Dylan Cease's slider was the single-most valuable pitch in baseball last year. It's the reason why he finished runner-up in the American League Cy Young, and it's the reason he paid tribute to it in clunky verse.
But while his breaking ball stole the show, a lot of its success was built on the stabilization of his fastball.
Cease's early-career struggles were so confounding because he generated shockingly few strikeouts for a guy who threw as hard as he did, and with as much spin on his breaking stuff. Poor control was part of the problem, but he also served as a poster boy for spin efficiency -- a missing poster, that is. He wanted his fastball to ride, but it cut instead, resulting in startlingly low whiff rates, especially relative to the velocity.
It took a couple seasons, but Cease eventually ironed out his fastball. Maybe it didn't explode like Michael Kopech's best four-seamer, but it stopped meeting hitters halfway, and that set up his slider to finish the job.
Alas, Cease is experiencing a little bit of a relapse. He hasn't slipped all the way back to his 2019-20 form, but his drop in spin efficiency has coincided with a drop in velocity, and that combination is killing his fastball's run value.
| Year | Velo | Eff. | Whiff% | Value |
|---|---|---|---|---|
| 2021 | 96.7 | 90 | 23.0 | 1 |
| 2022 | 96.8 | 92 | 23.2 | 5 |
| 2023 | 95.6 | 87 | 17.0 | -5 |
Sure enough, Cease's entire production has taken a hit along with it. His ERA rose to 5.58 after giving up seven runs over five-plus innings against the Royals on Monday night for his fourth consecutive non-quality start. It was one thing when he faced the Tampa Bay Rays in back-to-back outings because they're demolishing everybody, but similarly flat starts against the Twins and Royals have put his struggles in starker relief.
The raw number of strikeouts -- 49 over 40⅓ innings -- looks decent, but that's only because he's facing more batters. His strikeout rate has dropped nearly 5 percent without a corresponding drop in his too-high walk rate. Fastballs that find the strike zone get pasted, and since hitters haven't had to treat it like a real putaway pitch, they've been able to fend off the slider a little better this time around, waiting for one that hangs.
The results look familiar, and Ethan Katz's description of Cease's mechanical issues covers old ground, too.
“Dylan was rotating too soon,” Katz said. “He was opening up. He was losing a little bit of his hip/shoulder separation, and … he was pulling his head. So his numbers on his fastball are slightly down, but his efficiency on his fastball is a little bit further down than it has been.”
Cease's velocity did rebound a little bit on Monday, which Pedro Grifol cited, but it's still short of his best. Cease topped out at 97.6 mph, which makes it seven consecutive outings where he hasn't touched 98 mph. That puts him on a pace well behind previous seasons:
- 2021: 211 fastballs 98+ mph
- 2022: 181
- 2023: 4
Of course 2023's total only covers a quarter of the season, but that doesn't help much. If you extrapolate that number through the rest of the season, you'll end up with 16. Unless you extrapolate the number of 98-mph fastball he's thrown since the start of April, and then you'll end up with four. All of Cease's 98-mph fastballs came in his Opening Night start against Houston back on March 30.
Also, Cease's fastest fastball on Monday night got crushed.
Cease still has the arm talent to produce decent results even without an optimized fastball, and the White Sox might've been able to get by with a more ordinary version of Cease if the rest of the rotation compensated with pleasant surprises elsewhere. Alas, Lucas Giolito is the only starter beating expectations. Mike Clevinger is more or less meeting them, but he set that bar pretty low. Everybody else is underwater. Throw in a disappointing bullpen and an offense that disappears against other teams' relievers, and Cease's struggles are just about impossible to hide.
The White Sox are 4-4 in Cease's starts, which doesn't look terrible in isolation. When you see that they're 8-20 over the rest of the schedule, "not terrible" won't cut it from Cease, not at a time when most everything else very much is.
