THE BOOK--Playing The Percentages In Baseball

Tuesday, September 04, 2007

Swing and miss

More great stuff from John Walsh. 

The pitch-by-pitch approach is one of those projects that I’ve had on the backburner for a long time.  It becomes an exercise in how a batter and pitcher should approach each count, based on the skill ranges of himself and his opponent, and game theory (or expectations that everyone has, and how to leverage that).  If you focus on what John quoted Ted as saying, “the single most important aspect of hitting was getting a good pitch to hit.” That’s the simple version.  But, if you try to expand on it, you might have threshhold levels of say +.01 runs at the 0-0 count, +.10 at the 2-0 count, and -.07 at the 0-2 count (all numbers for illustration only).  That is, your strike zone expands and contracts after every pitch.  And, like I said, you’d modify all that based on the particular parameters we have in hand.  It’s all a matter of when you should swing, and how quick you should swing.

On a related topic would be when to bring in your ace.  Perhaps in the 7th inning, you’d need an LI over 4 to make you think to bring him in.  Maybe in the 8th inning, that goes down to 3.  With 5 outs to go, you might want 2.7, with 4 outs, you might want 2.1.  In the 9th, maybe 1.8.  If he didn’t pitch in two days, maybe you drop all those numbers by 25%, etc.  (All numbers for illustration only.)

It’s all a question of optimization, with a whole set of dynamic variables, which themselves may be hard to quantify.