Cole: Pitch types and the strike zone

From Bryan Cole at Beyond the Box Score on December 4, 2014:

A couple of weeks ago, I used contour plots to see if umpires called different types of pitches differently. This qualitative approach didn’t produce any clear distinctions, but noted strike zone guru Jon Roegele wasn’t convinced by my conclusions. In the comments of that article, he wrote,

The thing that I’m not convinced about is whether you’d be able to see the difference in strike zone size from the 50% contour images. If there is a difference it’s likely less than 25 sq. inches, and if this was spread around the periphery of the contour then I think it would look “the same” but in reality would be showing a different sized zone.

So let’s start by finding the area under each curve, starting for left-handed batters on 0-0 counts. This table shows the area under select contours; for instance, the area under the 50 percent contour counts the number of square-inch bins with at least a 50-50 mix of called strikes and balls.

Read the full article here:

Originally published: December 4, 2014. Last Updated: December 4, 2014.