Petti: Expanding the edges of the strike zone

From SABR member Bill Petti at The Hardball Times on May 5, 2014:

It has been quite a while since Jeff Zimmerman or I wrote anything about our Edge% metric. For those that haven’t seen it, we attempted to quantify pitcher control by bucketing pitches into various zones based on Mike Fast’s work on the called strike zone during the PITCHf/x era. Specifcally, we were interested in how well a pitcher works the black–the horizontal edges of the strike zone–relative to the heart of the plate.

After a few iterations, the result was Edge%, a metric that encompasses the horizontal edges of the called strike zone based on batter handedness and height. For size, we determined that the inside edge was roughly .6 of a foot in width and the outside edge was .3 of a foot, with specific location dependent on batter handedness. For a sense of proportion, the width of a baseball is roughly .3 of a foot.

In the past year or so since we published our research we have heard numerous questions about the vertical edge of the strike zone. How would we define those edges? What difference–if any–does throwing to those locations make? Fair questions, and today is our first attempt at tackling the issue of the vertical edges of the zone. I say first attempt as I won’t claim that these new metrics should represent the finished product. In fact, trying to determine the optimal vertical edges of the strike zone has proven much harder than our initial work on the horizontal edges.

Read the full article here:

Originally published: May 5, 2014. Last Updated: May 5, 2014.