What Is an Immaculate Inning in Baseball?
Quick answer
A half-inning in which a pitcher strikes out all three batters on nine pitches, every one of them a strike.
In this article
An immaculate inning is a half-inning in which a pitcher strikes out all three batters on nine pitches, the minimum possible. Every pitch is a strike: called, swinging or a foul ball with fewer than two strikes. It's one of the rarest feats in baseball.
The rules of an immaculate inning
- Three batters, three strikeouts. No walks, no hits, no balls in play.
- Nine pitches. Three per batter, so not a single ball.
- Fouls count only before two strikes. A foul with two strikes adds a pitch, and the inning can't be immaculate.
Striking out three batters in an inning on more pitches is called striking out the side. See what "the side" means.
How rare is it?
MLB has seen only about 125 immaculate innings in its history. The first was thrown by John Clarkson of the Boston Beaneaters in 1889. Three pitchers have done it three times:
| Pitcher | Immaculate innings |
|---|---|
| Sandy Koufax | 3 (1962, 1963, 1964) |
| Max Scherzer | 3 (2017, 2018, 2021) |
| Chris Sale | 3 (two in 2019, one in 2021) |
| Nolan Ryan | 2 (1968, 1972) |
In 2022 the Houston Astros threw two in the same game, against the same three Texas Rangers hitters.
What it takes
- Elite command. The pitcher has to throw strikes on every pitch.
- Aggressive hitters, or overpowering stuff. Hitters who take a strike and swing through the next two help.
- Luck. One foul ball with two strikes and it's over.
Related feats
- Triple Crown: pitchers can win one too, leading in wins, strikeouts and ERA
- Full count: the count an immaculate inning never reaches
- Dropped third strike: a strikeout where the batter can still reach base
More definitions: baseball terms explained.
Frequently asked questions
What is an immaculate inning?
An immaculate inning is a half-inning in which a pitcher strikes out all three batters on the minimum nine pitches, so every pitch is a strike.
Do foul balls count in an immaculate inning?
A foul ball with fewer than two strikes counts as a strike, so it can be one of the nine pitches. A foul ball with two strikes would add a pitch and ruin the immaculate inning.
How many immaculate innings have there been in MLB history?
About 125, starting with John Clarkson in 1889. Sandy Koufax, Max Scherzer and Chris Sale have each thrown three.
Is an immaculate inning the same as striking out the side?
No. Striking out the side just means three strikeouts in a half-inning, on any number of pitches. An immaculate inning requires exactly nine pitches.
