Does Roki Sasaki throw a forkball or a splitter? ... Why not both?

For a while, whether you called it a forkball or a splitter, Roki Sasaki threw one signature offspeed pitch.

You could quibble over what name to give it. You might think that it fit under the broader "splitter" umbrella -- the pitch that Sasaki's fellow Dodgers Shohei Ohtani and Yoshinobu Yamamoto throw so well. Or you might think, with Sasaki's extra-wide split-fingered grip, slower velocity and more unpredictable movement, that it better matched the "forkball" category -- the pitch the Mets' Kodai Senga throws.

But whatever the label, it was the same thing. Since he debuted for the Dodgers last year, Sasaki was throwing one pitch. Until a few starts ago, when he … well, split it into two.

Sasaki is now throwing two clearly distinct versions of his offspeed pitch:

1. The original, slower, extremely low-spin variety he started out with, which can move in any direction, like a knuckleball.
2. A new version (or, old, depending on how you look at it -- more on that later), which is faster, higher-spin and has more traditional drop-off-the-table movement.

He's been doing it for his last three starts. It's a move Sasaki has made to try to stick in the Los Angeles rotation as a starter. And since Roki is evolving, we're also updating our pitch classifications for him over at Statcast.

The original pitch that he was throwing all along with the Dodgers? That's a forkball.

The new, faster version that he's started to use just recently? That's a splitter.

You'll see both pitch types pop up for Sasaki when he takes the mound against the Angels for his Rivalry Weekend start Sunday -- whether you're watching on TV, following along on MLB Gameday or looking for more advanced data on the Baseball Savant Gamefeed.

So what's the difference between Roki's forkball and splitter? Why is he throwing both? Let's break it down.

What does his (original) forkball look like?

Here's the basic Statcast data on Sasaki's forkball for 2026:

• Velocity: 85.0 mph
• Spin rate: 578 rpm
• Vertical drop: 41 inches
• Horizontal break: 3 inches

When has he been throwing it?

The forkball is what Sasaki arrived in the Major Leagues with. It's what he threw for all of the 2025 season, for the Dodgers' World Series run and for his first four starts of 2026.

We'll circle back to this.

What's the deal with a forkball?

The forkball, in general, is a rare pitch in Major League Baseball. Sasaki and Senga, with his "Ghost Fork," are the only pitchers we have as throwing one currently. Regular splitters are much more common. (And even splitters aren't that common, although they are on the rise.)

Even looking at all offspeed pitches, Sasaki's forkball is a unique pitch. He throws it with his fingers "forked" extremely wide apart, which kills the spin on the pitch. His forkball has such a low spin rate -- 578 rpm this season, 492 rpm last season -- that it's almost like a knuckleball. (In fact, Sasaki's forkball has the lowest spin of any non-knuckleball pitch type since his MLB debut.) And it moves like one.

The signature trait of Sasaki's forkball is that it can either run to his arm side, like a normal splitter would, or break to his glove side. His forkball has gotten as much as 15 inches of arm-side run, and as much as seven inches of glove-side break. There are simply very few pitches that have such a wide range of movement.

That makes the forkball an extremely nasty pitch, but it's a double-edged sword, because it's been hard for Sasaki to command. He's had a hard time locating it where he wants to -- either dropping it down below the zone as a chase pitch, or just throwing it for strikes. And Sasaki's erratic command has been his No. 1 issue in the Majors.

But Sasaki throws a regular splitter too?

He does now. In his outing against the Cubs on April 25, Sasaki debuted a revamped splitter. The biggest difference: The new splitter was WAY harder than the old forkball.

Sasaki was throwing his forkball in the mid-80s. His splitter gets up into the low 90s.

He didn't throw the forkball at all in that game vs. Chicago. It was only splitters.

And that splitter is a new pitch?

It is for Sasaki as a Major Leaguer. But it's actually a lot closer to the splitter he was throwing in Japan with the Chiba Lotte Marines, and for Team Japan at the 2023 World Baseball Classic.

In the WBC, Sasaki dominated with a splitter that also sat in the low 90s and just over 1,000 rpm. So when he came to MLB last year, we thought that splitter might be the Majors' next great pitch.

But then Sasaki debuted with the forkball instead. It looked totally different from the splitter we expected.

This "new" splitter, though? The 2026 splitter? It looks a lot more like the old one Roki had before he got here. Sasaki throwing a hard, wipeout splitter isn't new at all. It's a return to his roots from Japan, when he was at his most overpowering.

So how does the splitter compare to the fork?

Here's what Sasaki's new splitter looks like so far:

• Velocity: 90.3 mph
• Spin rate: 1,026 rpm
• Vertical drop: 32 inches
• Horizontal break: 9 inches

The difference isn't just the velo. The split also has about twice as much spin as the fork. The splitter spins at over 1,000 rpm, compared to the 500-ish rpm on the forkball. That makes it move a lot more consistently -- it fades down and away out of Sasaki's hand -- and a lot less knuckleball-y.

Sasaki's splitter, in other words, is now a lot closer to the power splitters thrown by Ohtani and Yamamoto. Those splitters are nasty pitches in their own way: because they look a lot like a fastball and then tumble down beneath the strike zone. They're a lot less loopy than the forkball, and it's hard to hit a 90-plus mph "offspeed" pitch that moves so sharply.

To throw the harder, true splitter with more consistent movement, Sasaki changed his grip. His fingers aren't quite so wide as they were for the forkball, and he switched the baseball from a four-seam to a two-seam orientation.

So Sasaki isn't throwing the forkball anymore?

Not exactly. He didn't throw it in the game where he debuted the new splitter, but in his two starts since, he's reintroduced it.

Now, he's throwing both the splitter and the forkball at the same time.

Sasaki's offspeed pitch usage this season:

• First 4 starts: 31% forkballs (zero splitters)
• April 25 vs. Cubs: 49% splitters (zero forkballs)
• Last 2 starts: 32% splitters, 10% forkballs

Why would he want to throw both?

Roki's splitter and forkball are serving two different purposes, and mixing both of them into his arsenal is making him a more balanced pitcher.

His new, harder splitter is more of an all-purpose pitch. Sasaki can command it better than the forkball. He can either use it to get a strike (his splitter is in the strike zone 44% of the time, compared to 33% for the forkball) or put a hitter away (he's generating a 43% swing-and-miss rate with the splitter and has nine strikeouts with it in three starts, already as many as he has with the forkball all season).

His splitter locations are concentrated either in the strike zone, or straight down below it, which are the two places he wants that pitch to be. The forkball locations are more scattered.

But the forkball has its uses, too. When Sasaki is ahead in the count, the forkball is a real weapon. That's when Sasaki can take advantage of the forkball's unpredictable movement, especially in putaway situations with two strikes where the hitter has to protect.

Of the 20 forkballs Sasaki has thrown over his last two starts, 18 have been when he's ahead in the count. Fifteen have been in either 0-2 or 1-2 counts.

When hitters have to contend with both the diving splitter and floating forkball with two strikes, Sasaki can keep them way more off-balance.

He still has some other major areas to develop, but Sasaki throwing both the splitter and forkball as a combo is an obvious smart move he can make. It's the type of growth we need to see from Roki as a pitcher.