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.
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.
[2] Baseball Prospectus renamed it True Average (TAv) in 2010, in an attempt to make it more accessible.
Therefore, a hitter in the PCL may have notably depressed raw statistics (a lower batting average, fewer home runs, etc.)
REqA in turn is adjusted to account for league difficulty and scale to create EqA.