Why Sasaki's splitter looks like MLB's next great pitch
David Adler
@_dadlerThe Roki Sasaki splitter is here, and it might be even nastier than we thought.
Sasaki was all-around electric in his Dodgers Spring Training debut Tuesday night, but his splitter was the star of the show.
We already knew the Dodgers were cornering the market on splitters -- between Sasaki, Yoshinobu Yamamoto and Shohei Ohtani, L.A. might have the three best splitters in the world. But the splitter that Sasaki showcased on Tuesday was unique.
And it was basically unhittable. The Reds whiffed on seven of their eight swings at Sasaki's splitter. Only one swing even touched the ball, and that was a lazy flyout. Sasaki collected four of his five strikeouts on the split.
So, Sasaki's splitter is filthy. Really filthy. And the Statcast data shows why.
Here are the three qualities that stood out the most about Sasaki's splitter in his first Dodgers outing:
1) It has extremely low spin
Splitters are a low-spin pitch type. That's what gives them their "tumbling" movement that makes hitters swing over the top of the ball. But Sasaki's splitter is very low-spin.
The Major League average splitter spin rate was 1,302 rpm last season. Sasaki's splitter spin rate on Tuesday was 519 rpm. His four splitter K's came in at 570 rpm, 542 rpm, 403 rpm and 584 rpm.
That's almost like a knuckleball. Sasaki is throwing an extreme spin-killing splitter.
Sasaki threw 18 splitters in his Cactus League debut. In the Statcast era, which goes back to 2015, there have been nearly 2,000 games where a pitcher threw at least that many splitters (or forkballs). Sasaki's spin rate was the lowest of them all.
Lowest single-game splitter spin rate, Statcast era
Min. 18 splitters (Sasaki's # thrown in Dodgers spring debut)
- Roki Sasaki: 519 rpm -- 3/4/25 (Spring Training)
- Emmanuel Ramirez: 577 rpm -- 7/28/24
- Logan Gilbert: 589 rpm -- 6/16/24
- Logan Gilbert: 615 rpm -- 9/19/24
- Mike Pelfrey: 639 rpm -- 5/7/16
Maybe the most intriguing part about this is that it's something of a new look for Sasaki's splitter compared to the 2023 World Baseball Classic. In the WBC, his splitter was more of a true power splitter, averaging 91 mph and around 1,100 rpm. In his first Dodgers outing, Sasaki's splitter sat at 86 mph and in the 500 rpm territory -- slower, but with much more spin killed.
In that respect, Sasaki's splitter more resembled the spin killers currently deployed by the Mariners' star starting pitching trio of Logan Gilbert (640 rpm), Bryce Miller (912 rpm) and George Kirby (946 rpm) than the power splitters thrown by his own teammates Yamamoto (90 mph / 1,326 rpm) and Ohtani (89 mph / 1,287 rpm in his last pitching season, 2023).
But Sasaki's splitter right now is even lower-spin than the Mariners trio. In fact, at its current spin rate, it would be the lowest-spin splitter in the Major Leagues today. The only pitch in 2024 with a lower spin than Sasaki's splitter was Matt Waldron's knuckleball.
2) The drop is ridiculous
There are two results of Sasaki's extremely low spin. One is that Sasaki's splitter experiences an extreme drop off the table.
That can mean either that Sasaki drops the splitter into the strike zone unexpectedly -- he got two strikeouts looking on his splitter against the Reds -- or that he induces chases on splitters that start in the zone but quickly fall out of it. All seven of the swings-and-misses against his splitter on Tuesday were down below the strike zone.
Statcast has two ways to measure vertical pitch movement: the total amount the pitch drops from the pitcher's hand to the plate, which includes the effect of gravity pulling down the ball, and "induced vertical break," which removes gravity from the equation and measures how much rise or drop the pitcher generates himself from how he throws the pitch.
Sasaki's splitter is top-of-the-class no matter which way you measure it.
In terms of total vertical movement: Sasaki averaged 43 inches of drop on his splitter on Tuesday. That is a ton of drop for a splitter. In fact, it's more drop than any splitter in the Major Leagues had last season -- Astros reliever Tayler Scott and the Mets' Tylor Megill with his "American spork" had the most at 41 inches.
In terms of induced vertical break: Sasaki generated five inches of downward movement on his splitters. That would also have been the most in the Major Leagues last year. Scott had the most downward induced vertical break among splitters at four inches, followed by Red Sox starter Tanner Houck at three inches.
So Sasaki's splitter movement is already elite. And we've only talked about half of it.
3) It can break in both directions
This is the other half: Sasaki's horizontal movement. And it gets very interesting.
Almost all offspeed pitches -- splitters, forkballs, changeups, screwballs -- fade to the pitcher's arm side. But Sasaki's splitter moves in both directions.
A lot of his splitters run to his arm-side. But sometimes his splitter cuts to his glove side.
Here's a chart of Sasaki's splitter movement against the Reds on Tuesday:
That's a very wide range of splitter movement from side to side. The running splitters move like his fastball, but with a ton more drop. The cutting splitters look almost like his slider ¡ only they come in harder and with a little less sweep. And all three pitches come out of the same release point.
Going off this one outing, Sasaki seems to like to cut his splitters in on left-handed hitters. Half of the splitters he threw to Reds lefties broke to his glove side -- by as many as six inches -- and those included both of his splitter K's against lefties, vs. TJ Friedl and Carlos Jorge.
Meanwhile, he threw a more "normal" splitter to righties -- eight of his 10 splitters vs. Reds righties had either arm-side or straight downward movement, with a max of seven inches of run on a strikeout of Austin Wynns. But he still cut a couple of those splitters, too, and one of those caught Matt McLain looking at Strike 3.
"He throws it hard. It looks like a fastball," Dodgers manager Dave Roberts said after the game. "Some break straight down, some go to the left. Some go to the right. It¡¯s tough to square it up, because you just don¡¯t know what it¡¯s going to do."
It is very rare for a pitch to be able to do what Sasaki's splitter does. The possibility of his splitter breaking in either direction makes it unpredictable -- which is a trait of the pitch that Sasaki flashed in the World Baseball Classic, too.
The Roki Sasaki splitter looked like one of the nastiest pitches on the planet back then, and after one spring game for the Dodgers, it still looks like that. It looks like MLB's next great pitch.