Plate Appearance Depth for pitchers
After taking a look at how hitters did as plate appearances grew longer, it seemed easy enough to see how the pitchers fared.
I decided to take a look at two Tigers with contrasting styles, Jeremy Bonderman and Kenny Rogers
The MLB 2006 norm was for OBPs to start increasing once the plate appearance went beyond 4 pitches. However, Bonderman’s stayed relatively flat throughout. This could be indicative of Bonderman’s unwillingness to “give in” to an opposing hitter. It was an approach that had pretty good results for Bonderman, but the rise in slugging percentage may indicate he got burned this way on occasion.
Now with Kenny Rogers there seems to be an opposite effect. The OBP rises while the slugging percentage tapers off.
If I had to speculate on the big reason for the difference it is style brought about by “Stuff.” Rogers relies on location and the corners to compensate for an 86mph fastball. If he has to put the ball over the plate he’s at a disadvantage. His game is to get hitters to chase borderline pitches and hit them weakly. If a hitter lays off, or fouls off, those offerings early in the count, they are probably disciplined enough to lay off them later in the count as well.
On the other hand, Bonderman’s fastball let’s him stay int he zone and his slider probably induces quite a few swings on pitches out of the zone.
One thing the two had in common was an ability to end at-bats after 3 pitches. For both pitchers half of the PAs ended by the 3 pitch mark and the MLB average wa 47%.
Now whether or not any of my speculation has any merit remains to be seen. I looked at two pitchers in one season who’s numbers happened to play out like I would have expected. Way too little data here to say how much tendencies/style/stuff impacts these numbers. Regardless, I still thought it was interesting enough to play around with.
As I did with the hitters, I’m making the Excel files available(padepth_pit.zip) . Please let me know if you find anything of interest.