Calculator
Definition – What is Equivalent Average / True Average?
Equivalent average shows a player’s hitting ability independent of park and league effects.
It is similar to Batting Average (BA). A higher number means that the player hits more balls for each at bat.
EqA is often used to compare hitting ability across leagues, for example between minor and major leagues.
In 2010 it was renamed to True Average (TAv).
Formula – How to calculate EqA
Equivalent Average = (Hits + Total Bases + (1.5 x (Walks + Hit by Pitch)) + Stolen Bases + Sacrifice Hits + Sacrifice Flies) ÷ (At Bats + Walks + Hit by Pitch + Sacrifice Hits + Sacrifice Flies + Caught Stealing + (Stolen Bases ÷ 3))
Equivalent average is listed to 3 decimal points.
Example
A batter has the following statistics: Hits: 164 | Total Bases: 255 | Walks: 22 | Hit by Pitch: 4 | Stolen Bases: 18 | Sacrifice Hits: 6 | Sacrifice Flies: 18 | At Bats: 520 | Caught Stealing: 7 | Stolen Bases: 18
EqA = (164 + 255 + (1.5 x (22 + 4)) + 18 + 6 + 18) ÷ (520 + 22 + 4 + 6 + 18 + 7 + (18 / 3))
EqA = (164 + 255 + (1.5 x 26) + 18 + 6 + 18) ÷ (520 + 22 + 4 + 6 + 18 + 7 + 6)
EqA = (164 + 255 + 39 + 18 + 6 + 18) ÷ (520 + 22 + 4 + 6 + 18 + 7 + 6)
EqA = 500 ÷ 583
EqA = 0.858
Therefore, the pitcher’s Equivalent Average (EqA) is 0.858
Sources and more resources
- Wikipedia – Equivalent Average – Wikipedia’s entry on EqA.
- Glossary entries on EqA from Baseball Prospectus (EqA), Baseball Prospectus (TAv),
- Rules on baseball and baseball statistics from Major League Baseball, NCAA (Baseball), NCAA (Softball), NCAA (Baseball and Softball), NFHS, and the International Baseball Federation.
- More on EqA / True Average from Clay Davenport – About EqA, Baseball Prospectus – Call it True Average, The Book – Why is EqA so complicated?, Grantland – The best hitter you’ve never heard of, Beyond the Box Score – How, in the name of Barry Bonds, does EqA work?, and Hardball Times – The Monster in the Mirror.