Equivalent average

Equivalent Average (EqA) is a baseball metric invented by Clay Davenport and intended to express the production of hitters in a context independent of park and league effects. It represents a hitter's productivity using the same scale as batting average. Thus, a hitter with an EqA over .300 is a very good hitter, while a hitter with an EqA of .220 or below is poor. An EqA of .260 is defined as league average.

The date EqA was invented cannot readily be documented, but references to it were being offered on the rec.sport.baseball usenet group as early as January 14, 1996. Baseball Prospectus renamed it True Average (TAv) in 2010, in an attempt to make it more accessible.

Definition and rationale

In the formula given in the box above, the abbreviations are: H=Hit, TB=Total bases, BB=Bases on balls (walks), HBP=Hit by pitch, SB=Stolen base, SH=Sacrifice hit (typically, sacrifice bunt), SF=Sacrifice fly, AB=At bat, CS=Caught stealing.

EqA is one of several sabermetric approaches which validated the notion that minor league hitting statistics can be useful measurements of Major League ability. It does this by adjusting a player's raw statistics for park and league effects.