Milwaukee Brewers reliever Eric Gagne has had a tough 2008 full of performance problems, mental instability and injury issues alike. Gagne is on the disabled list right now and Walkoff Walk favorite Salomon Torres has taken his place as Brewers closer.
How's Salomon doing? Since Gagne went on the DL on May 21st, Torres has appeared in eleven games and saved all nine of his opportunities. He's allowed eight hits and three walks in thirteen innings and gave up one run in a non-save sitch against the Astros. Not bad!
That's all well and good, but let's head over to Baseball Prospectus and noodle around with their nerdy stat reports. They have a stat called "Win Expectation over Replacement, Lineup-adjusted", or WXRL, that is explained well by Derek Jacques in this primer:
Win Expectation breaks down each game situation--inning, score, number of outs, number of runners on base, and which bases they're on--that occurs in the major leagues, all to measure how the transition from one situation to another alters a team's chance of winning the game.
So basically, a relief pitcher is rated on how difficult the situation is when he enters the game and how much he contributes to his team's chances to win the game. Come into the ninth inning with two outs, the bases empty and a three-run lead and pick up a save? That's good. Come into the ninth inning with a one-run lead, no outs and the bases loaded and pick up a save? That's great. WXRL measures that.
Our friend Salomon Torres is sixth in the NL with a 2.479 WXRL, so he's worth about 2.5 wins over a replacement level pitcher. Not bad! For comparison purposes, Brad Lidge is first in the NL with a 3.577 WXRL and Eric Gagne is dead last on the Brewers with a -0.575 WXRL. Gagne is half a win worse than a replacement pitcher, so Ned Yost would be better off picking a fan from the crowd than putting Gagne in the bullpen when he returns from injury. Hey, at least Yost is making the right move with the closer role.