THE BOOK--Playing The Percentages In Baseball

Monday, June 08, 2009

The 2-run sac fly

Pujols hit a 2-run sac fly in the first inning.  Gonzalez made a leaping catch in the alley, who then tossed it to the CF to relay it home, but not in time.  Fantastic fielding play.  For Pujols, this added +.035 wins or +0.27 runs, even though he “made” an out. 

It of course could have been alot worse.  The RE that Pujols found himself in was a 2.05 expected runs for the inning.  Had he hit a 2-run double, the Cards would have 2 runs in the bank, plus another 1.19 runs expected, for a gain of 1.14 runs.  Is there a way you could have done this in your head?

First off, realize that before Pujols, there was a runner on 2B.  After Pujols, had he hit a double, you would still have a runner on 2B.  So, that’s a 1-run gain right away.

As for the runner on 3B, he had around an 86% chance of scoring with 0 outs.  So, scoring him only adds .14 runs.  So, 1 plus .14 is 1.14.

Gonzalez’s diving play turned a 1.14 run play in to a .27 run play, meaning he saved .87 runs in the process.  That is, he knocked out Pujols from his 2B perch with 0 outs (worth 1.19 runs) to bases empty 1 out (almost like a CS), or worth .30 runs.  And 1.19 minus .30 is .89 runs.

(The .87 and .89 don’t match because I’m using two different RE matrix sources, this one, and the ones I gave Fangraphs.)