Four months after I gave a scouting report culled with the help of executives and scouts on what to expect from Roki Sasaki—one of them described his ceiling as “best pitcher in the world”—how did the Los Angeles Dodgers righthander measure up to the advance billing in his first outing?

The short answer: Sasaki is as good as advertised. A starting pitcher who throws 98 mph with what looks like the best splitter on the planet will be a force.

The caveat: he is going to need some time to reach that ceiling.

Let’s remember, his outing Tuesday was just a 46-pitch sample and his first time on a game mound in MLB (with a different baseball than is used in Japan). We’re talking first impressions here, folks, not conclusions. Pitching in a Statcast-equipped ballpark, here is what he showed:

Four-seam fastball
Grade: A-

Sasaki averaged 98 mph on 25 four-seamers. That is especially good news for the Dodgers after his average velocity last season dipped to 96.9, down from 98.9 the previous season. One of the major reasons he chose the Dodgers as an international free agent was because he wanted to tap into the Dodgers’ renowned pitching expertise and resources to improve. There appears to be no major change to his delivery, just minor tweaks, such as a slightly deeper bend into his back leg in the gathering phase.

How impressive is 98 mph on a four-seamer? Only 10 starters averaged 98 mph in a game last season with a minimum of 25 four-seamers. Sasaki did it his first time out. That’s an outlier.

So why the minus in the A-minus grade? He appears much more comfortable throwing his fastball to the glove side. He threw only three fastballs to his arm side, resulting in a double, a hit by pitch and a pitch outside the zone that was called a strike. It’s not unusual. Most pitchers naturally get the ball better to one side of the plate than the other. Not a big deal. If it becomes too much of a pattern, righthanded hitters can set their eyes out over the plate. Down the road, I can see him adding a two-seamer.

The oddest part of his fastball is his spin rate. It’s low: 2,022 rpm, well below the major league average of 2,298 and even farther from the average for elite throwers—2,350 for fastballs 96 mph and faster.

Last season, 204 pitchers averaged at least 94 mph on at least 200 four-seamers. Sasaki’s fastball would rank last in spin rate. (MLB baseballs are bigger and less tacky than NPB baseballs, allowing less grip and spin.)

Why does spin rate even matter? The faster a four-seamer spins the more difficult it is to hit (which is how we wound up with the sticky substance era).

Here are the MLB four-seam fastballs last season divided by spin rate. In 200 rpm increments, the distribution in quantity forms a near-perfect Bell curve. The numbers on the far right follow an unbroken pattern: the less spin, the easier the fastball is to hit. Remember, spin typically follows velocity, so faster fastballs are also more difficult to hit.

Sasaki’s heater falls in the slow spin category. Spin rate on a pitcher’s four-seam fastball does not vary much, not without a boost in velocity, anyway (or Spider Tack). Like any other metric, though, it should not be taken in isolation. His velocity and superior movement mitigate some of that low spin. His fastball properties resemble those of Seattle closer Andrés Muñoz, though Muñoz has a spin rate in the average tier (2,256).

Splitter
Grade: A+

Wow. Just wow. Sasaki throws a splitter with the most downward movement and least spin of any splitter in the majors. It’s actually three splitters in one. Like the changeup of Kyle Hendricks, he can make it cut, sink straight or run. To get the baseball to move in three different patterns is even more amazing when you consider it is barely spinning: just 519 rpm, a fraction of the league average for a split of 1,302.

On top of that, the split is floating in there at 85.8 mph, a 12.2 mph separation from his fastball. Hitters simply cannot cover two pitches that far apart, especially when the split drops an absurd 43 inches. No wonder the Reds whiffed seven times on their eight attempts at hitting the Sasaki split. It is the best in show.

Sasaki threw the pitch 42.8% of the time—in a spring training game! There were only 14 regular season games last year in which a pitcher threw such a high percentage of splits out of at least 46 pitches. Hitters, consider yourself warned.

Expect to see hitters hack often at early-count fastballs from Sasaki. No way they want to see that two-strike splitter.

In my November scouting report, I called Sasaki’s splitter a “low-90s divebomber.” The one he threw Tuesday was different. It was about six miles per hour slower and with less spin. He is deadening his splitter more rather than throwing a power splitter like teammate Yoshinobu Yamamoto.

Slider
Grade: C

In my report on his stuff last November, I called his slider “average” while a scout said it was “too slow” with a poor movement profile and will be tightened up by the team that acquires him. It’s still average and the work to improve it has only just begun.

Sasaki threw only three sliders, two of which were non-competitive and the third was a hanger with which he obtained a called strike. It is slow (83.3 mph) with more loop than bite. It’s another pitch with well-below-average spin (1,863 vs. 2,434). Unlike four-seamers, sliders have more room to add spin, depending on grip, release and spin axis. It’s a distant third pitch for him, so average is just fine because the other two pitches are elite. But Sasaki is such a good athlete and has shown such elite touch on his splitter that his slider is bound to improve as the season unfolds.

The Comparison: Logan Gilbert

Sasaki does not have Gilbert’s breaking pitches, but his low-spin fastball/split combo with elite velocity separation most resembles that of the Seattle Mariners ace righthander.