Let’s Take a Look at Yusei Kikuchi’s First Two Major League Starts

It’s been a whirlwind few weeks for Yusei Kikuchi. Not only did he see his first action as a major leaguer, a well-documented dream of his since his high school days, but his father passed away after a long battle against cancer. He is staying in the United States in accordance with his father’s wish that he concentrate on baseball. It is quite hard to imagine what the young pitcher must be feeling, and we wish for the best for him and his family in this difficult time.

Kikuchi has made two starts for the Mariners. While some data exists from his days in the NPB, MLB presents a new challenge. We can’t reach any grand conclusions about him as a major leaguer yet, but we can make observations and possibly, some extrapolations. At this moment, here are the basic numbers: 10.2 innings pitched, five hits, three earned runs, two home runs, eight strikeouts, and one walk. Kikuchi currently has a 2.53 ERA and a 4.25 FIP. It’s too early to make any calls, but Seattle has got to be pleased with the return so far.

Our analysis of this limited sample becomes trickier because we only have Statcast data for one of his starts. His Tokyo start – you know, the one where Ichiro announced his retirement mid-game – is not registered there because the Tokyo Dome isn’t equipped with Trackman or PITCHf/x cameras. So, we have his 91-pitch start against the Red Sox on March 29, which is quite a small sample to work with. Kikuchi’s tendencies could change as he pitches in the majors and adjusts to either his strengths or hitters’ weaknesses (or both). With those the caveats understood, his early efforts still merit examination.

Let’s start with the obvious here: the fastball. Since he was an acclaimed prospect at the Hanamaki Higashi High, Kikuchi has been known in Japan for his fastball velocity. In 2017, he set what was then an NPB record for the fastest pitch recorded by a left-handed pitcher with a 158 kmph (roughly 98 mph), though it should be noted that his average fastball velocity was 148.6 kmph (around 92.3 mph). In 2018, his velocity slipped a bit. According to Delta, an NPB sabermetrics site, it went down to 147.3 kmph (around 91.5 mph) last year. He suffered shoulder tightness that was later diagnosed as decreased functionality of shoulder last year, so that seems to have played a part in the decline in velocity. Of all his pitches, the fastball is the only one that Eric Longenhagen and Kiley McDaniel did not describe as above average in their write up of Kikuchi for in this year’s top 100.

Against the Red Sox, Kikuchi averaged at 93.1 mph. Statcast had him as high as 95.4 mph. It is not Ohtani-esque big velocity, but it is a range that should work in the majors, especially if he can maintain it through starts consistently locate it like this:

By average velocity, he’s comparable to the likes of David Price and Sean Newcomb. Maybe he’ll gain a tick or two as the season goes on or maybe he’ll get worn down. I don’t know. But as far as the velocity goes, Kikuchi can say he belongs in the majors. One thing of note is that his fastball only induced a whiff once out of the 43 times he threw the pitch. Statcast measured the pitch’s average spin rate at 2,173 rpm. According to Travis Sawchik, an average fastball around 93-94 mph measures out to 2,240 to 2,300 rpm. At least for that one start, his fastball was not seen to be a swing-and-miss weapon, as his velocity would indicate. Obviously, Kikuchi has arm strength, but not all 93 mph fastballs are created equally. Luckily for him, he has another tool in his toolbox that drew many more swings-and-misses: his slider.

Kikuchi’s slider features a nasty 10-5 tilt. He used it as a swing-and-miss pitch in Japan, and he’s used it as one in his early going in the majors as well. Against Boston, he generated seven whiffs from 22 sliders used, which is pretty good! Here’s one to Xander Bogaerts that I feel is representative of how he likes to use the pitch.

And here’s one to Sam Travis that had a particularly vicious bite.

Looking at Kikuchi’s slider heatmap from that game, we see a lot of low and inside pitches to the right-handed heavy Sox lineup. Being aware of his pitch tendencies from the NPB, I’d assume he meant to locate them that way as well. It’s hard to draw a conclusion at this moment, but Kikuchi’s slider has been rated above-average, as noted by Eric and Kiley. Future value grades don’t always come to fruition, but I would say that Kikuchi’s slider could forecast well in the majors.

