Ellsbury's Steal of Home
Last night, Jacoby Ellsbury pulled off the rare play of a straight steal of home. The feat electrified the Fenway crowd, but was it a good play? It was the bottom of the 5th with the Red Sox leading 2-1. The Yankees' southpaw Andy Pettitte had just intentionally walked Kevin Youkillis to get to JD Drew to load the bases with two outs. Pettite threw a fastball for a swinging strike one, then a breaking ball outside for a ball. Then Ellsbury took off....
Let's look at the factors which affect the chances that a player is able to steal home or not and whether Ellsbury had them in his favor.
1) Speed of the runner. Obviously, this is vital and Ellsbury has great speed.
Overall, Ellsbury had 5 of 6 factors in his favor, meaning he had a decent chance to pull off what's become an increasingly rare feat. However, did the game situation call for a steal of home? Let's look at the factors relating to this.
1) Score/Inning. The best time to run is late in the game when the game is tied or you are down by one. The Red Sox were up by one in the 5th, which wasn't ideal.
Ellsbury only had 1 out of 5 of these factors really in his favor, meaning while he might be capable of stealing home, it would be a risky play. From a WPA perspective (not taking into account batter or count), the Red Sox had a 72.1% chance of winning before the steal. Afterwards it increased to 79.8%. Had he been thown out, the chances would have dropped to 65.8%. The break-even point for the steal was 45%, meaning that if Ellsbury were safe 45% of the time, it would be a good play.
Stealing home is so difficult, that ideally all 11 factors that I outlined would have to be in a runner's favor before attempting a straight steal of home. Ellsbury had only about half working for him in this case, meaning that while exciting, it might not have been the smartest baseball play ever. But Ellsbury beat the throw (and beat it fairly easily), so it's hard to argue with results - perhaps he knew something we didn't. In any case, cheers to him making the most exciting play in baseball thus far in 2009.