perfect game in baseball? All we know about the rare achievement in the sport

The baseball season is in full swing, as the MLB season just crossed the one-third mark, while college baseball conference tournaments just wrapped up. The NCAA baseball tournament selection show, which announces which teams have qualified for the postseason and their seeding, is set for May 27.

Meanwhile, the NCAA Tournament begins with the NCAA Regionals on May 31. The NCAA Super Regionals are slated to kick off on June 7, while the College World Series starts on June 14. With additional attention set to come to the college baseball world, take a look at what a perfect game is below.

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What is a perfect game in baseball?

A perfect game is one of the rarest feats in baseball, at any level. It occurs when one or more pitcher throw a minimum of nine innings without allowing a baserunner from the opposing team.

If a batter reaches base in any way - whether it's via a hit, walk, hit by pitch, fielding error uncaught third strike, catcher's interference or fielder's obstruction - the perfect game is no longer in tact.

While baseball has been played for over 150 years at the Major League level, there have been just 24 perfect games - and just 22 in the modern era (1901 onwards). The most recent perfect game came last season when New York Yankees starter Domingo German accomplished the feat against the Oakland Athletics on June 28, 2023.

It was the first perfect game in nearly 11 years, with the feat being last accomplished by Felix Hernandez during the 2012 season. It was also the fourth perfect game in franchise history, going past the Chicago White Sox for the most by an MLB team. The Yankees won 11-0, marking the biggest margin of victory in a perfect game.

At the Division I level of college baseball, there have been 36 perfect games since the NCAA began tracking the feat in 1957, but just 20 of those were in full nine-inning games. The feat was most recently accomplished by Maryland Terrapins starting pitcher Ryan Ramsey against the Northwestern Wildcats in 2022.