An immaculate inning occurs in baseball when a pitcher strikes out all three batters he faces in one inning using the minimum possible number of pitches: nine. This has happened 115 times in Major League history and has been accomplished by 105 pitchers (80 right-handed and 25 left-handed). Major League Baseball's first immaculate inning was accomplished by John Clarkson of the Boston Beaneaters against the Philadelphia Quakers on June 4, 1889; and the most recent by Ryan Pepiot of the Tampa Bay Rays on September 18, 2024. Use of the term "immaculate inning" first appeared in newspaper reporting after 2000. Six pitchers have accomplished the feat more than once, including Hall of Famers Lefty Grove, Sandy Koufax, and Nolan Ryan, and active pitchers Chris Sale, Max Scherzer, and Kevin Gausman. Koufax, Sale, and Scherzer are the only pitchers to achieve an immaculate inning three times. Koufax accomplished his first immaculate inning while throwing his first no-hitter, becoming the only player to do both in a single game. Sloppy Thurston, Ryan, Wade Miley, Thomas Pannone, Reid Detmers, and Hayden Wesneski are the only rookies to have achieved the feat. Ryan and Gausman have struck out three batters on nine pitches in both the American League and National League. Danny Jackson is the sole pitcher to have thrown an immaculate inning in the postseason, doing so in the seventh inning of Game 5 of the 1985 World Series. Jackson pitched a complete game, winning 6–1 and staving off elimination for the Kansas City Royals, who eventually won the series in seven games. While an immaculate inning typically occurs with the bases empty, a nine-pitch, three-strikeout performance can also be accomplished by a relief pitcher who enters the game with one or more runners on base. On May 8, 2014, Brad Boxberger of the Tampa Bay Rays entered a game against the Baltimore Orioles with the bases loaded and proceeded to strike out the side with nine pitches. No player has ever struck out four batters on 12 pitches in an inning, with one of those batters reaching base on an uncaught third strike. No pitcher has thrown more than one immaculate inning in a game. Jesús Sánchez of the Florida Marlins came within one pitch of that feat on September 13, 1998. Facing the Atlanta Braves, Sánchez struck out the side in the bottom of the second inning on 10 pitches and threw an immaculate inning in the bottom of the third inning: six consecutive strikeouts on 19 pitches. Just one game has seen two pitchers throw immaculate innings: on June 15, 2022, Phil Maton and Luis Garcia of the Houston Astros struck out the same three Texas Rangers batters in the second and seventh innings respectively.

Frequency by decade

The frequency of immaculate innings has varied widely throughout baseball history. There were only 30 immaculate innings in the 114 Major League seasons from 1876 to 1988, but the next 30 occurred in the 21 seasons from 1989 to 2009. The pace has since picked up even more, with 55 immaculate innings in the 15 seasons from 2010 to 2024.

Players