Wednesday, August 04, 2010
How many runs does a great fielding pitcher save?
If there’s one potential place for ball-hogging, it’s with pitchers. Colin shows us his list for pitchers, with Greg Maddux making 388 more plays than the average pitcher (adjusting for presumed GB BIP). Normally, you would just apply a standard 0.70ish runs per play (the difference between a sure out and a sure mostly-infield single). But, if Maddux doesn’t make the play, there’s a decent chance the C or 3B makes the play on the bunt, or the 2B/SS make the play on balls near the middle. So, it looks like this:
30% of the time: sure hit becomes sure out
20% of the time: probable hit becomes sure out
10% of the time: possible hit becomes sure out
40% of the time: sure out from non-pitcher becomes sure out for the pitcher
Numbers for illustration purposes only. So, if we treat the run value of the infield single as -.43 runs and the out as +.27 runs, we get something like this:
0.30 x .70 x 100%
+ .20 x .70 x 70%
+ .10 x .70 x 30%
+ .40 x .70 x 0%
= .33 runs
I am NOT suggesting that we should use 0.33 runs instead of 0.70 runs. I am suggesting we try to figure it out. Until then, I like to simply split it down the middle, and instead of using 0.70 runs, divide by two and use 0.35 runs.


I haven’t read the article, but I’m assuming this data includes pop ups? More so than bunts, I would think pop ups could distort the data as some pitchers never field them while others (presumably Maddux would be one of them) always field them. Since 99% of pop ups collected by pitchers would become outs anyway, it would be nice to remove them from the study.