Jackson has a show-me curveball, throwing it 8% of the time in 2019 and sitting at 83.5 mph. The hook got 24% more break than the major-league average, but still got hammered, allowing a .706 SLG and .410 wOBA against it.
Sitting 96.1 mph, Jackson used his four-seam fastball 37.9% of the time in 2019, finishing with a .341 batting average against it. Getting slightly above-average movement on both planes, the pitch had a 26.3% K rate and had a 10.4% SwStr%.
The slider is Jackson’s main offering, and was used 54% of the time in 2019, getting 34% less break than the major-league average. That didn’t stop the power of its whiff potential, finishing with a 39.4% K rate and 21% SwStr%, along with a minuscule 3.7% walk rate.
Jackson’s slider is a tight, hard thrown pitch coming in at nearly 87 mph on average. He does get a lot of chase outside of the zone on the pitch and it led to a very solid 17.4% swinging-strike rate and a 34.9% strikeout rate. Combine that with a 66% ground-ball rate and there is a lot to like about the pitch as long as the infield defense can remain solid behind him.
It’s interesting to note how Jackson’s pitch mix has evolved. Since entering the league, his four-seam usage has been on the decline, dropping 26% since 2015. While batters had a .237 average against the pitch, and it didn’t have fantastic results, the 104 wRC+ is the best he’s ever held on the pitch.
Jackson’s curveball is his third offering that gets hit around quite a bit. While he can get an occasional strike early in the count with the pitch, it’s not a great swing and miss offering. Batters hit .391 off the pitch with a .174 ISO, and he’s much better off funneling more use into the slider.
Jackson only threw a few cutters, and it’s basically a faster version of his slider with less drop. It showed up mostly in 2-2 counts, making it entirely possible that it is a result of overthrowing the slider, especially since it’s not been a part of his repertoire in previous seasons.