Thinking About Horizontal Approach Angle
At the end of October, I wrote about the alterations José Urquidy made to his arsenal during the postseason, trying to estimate how much better or worse his pitches might have been given their velocity and movement changes. In that piece, I briefly touched on raw movement changes but mostly relied upon the vertical and horizontal approach angles (along with location and release point changes) of Urquidy’s pitches to try to fully encapsulate their movement. While the concept and value of vertical approach angle is rather intuitive, I figured it would be useful to go into horizontal approach angle here today and have fun with a little exercise.
This post is inspired in part by all that we have been able to grasp in the public sphere when it comes to vertical approach angle. Measuring the up-down angle of a pitch as it enters the zone is largely derived from the vertical movement measures we’re so accustomed to. Steep vertical movement on breaking pitches and “rising” four-seam fastballs in the upper parts of the zone have been coveted for a while now because we know those pitches are associated with whiffs and therefore success. Much less can be intuited by simply looking at the pitches with above average horizontal movement. Read the rest of this entry »