If we are more concerned with the impact of player's performances (in terms of winning and losing), I would just stick with WPA. Again, WPA just looks at how much the probability of a team winning changes per AB, summing up the net change for each batter. It can be somewhat unfair, since not every player is given an equal opportunity to impact a game (Branyan, for instance) but I guess we don't care about such things. Here are how some of the batter's did in terms of WPA/600 AB: Rivera: 6.68 Braun: 3.61 Fielder: 3.27 Branyan: 3.27 Kapler: 3.17 Weeks: 2.20 Hardy: 2.00 Cameron: 1.12 Dillon: .24 Hall: -.53 Hart: -1.04 Counsell: -1.79 Kendall: -1.79 Interesting stuff. Rivera, Branyan and Kapler all made the best of their limited opportunities. Weeks did well with translating his mediocre offensive numbers into a positive impact. Hart being right next to Counsell and Kendall, while playing a corner outfield spot, shows how silly his B- really is.