As the science of pitch design matures, we’re getting better at understanding the how and why of the best pitches in baseball. Gerrit Cole’s fastball is great because it has great ride and velocity, Zack Greinke’s changeup is good because of the plus movement in two dimensions, and Rich Hill’s curveball is amazing because it mirrors the spin on his fastball and then drops off the table.



That isn’t to say that there aren’t pitches that are demonstrably good that confound researchers. Patrick Corbin’s elite slider is one of them.



“There are few pitchers that make me want to throw my laptop across the room because they inflate the errors on my arsenal score model, and he is absolutely one of them,” said Driveline Baseball analyst Dan Aucoin with a laugh, expressing frustration at trying to fit Corbin’s slider dominance into his existing research on the value of pitch shape and velocity.



The ground level...