Defending the Jeter Bunt

Over the last 10 years or so, one of the truisms that has been associated with statistical analysis is that bunting is bad. And it’s mostly true – a lot of sacrifice bunting is unproductive and wasteful, and teams would be be better off letting their hitters swing away rather than giving up outs to try to increase their odds of scoring one run. However, as MGL noted in War And Peace his post the other day, laying one down is a correct play more often than a lot of us will admit.

So, with that said, let’s talk about Derek Jeter‘s decision to try to move the runners over in the 8th inning last night. The Yankees had just taken a two run lead on Jorge Posada’s single to center, which put runners at first and second with nobody out. At that point, the average win expectancy for a major league club is 92.0 percent. For the Yankees, with Mariano Rivera ready to pitch the 8th and 9th inning, it was almost certainly higher than that.

Rivera, as everyone knows, is not an average closer. He’s probably the best relief pitcher of all time, and he’s in the conversation for greatest postseason pitcher in the history of the game as well. In 85 playoff games, he’s thrown 130 innings and has an ERA of 0.76. He’s given up more than one run in exactly two of those appearances, and in one of them, the Yankees had a four run lead and won anyway.

Every other appearance he’s ever made in the postseason, it’s been zero or one run allowed. So, with a two run lead and Rivera ready, the Yankees were already sitting pretty. Getting one more run would have pushed the average win expectancy to 96 percent, and again, the Yankees real odds would have been even higher than that, thanks to their robo-closer.

Jeter successfully laying down a bunt in the 8th inning would have increased the Yankees odds of scoring one more run from 61.8 percent to 68.9 percent. Moving the runners over would have added seven percent to the odds of Melky Cabrera scoring – that’s a real benefit. The cost of the sacrifice bunt is in the reduced chance of a multi-run inning, but in that situation, there really wasn’t a tangible difference between a three run lead and a 10 run lead. Those additional runs that could have scored in a big rally would have been essentially worthless.

The first two Jeter bunt attempts will be criticized by members of the statistical community as part of the reflexive don’t-bunt-ever strategy that has gained too much popularity, but they were the right play. The two-strike bunt attempt really was a bad idea (the additional cost of a foul turning into an out reduces the odds enough to make swinging away more likely to produce a single run, which was the original goal), but the first two stabs at it, Jeter was making the right play.

Playing for one run can be the right move, especially when you have Mariano Rivera ready to come into the game.

By the way, since I’ve been so hard on Girardi in the playoffs, let me just say that using Rivera for the six out save was absolutely the right call, and an important one to get right. Kudos to him for not letting an inferior reliever start the inning.