Batting average against

In baseball statistics, batting average against (denoted by BAA or AVG), also known as opponents' batting average (denoted by OBA),^{[lower-alpha 1]} is a statistic that measures a pitcher's ability to prevent hits during official at bats. It can alternatively be described as the league's hitters' combined batting average against the pitcher.

Sandy Koufax had a .179 batting average against in 1965, the best in Major League Baseball for that season.^[1]

Definition

Batting average against is calculated as:^[2]

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

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:

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

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):^{[3][lower-alpha 2]}

${\displaystyle BAA={\frac {H}{AB}}}$

For example, in 2021, Max Scherzer had the best (lowest) batting average against in Major League Baseball among qualified pitchers.^{[3][lower-alpha 3]} Scherzer's BAA for the 2021 season was:^[3]

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

See also

• Hits per nine innings (H/9)
• Walks plus hits per inning pitched (WHIP)

Notes

1. Not to be confused with on-base average (OBA), more commonly known as on-base percentage (OBP).
2. See section "Player Batting Against", hover over "BA" column header.
3. See section "Player Batting Against", sort by column "BA".

References

1. "1965 Major League Batting Against". Baseball-Reference.com. Retrieved June 4, 2022.
2. "Classic Fantasy Baseball Glossary - Definitions of Terms". ESPN.com. 2001. Archived from the original on 26 August 2007. Retrieved 2007-07-14.
3. "2021 Major League Baseball Batting Against". Baseball-Reference.com. Retrieved June 4, 2022.

External links

• OBA Calculator at captaincalculator.com