What is an At-Bat in Baseball?

When reading about how well a baseball player performed in a game, one of the statistics people look at is how many hits they had versus how many times they came up to bat. Oftentimes, there are discrepancies when comparing one player’s batting performance to another player’s batting performance. One player may have gone 1-3 while another player went 0-1, even though they came up to the plate the same number of times. This leads a lot of people to wonder what is an at-bat and how do you calculate at-bats?

In baseball, an At-Bat (AB) is any Plate Appearance (PA) that results in a hit, error, fielder’s choice or a non-sacrifice out. Any other result, like a walk, hit-by-pitch, sacrifice fly, sacrifice bunt, or catcher’s interference, does not count towards an official At-Bat.

When thinking about what is an At-Bat, it is beneficial to first learn about what is a Plate Appearance because an At-Bat is like a sub-category of a Plate Appearance.

What is Considered an At-Bat?

At-Bat vs Plate Appearance

While an At-Bat and a Plate Appearance are statistics that share similar qualities, there is an important difference between the two.

A Plate Appearance (PA) is counted when a player completes their batting turn, regardless of the result. An At-Bat (AB) is any Plate Appearance that results in a hit, error, fielder’s choice, or a non-sacrifice out. Any other result of a Plate Appearance does not count as an At-Bat.

Another way to think about it is that an At-Bat is a subtype of Plate Appearance. While any batting result will lead to a Plate Appearance being counted, only a subset of those results will count towards a player’s At-Bat statistic.

What Qualifies as an Official At-Bat?

After understanding that an At-Bat is a subset statistic of a Plate Appearance, the next logical question to ask is “what constitutes an At-Bat in baseball?”

An official At-Bat (AB) occurs when a Plate Appearance (PA) ends in one of four ways:

• Batter gets a base hit
• Batter reaches base on an error
• Batter reaches base on a fielder’s choice
• Batter strikes out or gets out on a play that is not ruled a sacrifice fly or a sacrifice bunt

Any other result is not counted towards a player’s official At-Bat, but let’s dive into specifically what those non-At-Bat scenarios could be.

What is Not an Official At-Bat?

Just as important as understanding the scenarios that make up an official At-Bat, it’s just as important to understand what scenarios don’t count as an official At-Bat in baseball.

According to the MLB rulebook, there are five scenarios where a Plate Appearance (PA) does not count as an official At-Bat (AB):

• Batter hits a sacrifice fly or a sacrifice bunt
• Batter walks on four balls
• Batter gets hit by a pitch
• Batter is awarded first base due to interference or obstruction
• A pinch hitter enters the game with two strikes and completes the strikeout

The scenario where a pinch hitter enters the game with two strikes is a rare occurrence and will usually happen if a batter gets hurt during their turn at-bat.

In a scenario where a pinch hitter enters the game with two strikes and completes the strikeout, the batter who was removed from the game would be charged an At-Bat and a strikeout. However, if the pinch hitter completed the plate appearance in any other way, the pinch hitter would be credited with the result of that plate appearance.

Why is a Walk Not an At-Bat?

When thinking about what is considered an At-Bat and what isn’t considered an At-Bat, many people wonder why a walk is not an At-Bat. I also found myself wondering the same thing so I researched the history of walks and At-Bats.

In short, a walk is not an At-Bat (AB) because At-Bats are used to calculate a player’s batting average. Including walks as an At-Bat would considerably change a player’s batting average, so walks are removed as an official At-Bat.

What’s interesting is the history of how an At-Bat was scored.

In 1876, walks were considered an error on the pitcher, and the batter was charged an At-Bat. This rule ended up hurting the batting average for batters who walked, but walks were pretty rare at this point in baseball’s history because pitchers were expected to deliver a pitch a batter could hit.

From the years 1877 to 1886, walks were not considered to be an official At-Bat. Walks were still considered an error on the pitcher, but they were not included in a player’s batting average because they were not an official At-Bat.

Then for one year in 1887, walks counted as a hit and as an At-Bat. The idea was to reward the batter and punish the pitcher for a walk, but this rule was heavily criticized because of how it impacted a player’s batting average.

This rule also confused the public. When reading about how well a player performed, the public would typically look at how many hits a player got, but because walks counted as a hit they had to dive deeper into the stats to see how many of those hits were base on balls and how many were actual hits.

In 1888, the rules reverted back to walks being an error on the pitcher and not included in a player’s official At-Bat. This helped alleviate the batting average issues from the year before, but there was still some confusion around when a walk is an earned run and when it was an unearned run.

In 1889, the rules committee voted to no longer call a walk an error on the pitcher. This rule change helped differentiate between an earned run and an unearned run when a walk occurs. This rule change also paved the way to how we calculate walks today, which is that a walk does not count as an At-Bat and is not considered an error on the pitcher.

A Strikeout is Considered an At-Bat

Just like when a batter walks, a batter does not put the ball in play when they strike out. Walks don’t get counted as an at-bat, but what about strikeouts? Do strikeouts count as at-bats?

In baseball, strikeouts are considered at At-Bat (AB). Any non-sacrifice out in baseball counts as an official At-Bat and strikeouts fall into that category because they didn’t intentionally get out to move over a base runner.

So even though a walk and a strikeout seem like they share some similarities when it comes to counting an At-Bat, they are scored quite differently.

Reached On Error Counts as an At-Bat

Whenever players put the ball in play, the defense does their best to make an out. On occasion, the defense will make an error and the batter will get on base. Does reached on error (ROE) count as an At-Bat?

In baseball, reached on error (ROE) counts as an At-Bat. Even though the batter safely made it to first base, they only did so because of an error by the defense instead of by getting a base hit.

If the defense were to make the play, the batter would have been out and it would have counted as an unsuccessful At-Bat. So when an error is made, an At-Bat is still charged to the batter because they should have been out.

An At-Bat is Used To Calculate Batting Average and Slugging Percentage

Once the general concept of an At-Bat is understood, the next logical question is “how do you use At-Bat?”

An At-Bat (AB) is used to calculate a player’s batting average (AVG) and a player’s slugging percentage (SLG). Some advanced stats use At-Bats, but a player’s batting average and a player’s slugging percentage are the most well-known ways to use a player’s At-Bat statistic.

So an At-Bat is a critical piece of the puzzle for determining how well a player is hitting for average (batting average) and how well a player hits for extra-base hits (slugging percentage).