Mike Petriello of MLB.com recently wrote an article highlighting the increase in splitters around the league. There were 27 starting pitchers who threw at least 10 splitters in 2023, with 16 of them throwing the pitch at least 10 percent of the time.
For context, 17 starting pitchers threw a splitter in 2022, with 13 using it 10 percent of the time or more. In 2021, 20 starting pitchers threw a splitter more than 10 times, 15 of which threw it over 10 percent of the time. The number of starting pitchers using splitters grew, and those that threw the pitch used it more often.
With that, we'll look at a few pitchers throwing splitters. How does it fit into their arsenals? Should they continue using it, and does the pitch mean we should target them in drafts?
Chase Silseth
After throwing a splitter 27.3 percent of the time in 2022, Chase Silseth lowered its usage to 16.7 percent in 2023. Surprisingly, or unsurprisingly, Silseth's splitter also jumped in swinging-strike rate from 13.9 percent to 18.5 percent. Besides the swings and misses, his splitter generated better results, most notably against left-handed hitters, who managed a .224 wOBA off the pitch in 2022 compared to a .304 wOBA in 2022.
In August, Silseth bumped his splitter usage to 28.2 percent, peaking right around its 2022 usage, as seen below:
Be mindful that Silseth went in and out of the rotation and up and down from Triple-A due to injuries and
Mike Petriello of MLB.com recently wrote an article highlighting the increase in splitters around the league. There were 27 starting pitchers who threw at least 10 splitters in 2023, with 16 of them throwing the pitch at least 10 percent of the time.
For context, 17 starting pitchers threw a splitter in 2022, with 13 using it 10 percent of the time or more. In 2021, 20 starting pitchers threw a splitter more than 10 times, 15 of which threw it over 10 percent of the time. The number of starting pitchers using splitters grew, and those that threw the pitch used it more often.
With that, we'll look at a few pitchers throwing splitters. How does it fit into their arsenals? Should they continue using it, and does the pitch mean we should target them in drafts?
Chase Silseth
After throwing a splitter 27.3 percent of the time in 2022, Chase Silseth lowered its usage to 16.7 percent in 2023. Surprisingly, or unsurprisingly, Silseth's splitter also jumped in swinging-strike rate from 13.9 percent to 18.5 percent. Besides the swings and misses, his splitter generated better results, most notably against left-handed hitters, who managed a .224 wOBA off the pitch in 2022 compared to a .304 wOBA in 2022.
In August, Silseth bumped his splitter usage to 28.2 percent, peaking right around its 2022 usage, as seen below:
Be mindful that Silseth went in and out of the rotation and up and down from Triple-A due to injuries and inconsistencies. He's not yet a finished product, but Silseth also has a slider that elicits whiffs, with a 13.7 percent swinging-strike rate. He uses his slider mostly against right-handed hitters (29.5 percent), with a .243 wOBA. Silseth's slider consistently boasts some of the best vertical movement in the league, ranking second among right-handed sliders with 8.6 inches more drop than the average slider.
Early 2024 Outlook
The early ADP market isn't sleeping on Silseth, with a Draft Champions pick of 330. Silseth goes near a mixed bag of pitchers, including starters like Dean Kremer, Chris Paddack, Logan Allen and Paul Skenes and relievers like James McArthur and Will Smith. It's worth taking a shot at Silseth at his ADP given that he has two non-fastballs that generate whiffs, especially his splitter.
Logan Gilbert
The ADP market loves starting pitchers on the Mariners, including Luis Castillo, Logan Gilbert and George Kirby. Seven out of the 11 Mariners drafted in the top 300 are pitchers, showing how the market is prioritizing them.
Last season, Gilbert introduced a splitter after mainly throwing a four-seamer, slider and curveball, a trio which accounted for over 90 percent of his arsenal in 2022. Gilbert's splitter gave him a second pitch that earned swings and misses in addition to his slider, which has a 15.8 percent swinging-strike rate for his career. Some fantasy managers may have avoided Gilbert last year because he only had one pitch with a swinging strike rate above 11 percent in the slider.
As seen above, opposing hitters have been crushing Gilbert's four-seamer, especially right-handed hitters. Thankfully, Gilbert's slider bounced back from a swinging-strike perspective. It made me question what happened to Gilbert's slider. Well, it changed:
Gilbert threw his slider a little harder than in 2022, by slightly more than one mph, and its spin dropped by over 200 RPM, as seen above. That caused the slider to drop nearly three more inches than in 2022. That typically means more whiffs, which occurred, explaining why the pitch bounced back swinging-strike rate.
