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.[1] 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.[2] Baseball Prospectus renamed it True Average (TAv) in 2010, in an attempt to make it more accessible.[3]
- ^ Davenport, Clay (2004-02-24). "About EqA". Baseball Prospectus. Baseball Prospectus Basics. Archived from the original on 2015-06-29. Retrieved 2015-09-07.
- ^ "The rec.sport.baseball FAQ". Newsgroup: rec.sport.baseball. 1996-01-14. Archived from the original on 2010-08-10. Retrieved 2015-09-07.
- ^ Jaffe, Jay (2010-02-25). "Call it True Average". Baseball Prospectus. Prospectus Hit and Run. Archived from the original on 2015-05-19. Retrieved 2015-09-07.
This spring, we at BP have chosen to rebrand EqA as True Average (abbreviated TAv). Why? Because we feel strongly that the new name underscores our ability to get a 'True-r' grasp on the quality of a hitter than the aforementioned traditional or more modern stats do. Quite frankly, we're hopeful that this simple, easy-to-remember name can reach a wider audience.