Stewart’s changeup is his least-used pitch, and it’s easy to see why: Batters racked up a 100% zone contact rate against the offspeed offering, decimating the pitch for a .533/.556/.867 triple slash. The changeup has never returned a positive pVAL for Stewart, and it’s a pitch that should stay buried in his repertoire.
Stewart’s fastball boasts a spin rate well above league average (83rd percentile on Baseball Savant), and he’s shown consistency at keeping the heater in the strike zone (59.5% zone rate), but that’s about where the good things to say run out. The four-seamer was responsible for a prodigous .371 ISO from opposing batters, along with a 1.045 OPS and .424 wOBA.
While Stewart turned to his changeup as his go-to secondary pitch during his 2018 campaign, his slider leapfrogged the change piece in his arsenal’s pecking order last season. Despite putting up a scalding 42.9% strikeout rate a season before, the K% on his slider plummeted to just 10.5% in 2019, and natters torched the breaking ball to the tune of a 40% HR/FB rate.
Stewart’s two-seamer had poor movement, though he controlled the pitch well. It was his least-bad offering, as opponents batted .250 against the pitch, albeit with a .455 slugging percentage.
Stewart had roughly average movement on his change. Considering that he threw it over the plate only 25.3% of the time. the 35.5% chase rate isn’t super impressive. Hitters managed a 172 wRC+ against the pitch.
Considering Stewart only threw his slider 23 times in 2018, there isn’t much to go off of. It was primarily used as a putaway pitch based on its 42.9% strikeout rate, though when hitters made contact, they slugged .857.