Adjusted batting average

The adjusted batting average is a baseball statistic that compensates for factors inherently unique to each individual hitter such as era, home ballpark, pitching trends, rule changes, and handedness; it also counts only the first 8,000 at-bats to account for late career decline. It was first formulated in 1999 by statistician Michael J. Schell in the book Baseball's All-time Best Hitters: How Statistics Can Level the Playing Field published by Princeton University Press. Using his calculations from said formula, Schell posited that Tony Gwynn is the greatest MLB hitter of all-time with the highest adjusted batting average of .342. Joseph Gallian, a mathematician who independently analyzed Schell's formula in a book published by the Mathematical Association of America wrote, "Of course, Schell's adjusted batting average is far superior to the traditional batting average."