Gross production average

Gross production average (GPA) is a baseball statistic created in 2003 by Aaron Gleeman, as a refinement of on-base plus slugging (OPS). GPA attempts to solve two frequently cited problems with OPS. First, OPS gives equal weight to its two components, on-base percentage (OBP) and slugging percentage (SLG). In fact, OBP contributes significantly more to scoring runs than SLG does. Sabermetricians have calculated that OBP is about 80% more valuable than SLG. A second problem with OPS is that it generates numbers on a scale unfamiliar to most baseball fans. For all the problems with a traditional stat like batting average (AVG), baseball fans immediately know that a player batting .365 is significantly better than average, while a player batting .167 is significantly below average. But many fans do not immediately know how good a player with a 1.013 OPS is.

The basic formula for GPA is: $$\frac{{(1.8)OBP} + SLG}{4}$$

Unlike OPS, this formula both gives proper relative weight to its two component statistics and generates a number that falls on a scale similar to the familiar batting average scale.

All-time leaders
The all-time top 10 highest career gross production averages, among players with 3,000 or more plate appearances:
 * 1) Babe Ruth .3858
 * 2) Ted Williams .3754
 * 3) Lou Gehrig .3592
 * 4) Barry Bonds .3516
 * 5) Jimmie Foxx .3449
 * 6) Rogers Hornsby .3396
 * 7) Hank Greenberg .3367
 * 8) Manny Ramirez .3312
 * 9) Mickey Mantle .3287
 * 10) Stan Musial .3274