BA Subscriber Mailbag: Is Roki Sasaki Best Pitching Prospect In The World?

Baseball America editors and writers are answering the questions posed by Baseball America subscribers, as posted in a BA subscribers’ mailbag. If you want to read the responses and ask your own questions, subscribe here.

---

Zak from Boston asks:

If Roki Sasaki was playing in the MiLB, would he be considered the best pitching prospect right now?

This is a great question Zak. I believe the answer is yes, and I’d go further. I believe Sasaki, ace of the Chiba Lotte Marines, may soon be the best prospect in the world, if you define a prospect as someone who has not lost MLB rookie eligibility.

Pitchers are generally riskier than hitters—their performance varies more and they have a higher risk of injury. Because of that it’s hard for a pitcher to be the No. 1 prospect in baseball at any point. But Sasaki is showing that he could potentially step into the majors as a front-of-the-rotation ace.

Let’s start with comparing him to the best pitching prospects in the game. Grayson Rodriguez currently ranks as the top pitcher in our Top 100 Prospect rankings. The 22-year-old has done nothing so far this year to change that assessment, as he’s toying with Triple-A hitters. Rodriguez has a chance to have three 70 pitches eventually thanks to his fastball, slider and changeup and he’s demonstrated plus control.

As good as Rodriguez’s fastball is, Sasaki’s is a little better. It’s reasonable to call it an 80 pitch. He can sit 99-100 mph and reach back for 102 when needed. It has the kind of carry in the top of the zone that generates plenty of swings and misses. And he’s shown that he can locate it to all four corners of the strike zone.

Sasaki’s best secondary offering is a top-of-the-scale splitter/forkball that pairs extremely well with the fastball. It’s an 88-93 mph pitch that hitters often swing over and never square up. 

Often the splitter can be negated if hitters can recognize it. It becomes an automatic take as hitters can usually count on it diving out of the zone. Sasaki doesn’t just bury his splitter. 

Instead he works at the very bottom of the zone at times, stealing strikes if a hitter is looking to take. He’ll even elevate it up in the zone. While that would seem to be counter-intuitive, it’s worked for him this year as hitters will swing over it and foul it off, and it looks enough like his fastball to mess with their timing.

 

This season, he’s thrown it for strikes 72% of the time, getting swings and misses 67% of the time. Yes, the NPB is not the majors, but in comparison, Kevin Gausman got swings and misses on his splitter 46% of the time last season.

To say that it’s proven unhittable this year is an actual fact. He’s thrown it 149 times this year. Only one batter (Shingo Usami) has hit it out of the infield—he drove a fly ball to right field. Another 11 batters beat the splitter into the ground for ground outs. Four others grounded into double plays while 38 struck out. Currently hitters are hitting .000/.054/.000 against it this year.

Sasaki also throws an 87-91 mph slider that is an above-average pitch thanks to its power. Every now and then he’ll mix in a slower and bigger, 78-81 mph curveball. Its shape isn’t all that impressive, but when hitters are gearing up to try to hit 100 mph, the surprise factor of a pitch that is 20 mph slower is quite effective. Of the 10 he’s thrown this year, only twice has a hitter even swung at it and no one has put one in play.

In his first five starts this year, Sasaki has faced three-ball counts only 17 times. In comparison, hitters have faced two-strike counts 154 times. Rodriguez has 11 three-ball counts and 62 two-strike counts.

Sasaki is only 20 years old. That can be viewed as a benefit or a drawback for him. He was one of the stars of Japanese high school baseball and this success has long been anticipated, but his dominance this year is a significant jump in both stuff and effectiveness when compared to 2021. Last year, he topped out at 98 mph and sat 95. This year he’s sitting 98-99 and topping out at 102 mph. That has made his fastball and everything else play better.

Sasaki only has 16 NPB starts, so his track record of pro success is quite brief. And his dominance this year (3-0, 1.50 with just 13 hits in 36 innings with five walks and 60 strikeouts) is measured over an even shorter span.

But many Japanese aces over the years have demonstrated that exceptional stuff in Japan translates quite well in a trip to the States, and Sasaki’s stuff is as good as pretty much any Japanese pitcher who made the jump to the U.S.

Does that make him the theoretical No. 1 prospect in the world? Maybe not right now, as Adley Rutschman has a higher floor than a 20-year-old pitcher who throws as hard as any starting pitcher in the world (Jacob deGrom, Jordan Hicks, Hunter Greene and Shohei Ohtani are his only real competition for that title).

But with Rutschman likely to graduate this year and Julio Rodriguez and Bobby Witt Jr. expected to graduate even sooner, there is a pretty good case that Sasaki may soon be the best prospect in baseball, even if he likely won’t be eligible to wear that crown for a number of years.