In Major League Baseball, 38 pitchers have thrown a nine-pitch, three-strikeout half-inning, literally throwing nothing but strikes, a total of 41 times. This feat is also known as an immaculate inning.
The feat has been accomplished in every regulation inning: four times in the 1st, four times in the 2nd, six times in the 3rd, five times in the 4th, once in the 5th (Cone), once in the 6th (Johnson), four times in the 7th, seven times in the 8th, eight times in the 9th, and once in the 12th (Thurston).
Three pitchers have accomplished the feat twice: Grove, Koufax, and Ryan. Of them, Grove is the only pitcher ever to have achieved the feat twice in the same season, and Ryan is the only pitcher ever to have achieved the feat in both the National and American Leagues, as well as being the only right-handed pitcher to accomplish the feat twice. All three are members of the Hall of Fame.
Three of the pitchers who have accomplished the feat have done so in their rookie seasons: Eller, Thurston, and Ashby.
Four of the pitchers who have accomplished the feat are members of the 3000 strikeout club: Johnson, Ryan, Gibson, and Martinez.
Koufax's first nine-pitch/three strikeout inning came in the first inning of his first no-hitter.
Four of the pitchers who have accomplished the feat have also thrown perfect games (though not in the same game): Koufax, Bunning, Cone and Johnson.
Guidry's and Wilson's immaculate innings are the only two to come in the ninth inning of a complete game. Both were shutout victories.
Nine of the pitchers who have accomplished the feat have been elected to the Major League Baseball Hall of Fame: Clarkson, Waddell, Vance, Grove, Bunning, Koufax, Ryan, Gibson, and Sutter.
Thurston is the only pitcher in Major League history to accomplish the feat in extra innings.
Grove and Ryan are the only pitchers with 300 career wins to have accomplished the feat.
The 24-year-and-345-day gap between Grove's half-inning and Hoeft's half-inning in the longest span without a pitcher achieving the feat; the one-day gap between Koufax's half-inning and Bruce's half-inning is the shortest span.
1928 was the first year in which the feat was accomplished twice (both times by Grove); 1964 was the first year in which two pitchers accomplished the feat (Koufax and Bruce); 1991 was the first year in which three pitchers accomplished the feat (Ashby, Cone, and Harnisch); 2002 was the first year in which four pitchers accomplished the feat (Isringhausen, Kim, Martínez and Lawrence)
Three franchises have seen their pitchers accomplish the feat four times, more than any of the others: The Houston NL franchise, with Bruce, Harnisch, Magnante, and Backe, the Dodgers--in Brooklyn and LA--with Ragan, Vance, and Koufax twice, and the Athletics, with Waddell, Grove twice, and Harden. The Braves and Cubs have each seen the feat performed three times.
As of the 2008 season, the feat has been accomplished twenty-six times in the National League, twelve times in the American league, and three times in interleague play.