Stewart’s changeup has been an afterthought pitch throughout his career. It’s been only an average pitch in a limited sample size.
A forgettable offering for Stewart, his big hook hasn’t done much to trick batters, He’s held batters to just a .261 BAA over his career with the pitch, but doesn’t throw it often enough for that number to be meaningful yet.
Stewart all but dropped the 4-seamer from his repertoire after disasterous results in 2018. he threw it alongside his sinker and was swatted to the tune of a .456 wOBA. It’s likely to disappear in 2020.
After benefitting from an unsustainable BABIP in 2018, Stewart’s sinker fell back down to earth in 2019. While still able to generate groundballs, hard contact led to a wOBA of .452 last season, and that won’t do.
If Stewart is able to find a roster spot, it will be because of his slider. His only reliable plus pitch has been thrown effectively with a 22% K-rate and a minuscule .190 wOBA over his career,
Stewart threw his sinker 48.7% of the time which was more than twice as often as the four-seamer. It had a very low 11.6% whiff rate. It was good at keeping balls on the ground with an average launch angle of just 1 but was otherwise fairly nondescript.
Stewart’s four-seamer averaged 93.2 mph and maxed out at 95.5 mph. It got hit really hard across a small 137-pitch sample last year to the tune of a .441 wOBA and .407 batting average allowed.
The curve was Stewart’s third-most-used pitch at 11.1%. It had a 28.6% whiff rate across a small 70-pitch sample. The pitch showed above-average horizontal movement away from a right-hander at 16 inches (average horizontal movement is 10 inches). And below-average vertical drop of 48 inches (54 inches was the average).
Stewart’s fourth pitch at 9.1%. Of the 57 thrown, 46 were to lefties. The pitch showed just about average vertical and horizontal movement. It also had a very modest 7% swinging-strike rate.
Rookie Kohl Stewart only threw 36.2 IP in 2018. The slider was his fourth pitch at 9.2%. He showed good command of the pitch with a 35.1% zone rate. But it was not a very good pitch at enticing swings misses out of the zone with a modest 26% chase rate. The pitched showed below average vertical drop of 30 inches (average was 37 inches).