One final interesting note on Gilbert's slider before discussing how that fits with his splitter. Gilbert threw his slider in the zone 56.1 percent of the time. That's over 11 points higher than league average, and his slider ranked first in zone percentage among all sliders thrown. So Gilbert pounds the zone and generates whiffs with his slider, a lethal combination to pair with a splitter that causes hitters to chase and whiff.
Gilbert lowered his four-seamer usage, dropping it 12 points while increasing his slider by five percentage points. The splitter ate into the four-seamer usage, as he used the off-speed pitch 14.8 percent of the time. Throwing fewer four-seamers made sense since the pitch hasn't fared well against either side of the plate:
Gilbert should continue using the splitter to avoid potential platoon splits. His splitter provides him with a second quality offering against lefties (.212 wOBA) and righties (.233 wOBA) to go with his slider. It also generates a high swinging strike rate for righties and lefties, as seen in the visual above.
Early 2024 Outlook
Gilbert and Logan Webb share many qualities as innings eaters with similar skills and are going within a pick in ADP, so take your pick there. We have several reasons for optimism to buy Gilbert at his current ADP, especially as he potentially possesses two swing-and-miss offerings. Gilbert's splitter looks like a legitimate and reliable pitch to bank on in 2024.
Zack Littell
A commenter on my most recent article, which covered four pitchers who should throw a seldom-used pitch more often, asked about Zack Littell as a potential sleeper in 2024. That led me to research Littell and notice his splitter usage and effectiveness. After joining the Rays, Littell performed well as a starter and a reliever, with a 16.4 percent strikeout minus walk rate.
He showed elite control numbers, with the eighth-lowest ball rate (31.3 percent) among starting pitchers with 50 innings. That gives Littell a high floor, given his ability to limit walks. Littell flashed average to above-average strikeout skills, mainly via his splitter, which had a 16.1 percent swinging-strike rate.
He used his splitter against lefties (31.2 percent usage) at a similar rate to his four-seamer (31.4 percent), as seen above. It's a small sample, but the splitter allowed mediocre results (.306 wOBA) against lefties. Results aside, we should expect Littell's splitter to continue generating whiffs based on its movement profile.
Before we close out Littell's tab, let's highlight that added a sweeper in July 2023. His sweeper doesn't generate swings and misses, evidenced by its 9.5 percent swinging-strike rate. That's likely due to his low zone percentage (21.4 percent), meaning hitters have been able to lay off the sweeper. If Littell throws his sweeper in the zone more often, it possesses above-average vertical movement, giving him a slower slider that drops and potentially elicits whiffs.
Early 2024 Outlook
In the early Draft Champions ADP, Littell goes around pick 380, near Garrett Whitlock, Jack Flaherty, Graham Ashcraft, Bryce Elder and Josiah Gray among starting pitchers. Littell might not have the upside and electric stuff of past breakout Rays starters like Drew Rasmussen and Zach Eflin. However, there's enough to dream on with Littell as a sleeper starting pitcher going right inside the top 400 picks.
Keaton Winn
Keaton Winn made 14 starts for Triple-A Sacramento last season, with a 15.2 percent strikeout minus walk rate. Control may be an issue, as he hovered around a league-average ball rate of 36.3 percent. However, in the small MLB sample of 42.1 innings, Winn had a 32.2 percent ball rate. It's safe to expect something in between for league-average control.
Let's get to what we came here for: Winn's splitter. His splitter was the only non-fastball thrown over 55 percent of the time among starting pitchers who threw at least 100 pitches. The next closest non-fastballs (counting only four-seamers and sinkers as fastballs) were Corbin Burnes' cutter (54.5 percent) and Jakob Junis's slider (53.1 percent).
Winn's splitter rivaled Kevin Gausman's while besting it in swinging-strike rate (26.4 percent vs. 22 percent). Interestingly, Winn threw his splitter in the zone 46.6 percent of the time, over 20 points higher than Gausman. That's notable because it means Winn can generate whiffs while keeping the splitter in the zone at a high rate (10 points above the league average).
Early 2024 Outlook
Unfortunately, Winn's fastballs struggle against both sides of the plate. Against righties, Winn uses his sinker 24.8 percent of the time, allowing a .309 wOBA and .390 xwOBA. He uses his four-seamer the second-most often (39.4 percent) against lefties, with a .552 wOBA and .447 xwOBA. The four-seamer possesses above-average fade, potentially leading to more weak contact over a larger sample. Winn needs a reliable second offering in the four-seamer or sinker to balance his deadly splitter. Take a flier on Winn as a late-round sleeper going around pick 424.
