Batting average against

Definition

Batting average against is calculated as:

BAA = \frac{H}{BF-BB-HBP-SH-SF-CINT}

for which:

• H is the number of hits allowed by the pitcher
• BF is the number of batters faced
• BB is the number of base on balls
• HBP is the number of hit batsmen
• SH is the number of sacrifice hits
• SF is the number of sacrifice flies
• CINT is the number of catcher's interference

For example, if a pitcher faced 125 batters and allowed 25 hits, issued 8 walks, hit 1 batsman, allowed 2 sacrifice hits, allowed 3 sacrifice flies, and had 1 instance of catcher's interference, the pitcher's BAA would be calculated as:

BAA = \frac{25}{125-8-1-2-3-1} = \frac{25}{110} = .227

Reference site Baseball-Reference.com more simply defines BAA as hits divided by at bats, as "at bats" for a pitcher equates to the above noted denominator (batters faced less walks, hit by pitch, sacrifice hits, sacrifice flies, and catcher's interference):

BAA = \frac{H}{AB}

For example, in 2021, Max Scherzer had the best (lowest) batting average against in Major League Baseball among qualified pitchers. Scherzer's BAA for the 2021 season was:

BAA = \frac{H}{AB} = \frac{119}{644} = .185

Notes

References

References

1. "1965 Major League Batting Against".
2. (2001). "Classic Fantasy Baseball Glossary - Definitions of Terms". [[ESPN.com]].
3. "2021 Major League Baseball Batting Against".