I’m embarking on a fairly sizable project to see if pitch F/X can influence the world of player projections (in fact if my adviser will allow it I’m going to try and use it as my masters thesis). The first step I’m taking is coming up with predictive models for batted ball type based on “stuff” (horizontal and vertical movement and velocity) and location. My initial fooray into that has been GB%. Here’s what I’ve got so far…. I’ll give you direct R output and then give a quick explanation. NOTE this is for fastballs (all kinds) only, other pitch types still to come.