THE BOOK--Playing The Percentages In Baseball

Monday, March 23, 2009

Modelling approaches and strike zone

Dave Allen is shaping up to be my new PITCHf/x for 2009, following on the heels of Josh Kalk, Mike Fast, and John Walsh.  Indeed his model is identical(*) to mine (if done by count):

The run value of a pitch is determined by the outcome of four events.

1. If the batter swings at the pitch or not.
2. If no to 1, whether the taken pitch is called a ball or a strike.
3. If yes to 1, whether the batter makes contact.
4. If yes to 3, the run value of that contact.

This is why it’s important that MLBAM continue to make this data accessible to the public.  You can have the top 30 analysts all working for MLB, and then you can have the next 3000 best analysts working for free, and the latter group will produce more insight.  The open source movement is exactly what PITCHf/x needs.

(*) I include a couple more subgroups (like handedness as Dave is doing), but the above basically represents 90% of my core model.