Chen’s changeup usage drop drastically in 2019, despite effectiveness from the pitch in a small sample size. It’s been a Jekyll-and-Hyde pitch throughout his career, so it’s possible he’ll abandon it to rely more on his other offspeed pitches.
Chen’s only meaningful offering last season was the curveball. The pitch resulted in a 30% K rate and a minuscule walk rate. A .268 career wOBA shows it can be effective consistently, but his other pitches just don’t amount to much.
Chen’s fastball was not good in 2019. Some of the issue was batted-ball luck, but all of a .405 wOBA can’t be explained away from that. A .278 ISO against the heater illustrates how the pitch was crushed.
Another dismal offering from Chen last season, his slider also touted an opposing wOBA north of .400, as well as an ISO of .287.
Chen relies on his four-seamer heavily, throwing it 53.1% of the time (similar to 54.4% in 2017). Unexciting but reasonably effective, it had a whiff rate of 18.1% and allowed a wOBA of .322 and batting average of .242.
Chen’s primary breaking ball, the slider, showed both below-average horizontal movement toward a righty at five inches (six inches was league average) and below-average drop at 31 inches (39 inches was league-average drop). Though he showed good command of the slider with a 43.4% zone rate, but it was a thoroughly uninspiring whiff pitch with a low 9.9% swinging-K rate (21.1% whiff rate).
Thrown almost exclusively to righties (239/256 pitches), the Chen changeup features below-average horizontal movement and drop. It had a fairly modest swinging-strike rate of 10.8% and was otherwise ineffective, allowing a wOBA of .362 and batting average of .323.
Featured primarily against right-handers (196/226 pitches), Chen’s curveball features below-average horizontal movement toward a righty at six inches (league average is nine inches) and above-average drop at 62 inches (average was 52 inches). The curve did a reasonable job limiting hitters to a .251 wOBA and .242 batting average. Overall, a slightly above-average 0.7 pVal.
The veteran lefty Chen barely threw his sinker in 2018, at just under 3% (10.8% in 2017). It was the antithesis of a Money Pitch, featuring a remarkably low 1.7% swinging-K rate.