April 21, 2021

The Importance of Fastball Shape (FanGraphs)


Velocity is all the rage these days, and why shouldn’t it be? It’s fun to see that third digit light up on a radar gun or show up on the scoreboard. And it’s happening more often than ever. From Opening Day through the weekend, eight pitchers combined for a total of 28 pitches over 100 mph, with Emmanuel Clase hitting the mark nine times out of the 11 cutting fastballs he threw on Sunday. It’s certainly exciting, but velocity isn’t everything. Yes, I want to know how hard someone is throwing when evaluating a pitcher, but my first question after that is what is the shape of the pitch?

A decade ago, scouts based their fastball grades almost entirely on velocity. Above-average velocity? Above-average fastball. But with the emergence of technologies like TrackMan, Hawkeye and Rapsodo, that one-to-one relationship has become a relic. There are pitchers who throw in the upper 90s who have average fastballs because of their shape and other intangibles; there are some with average velocity that are nonetheless plus pitches for the same reason. Because of this, the scouting scale has changed and is beginning to capture variables outside of just miles per hour. Some teams…

Read “The Importance of Fastball Shape” at FanGraphs