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Mood Music - Cell Therapy by Goodie Mob

At Baseball Nation, Jeff Sullivan wrote a cool article on which teams have been getting favorable and unfavorable strike calls. By comparing to a Pitch F/X strike zone, you can determine if a team is getting more or less strikes called for them than one would expect. These results can then be used to make inferences about pitch framing and receiving.

(Mike Fast's article from Baseball Prospectus that started this whole thing)

In Sullivan's article, the Yankees have had the third best rate of "stealing" strikes, behind only the Brewers and Braves. Using the Pitch F/X data on Fangraphs, I took things back a few more seasons to see if there was a way to isolate the impact of different catchers.

From this data, we can calculate the number of strikes that we would expect, given the Pitch F/X strike zone.

In 2012, Yankees pitchers have thrown 6483 pitches and they have been inside the Pitch F/X zone 47.9% of the time. So, by multiplying the two, we get 3105 pitches in the strike zone, leaving 3378 pitches outside the strike zone. Of those 3378 pitches, 28.7% of them were swung at, giving an additional 970 strikes. By adding the two, we can conclude that the Yankees pitchers would have thrown 4075 strikes if the zone was called precisely by the Pitch F/X data.*

*If you're checking my math, all of this is subject to small rounding errors.

As the Yankees pitchers have actually thrown 4106 strikes, they have come out thirty-one strikes ahead. There are a number of things that could contribute to that. Bad officiating, pitchers with consistently good control, Russell Martin's receiving, and inaccuracies in the Pitch F/X data all seem reasonable. Going back a few more years (click the table to embiggen or if cut off):

There is not only a correlation, but a strong correlation to Jorge Posada being behind the plate and truly dreadful results. I hate to draw black and white conclusions, but it looks for all the world like he really was a disaster at receiving those last few years. Sorry, Jorge :(

Thankfully, things seem to be much better with Russell Martin behind the plate, which is good. With the way that the front office seems to think so highly of his catching ability, it is encouraging to actually see some numbers that support that.