What Is a Clean Inning in Baseball?

Discover the Definition and Significance of a Clean Inning in America's Favorite Pastime
Written by Mark Bailey
Last updated on

A clean inning means a pitcher had a dominant performance that inning. Another term for a clean inning is an immaculate inning. However, there are some differences between these terms. In this post, we’ll dive deeper into this concept by exploring its origins as well as its implications for a successful outing on the diamond.

  • A clean inning is when a pitcher doesn’t give up any hits, walks, or runs in an inning.
  • A clean inning is significant because it can change the course of the game, and momentum is key in baseball.
  • To record a clean inning, simply note that the pitcher went through 1-3 batters with no one getting on base (a “1-2-3” inning).

In a clean inning, the pitcher doesn’t give up a run or a hit. In an immaculate inning, the pitcher records three outs in nine pitches. These nine pitches are all strikes as well. As you can tell, an immaculate inning is much rarer in comparison to a clean inning.

What is a clean inning in baseball?

A clean inning happens when a pitcher gets through an inning with ease. He must not allow a single hit, walk, or run to be recorded. While he doesn’t need three strikeouts, he can’t let anyone get on base.

A clean inning is a dominant inning that plays a massive role in a team’s success. While a clean inning is great, an immaculate inning is even more spectacular. This is done by a pitcher getting three outs in nine pitches. Some pitchers achieve this by recording three strikeouts with nine straight strikes. Others might get three flyouts.

However, they must all result in nine pitches for it to be considered an immaculate inning. A clean inning is just one that results in no harm for the opposing team.

Does a clean inning matter in baseball?

Yes, a clean inning is huge for the team that throws it. By doing so, they create a boost of momentum heading into the next inning. For the team that just suffered a clean inning, they must find a way to get things rolling again.

A clean inning can change the entire course of a game. In sports and baseball especially, nearly everything is reliant on momentum. In basketball, you have long scoring runs. In baseball, you have clean innings and/or immaculate innings. These innings play a significant role in how the game plays out. If your team has more than one clean inning in a game, you are in a great position to win.

Examples of clean innings

One of the more common examples of a clean inning is done by three straight strikeouts. A clean inning can occur under a multitude of circumstances. There can be many different results, but they all must lead to three outs with no hits or walks.

It does not matter how the pitcher gets these outs. They could all be strikeouts or all be ground-outs. Either way, the pitcher has achieved a clean inning by doing so. An example of an immaculate inning would be a pitcher still throwing three strikeouts.

However, the difference is the number of pitches it takes to do this. An immaculate inning must be done in 9 pitches exactly. To achieve this, a pitcher can strike out all three hitters in three pitches each. While it sounds easy, you must be exceedingly efficient in doing something like this. Immaculate innings don’t happen too often in today’s game. You may see a couple every season.

How are clean innings recorded?

While there isn’t a specific abbreviation for a clean inning, it will still be recognized in the stat book. If a pitcher pitches one clean inning, his stats will read 1 IP, 0 H, 0 R. This represents one inning pitched with zero hits and zero runs given up.

At the end of this stat line, the number of strikeouts from the inning will also be recorded. The same goes for an immaculate inning. There is no abbreviation for this on the stat sheet. However, anyone with baseball knowledge can recognize a clean inning or an immaculate inning based on the stat line.

Another way of saying “clean inning” is to say “1, 2, 3 inning.” This is because the pitcher went through the first three batters and got them all out. He did not have to face more than three batters in that inning. This is the more commonly used term between the two.

Frequently Asked Questions

Who pitched the first clean inning in MLB history?

While there is no recording of the first clean inning, there is for the first-ever immaculate inning. In 1889, John Clarkson struck out three batters on nine pitches. He was the first recorded pitcher ever to do so.

What are the most clean innings in an MLB game?

Since there is no way to record a clean inning, there is not much information on the most clean innings in a single game. Pitchers like Roger Clemens, who have thrown multiple no-hitters, have thrown more than four clean innings in one game. You usually need to have a good number of clean innings to throw a no-hitter in that game.


A clean inning is an impressive feat that each pitcher in the MLB strives for. Another way of saying ‘clean inning’ is to say “1, 2, 3 inning.” You will probably hear announcers on TV call it this instead of a clean inning. If no hits, runs or walks happen, a pitcher can throw a clean inning.

A more impressive clean inning is called an immaculate inning. To throw an immaculate inning, a pitcher must finish an inning in exactly nine pitches. He must also give up no hits, walks, or runs. He can achieve these three outs in nine pitches in any shape or form. He just cannot let anyone get on base.