As for the bad, Kikuchi did not necessarily avoid the meat of the zone. Here is his pitch heatmap:

The good here is that Kikuchi located well to the inside edge versus right-handed hitters, and away versus left-handed hitters. However, there’s that big dark and red circle towards the middle-up part of the strike zone that indicates that he was also prone to leaving pitches “up there.” FanGraphs rated his command as a 45-grade, which is just below major league average. As of this moment, Kikuchi has thrown 64% of his pitches for strikes and allowed only one walk in 10.2 innings pitched. Those are good control numbers. Command is a different thing. The Red Sox hitters were much less than forgiving on Kikuchi’s mistake pitches.

Here’s J.D. Martinez going yard on a fastball right down the middle. The catcher had his glove up and in, but the ball missed the spot and Martinez drove it over the center field fence.

Here’s another home run allowed, this time against Xander Bogaerts. The explanation is simple – the catcher appears to have wanted it down and away but the fastball went right down the middle, which is likely to be punished by many major league hitters.

Pitching is extremely hard. You must stand a mark and locate each pitch into a glove size smaller than a pie tin from 60 feet 6 inches away. But it’s also the nature of the business – if you miss even so slightly, major league-caliber hitters can hit it a long way. It is worth noting that every pitcher makes mistakes. It’s the matter of minimizing the amount of them. There will be days when Kikuchi will makes fewer mistakes, and there will probably be days he makes more.

What’s curious for now is that Kikuchi has noticeably bumped up his curveball usage. Here’s the chart of his March 29 start versus his 2018 pitch data with the Seibu Lions, thanks to the NPB sabermetric website Delta.

It’s an interesting bump. He never threw his curve more than 11.1% in a season with the Seibu Lions. He was known for his fastball/slider mix in Japan. The curveball, according to multiple scouting reports, was a third pitch that he would use to give different looks. And it’s not just his start against the Red Sox either. Over at Lookout Landing, Jake Mailhot recorded Kikuchi’s pitch data by hand during the Athletics game in the Tokyo Dome. The chart below indicates that Kikuchi has shown very similar pitch mix for his first two starts as a big leaguer.

One theory on why Kikuchi increased his curveball usage lies in data. Last June, Jim Allen of Kyodo News wrote on how Kikuchi relies on data to make adjustments to things like his release point and extension. I’m not sure how much attention he puts on his pitch metrics, but his curveball does grade out well on Statcast. Take a look at his pitch data from Baseball Savant:

Not only does an effective curveball give hitters another thing to worry about, but the velocity difference can also make his heater stand out more. Here’s a curveball that he threw to the reigning AL MVP Mookie Betts. Betts reacted like he was not expecting this pitch. He held up a for a microsecond and got his bat head out, but made weak contact that ended up being a groundout.

He didn’t generate any whiff with the pitch, but it induced two bits of weak contact for an overall .124 xBA. He also used it to get ahead in counts. Out of 18 curves thrown, nine of them were called strikes. Here’s one of them to Betts.

Kikuchi has had two decent starts and the pitch has worked well, so I don’t anticipate him making drastic changes anytime soon. It will be something to monitor, though. History has shown that many successful pitchers – Tanaka, for instance – have demonstrated the ability to modify their approach to survive in the majors. As time goes on, major league teams will have a book on how to approach Kikuchi. Once they know better what to expect, I don’t know how successful they’ll hit against him, but surviving in the majors involves series of adjustments. If Kikuchi runs into a harder time getting hitters out, I would expect him to take a different approach.

Lastly, it’s worth noting that Kikuchi seemed to struggle when facing the order the third time around. In a very small sample, Kikuchi faced five batters a third time through the order between the A’s and Red Sox games, and allowed two hits, including that aforementioned JD Martinez home run. Again, it is hard to draw conclusions out of five-batter sample, but the concern is not unfounded. The lack of a big fastball could become a problem late in games in instances where he struggles to give hitters different looks. As Bill Petti has written for FanGraphs about how pitchers with a big fastball — who can maintain that velocity late in games — are more likely to pitch deeper.

There will be so much more Kikuchi to watch. Personally, I’ve waited for awhile for him to arrive to the majors, as I’ve written about the lefty a couple of times in the past. Two starts in, Kikuchi gave his team a real chance to win on both occasions. For a starting pitcher, there’s not a lot more you can ask for.