A few days ago, we had a guest post about advanced statistics taking away the human side of baseball. Today, we had a guest post about an advanced statistic used to evaluate a postseason decision that was largely based on the human side of baseball (the relationship between a pitcher and his catcher). I’m sure numbers were in play when Joe Girardi chose to start Jose Molina with A.J. Burnett, but that was ultimately a gut decision by the manager.
What I loved about David’s post this morning was that he didn’t try to answer whether Girardi made the right decision, he only looked at just how much of an offensive risk Girardi was taking.
In a follow-up post on his own blog, David added two bits of criticism about his own work: 1. He didn’t allow for the playoffs, in which expected run totals are lower, and thus Posada’s offense might have been more important. 2. The difference in expected wins for Posada and Molina were not based on games in which they specifically caused the win.
To me, that’s a key point, and it’s actually part of what I liked about David’s post. The reality is that a single, pre-selected player is unlikely to make the difference between a win and a loss. David’s numbers suggest that roughly 70 percent of games would end the exact same way, whether Posada or Molina was in the lineup. Occasionally Molina’s offense would actually be an improvement (you have to allow for the fact that Molina could go 4-for-4 on a night Posada would strikeout four times).
Fact is, the Yankees won three out of five Burnett starts in the postseason. He pitched especially well in the three wins, pitched terribly in one of the losses and had a bit of a Jekyll-and-Hyde game in Los Angeles. If Molina had any impact in that brilliant Game 2 of the World Series, then I’d say the decision was well worth it (although, as a general rule, I agree with the go-with-your-best-players theory).
If you’re interested in more of David’s work, here’s a study he did on payroll efficiency.