Nathan Eovaldi Is Making Delicious Lemonade

If motor preferences were the final word on pitcher performance, Nathan Eovaldi would be sitting on a beach somewhere.
Eovaldi throws from a low slot, releasing his pitches from an average arm angle of 30 degrees. (Zero degrees is fully sidearm; 90 degrees is straight over the top.) Many low-slot pitchers have a supination bias. There are downsides to being a supinator — their preference for cutting the baseball tends to produce crummy four-seam fastballs — but they usually have no trouble throwing hard breaking balls; they can also more easily harness seam-shifted wake to throw sinkers, sweepers, or kick-changes. Low-slot supinators, like Seth Lugo, can basically throw every pitch in the book. High-slot pronators like Ryan Pepiot or Lucas Giolito don’t have that sort of range, but make up for it with excellent changeups and high-carry fastballs.
Eovaldi is, tragically, a low-slot pronator. Not many low-slot pronators make it to the big leagues. The pronation bias blunts their ability to throw hard glove-side breakers, and the low arm angle obviates the pronator’s nominal advantage, killing the carry on their fastball. As Tyler Zombro of Tread Athletics (now a special assistant of pitching for the Cubs) said in his primer video on motor preferences, “I know in stuff models and just off of Trackman alone, this arsenal with this slot is not that attractive.” Read the rest of this entry »