What Went Wrong: Dylan Cease

White Sox ace Dylan Cease is coming off of a 2023 season that has left a sour taste in the mouths of many fans. Sure, he had a 3.72 FIP and the 18th-best fWAR among starting pitchers (better than the likes of Corbin Burnes, Luis Castillo, Justin Verlander and just shy of Cy Young hopefuls Blake Snell, Aaron Nola and Kyle Bradish), but a 6% below average 4.58 ERA better represents what the casual fan feels like they observed.

For a 101-loss club, Cease’s 3.7 fWAR season is a drop in the ocean-sized bucket of issues that we all sat back and watched this summer. Despite his inflated ERA (a stat that does a lousy job at summarizing how a pitcher performed over a single season given the myriad of other stats and metrics at our disposal in 2023), Cease put together a very respectable season. However, 2023 undoubtedly represented a step back from a second-place Cy Young finish just a year earlier, and I was curious about what exactly went sideways.

Cease spent three years in the Cubs organization prior to being traded to the South Side in 2017. He was viewed as a very high-ceiling prospect with electric stuff, but also with control issues that had some evaluators projecting the bullpen as his eventual home. He’s one of the few cases since the rebuild started in December 2016 that improved upon entering the organization and has had sustained success. Cease did so immediately in 2017, and then again in a breakout 2021 season after struggling through his first two in the majors.

I consider 2021 to be Cease’s breakout, with 2022 serving as a representation of additional progression. A similar progression in 2023 would have placed him comfortably in the Top 5 pitchers in the sport, but instead he regressed. Some of the blame falls on his shoulders, while some of his struggles can be attributed to his supporting cast.

The first thing that stands out when comparing Cease’s surface-level stats from 2022 to 2023 is his BABIP shooting up from .260 to .330. It was the highest in MLB among qualified starting pitchers in 2023. But how much of that can we attribute to Cease giving up harder contact vs. the White Sox consistently putting a below-average defense behind him?

Cease’s .247 BAA underperformed his .238 xBA (57th percentile) and similarly his .321 wOBA underperformed a .311 xwOBA that was the 37th-best in the league among the 100 pitchers who faced 500 hitters in 2023. This points to bad luck — and a shoddy defense failing him.

Chicago’s fielders ranked 19th in Defensive Efficiency (.701), 25th in Outs Above Average (-17) and 29th in Defensive Runs Saved. Woof.

Cease had a 39.1 Fly Ball% (63rd Percentile), which was the lowest of the White Sox Opening Day starting rotation. In fact, each of Lucas Giolito, Lance Lynn, [redacted] and Michael Kopech were all in the Top 25 among starting pitchers in Fly Ball% (the second-highest as a starting staff in total), traits that these pitchers have displayed throughout their careers. Yet the team put the 22nd-best outfield defense (by OAA) behind them; that seems like a suboptimal strategy.

Zoning in on Cease’s contact quality, we see that his Barrel% actually stayed exactly the same in 2023, at 6.2 (78th percentile), which is a very good value. The issue is that his Hard Hit% rose from 31.2% to 41.5%, putting him in the bottom third of the league. Increases in other more in-depth contact quality metrics like Sweet Spot% (batted balls hit at optimal launch angles), EVFBLD (average exit velocity on fly balls and line drives), and DHH% (Dynamic Hard Hit%) confirm that hitters made better contact against Cease, along with more contact overall.

Why is that?

I first examined Cease’s pitch usage, and that unveils that he threw his slider — the pitch that was literally the single best pitch in baseball in 2022 by Run Value — less frequently in 2023. He opted for more fastballs, even though his slider-heavy approach worked so well in 2022.

Ironically, if we flash back to last offseason, we were reflecting on Cease drastically changing his usage profile. In 2021, Cease threw his heater just less than 47% of the time, with his slider used 31% of the time. With the slider thrown at a 50% Whiff rate (16% better than league average), Cease and pitching coach Ethan Katz determined that the next step in turning Dylan into an ace was throwing it a hell of a lot more, and he did so in 2022. Cease upped his slider usage to 43% (throwing it more than his fastball) and enjoyed a 43.3% Whiff rate with a minuscule .128 BAA (.144 xBA) and a .187 wOBA (.201 xwOBA). It was an optimized arsenal deployment, and it worked wonders.

In 2023, Cease dropped his slider usage to 38.6%, and its BAA rose to .216 (slightly better than .221 league average), yet he maintained the exact same Whiff rate (43.3%). Cease’s consistent second half pitch usage solidified his strategy to use the pitch less, and this is likely due to he and Katz noticing the signs of diminished pitch quality.

The success of Cease’s slider in 2022 can be boiled down to pretty simple characteristics. He threw it at almost 88 mph (league average = 85) while maintaining the shape of a traditional slider. As a pitcher, any time you can make your pitches look abnormal in either direction, you’re setting yourself up to be tough to hit. Cease’s slider was a nasty pitch even if you knew it was coming, but when you combine it with a high-ride fastball that averaged 97 mph and at least the threat to flip in a 12-6 curveball or changeup if you’re left-handed, and Cease was not a fun pitcher to face.

In 2023, Cease’s velo was down across the board, which is red flag No. 1. Even if his breaking balls remained exactly the same, a slower fastball (down to 95.6 mph, a significant drop) has compounding consequences throughout the arsenal. The second red flag is that Cease’s slider didn’t remain the same. It was also thrown slower (down 1 mph) and had a shape that was more cutter-ish, meaning more positive vertical break and less of that right-to-left horizontal break that causes right-handed hitters to have nightmares. The pitch displayed less of the abnormal pitch qualities that made it so successful for Cease in 2022.

Cease’s fastball didn’t lose much spin or induced vertical break, which is good. But still, raising your fastball usage while your velocity is down doesn’t seem to make sense — until you realize that his slider was also in flux.

Looking at Cease’s Stuff+, it confirms what result-based stats told us. Each of his four pitch types were worse in 2023, with his fastball representing the lowest drop-off (127 to 125) and his slider representing the largest (a massive drop, from 136 to 120). A 16-point drop in Cease’s slider Stuff+ is a good illustration of the consequences of the velo drop and bad shape change.

Command+ shows that there wasn’t a huge drop with any pitch type, and Cease’s 2023 results didn’t point to any command or control issues. He lowered his walk rate, and threw more first-pitch strikes.

Continuing to tree down to the root of the issues as closely as possible, a glaring detail of Cease’s 2023 season is that his release extension was up two to three inches across the board. He was getting down the mound significantly more, and that seems to be either unintentional, or that it created unintended consequences that hampered his ability to build on his 2022 season.

What this looks like for Cease is some lower-half mechanical issues that he’ll look to clean up prior to 2024, and I’m confident that he can do so to resolidify himself as a bonafide ace. Remember, coming off of his 2020 season, Cease needed mainly do two things to clean up his arsenal: increase his fastball spin efficiency to create more ride on his fastball and miss more bats, and differentiate the shapes and movement profiles of his slider and curveball so that they didn’t blend into one pitch. Cease was able to do both, and it can’t be overstated how much easier said than done these kinds of changes are for a lot of pitchers.

Cease is under contract for another two seasons, but if the White Sox find themselves on pace to be near a .377 winning percentage again as the 2024 trade deadline nears, he could be on the move. He underperformed in 2023, yet still had a good season when you step back and look at his core stats. The 2024 season is only a “bounce-back opportunity” for Cease because of the standard he set for himself in 2022. It also represents an opportunity for Katz, who in any scenario will have his work cut out for him next season, to add value in getting Cease back into the Cy Young conversations.

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