Yesterday’s rough outing by Yusei once again raised an important question: what the hell is going on here?
It’s tempting to look at the league-worst FIP, his drop in strikeouts, and his home run rates and say “everything” is what’s wrong with Yusei Kikuchi.
I mean, look at this chart. These colored lines are going in precisely the direction you do not want these particular colors of lines to go.
It’s also tempting to look at the context surrounding Kikuchi’s first ML season—the death of his father, the birth of his child, the first year in the MLB, the new schedule, the new ball—and say “nothing” is really wrong with Kikuchi. That it’s all a learning curve and a product of environmental factors that will be tuned up next season.
The truth about what’s wrong with Kikuchi is somewhere between “everything” and “nothing.” The issue with Kikuchi is that he can’t repeat his delivery.
Here is a photo of Kikuchi’s release points from this season.
Here is a photo of an average pitcher’s release points.
Sure, release points vary start to start, even throughout a game—throwing a baseball the same way is hard. But we have numbers that tell a woeful story.
This is RelDist. RelDist is the release distance between pairs of pitches—meaning where the ball is released from the pitcher’s hand relative to other pitches. In the chart we see all of Kikuchi’s measured pairings. The average RelDist for a pitcher between any pair of pitches is 2.6 inches of separation. No pair of Kikuchi’s pitches is under 3 inches, and the curveball and slider are released at a shocking six inches apart.
What does six inches of separation look like to a hitter? It looks like yesterday’s start.
The curveballs might as well be formally introduced over the PA before release for all the difference it would make—which is part of the reason why hitters have an expected wOBA of .423 against the pitch, making it both his worst and one of the worst in baseball. This wouldn’t be terrible if Kikuchi didn’t throw the pitch 22% of the time. But he has to throw it. He needs a third pitch to make it through the lineup more than one time.
We see this inconsistency of release points to an extreme between starts.
Here are the release points mapped from Kikuchi’s best start of the year—his scoreless gem against the Indians.
Now, compare that to the less-than-stellar July 14th game against the Angels.
While the cluster is smaller, notice the shift from the right side of the 2ft mark, to the left. And the three inches of drop? From one start to the next he threw out of an almost an entirely different arm slot.
What effect does an inconsistent release have on a hitter? Let’s visualize this for a moment.
This is what a hitter sees when Kikuchi pitches—three distinct pitches. The first balls near release are called the “Recognition Point” or the point at which a hitter recognizes the pitch out of hand. The closer set is the “Decision Point” which is the point of flight when a hitter decides to swing. That is the critical point. If you’ve ever watched a Pitching Ninja overlay you know how nasty it looks when two pitches mimic one another up until the decision point. This is what we refer to as “tunneling.” For a refresher, Baseball Prospectus has an easy to decipher feature on pitch tunneling.
For Kikuchi, his pitches are for the most part easily separated and categorized by hitters at release, recognition, and decision.
To the numbers!
PreMax measures the distance between back-to-back pitches at the decision making point. The average distance between MLB pitches is 1.54 inches of separation at decision, and obviously the less distance the better for a pitcher.
Kikuchi comes out better using this tunneling metric than for release, especially his slider and fastball pairings to right handers, but notice that any pairing involving a curveball is decidedly below average. Even when he throws back-to-back curveballs! His curveballs don’t even tunnel with curveballs!
OK—so Kikuchi’s release point wanders and his pitch tunneling isn’t great unless he’s throwing a fastball and slider to a right handed hitter. You would assume that this inconsistency would also result in an inconsistency of strikes.
Oddly, Kikuchi actually leads all of major league starters in pitches thrown in the strike zone. No one throws more strikes than Kikuchi. The issue is that, likely because of his release and poor tunneling, he ranks ranks 73rd out of 75 qualified starters in getting hitters to chase pitches out of the zone. If a hitter can recognize a pitch out of the hand, and see separation at the decision point, it allows him to be more selective. Hitters only really have to worry about a fastball or slider sneaking up on them, and even those they can recognize.
None of what we discussed so far is good news. The final thing we want to know as fans of this baseball team is whether or not this is a forever problem or a right now problem. The Mariners plan to compete in 2021, Kikuchi is a big part of that calculous.
I believe there are likely two main issues that need to be addressed.
This clip is beautiful. I loved it in spring. Now, though, when I watch Kikuchi’s delivery all I see are a series of intricately related moving parts with so much that can go wrong. Particularly how he has to whip his arm so late through his motion because of how he hides the ball. It doesn’t look like a delivery that is easy to repeat. Apparently, it isn’t.
The coaching staff is well-aware of the problems his delivery poses, and every indication is that they are working on it.
“He has a delivery with a hesitation when he comes to a set point,” Dipoto said in an interview with 710. “That makes it a little tougher to create rhythm and flow as our pitching coaches work with him.” The amount of moving parts makes adjustments difficult, as it does when Kikuchi insists on “tinkering” with his delivery. Whether this is fixable depends on Kikuchi and the coaches, but there is almost no precedent for changing a 27 year olds pitching motion. This is who he is, they just need to maximize it.
Issue #2: Fatigue.
There is not much to say about this that hasn’t already been said, but the plan was always to limit Kikuchi’s innings by allowing him a few rest starts throughout the season as he transitions to a different throwing schedule. That has more-or-less happened with 107 innings spread over 21 starts (though it’s still a decent workload). The team is taking an abundance of caution given his previous injuries and the history of NPB to MLB arm issues. Wearing down mentally and physically, which Kikuchi wouldn’t be blamed for experiencing, would also make repeating complex mechanics even more difficult from start to start. Fatigue is likely fixable with repetitions, so long as it isn’t a nagging injury keeping him from repeating his delivery (this is not a jinx).
So, Kikuchi cannot repeat his complex mechanics consistently and his curveball is essentially being thrown from a different arm slot, leaving him with two pitches. Not great.
There is, though, a glimmer of hope: the changeup.
Recently, Shannon Drayer reports that the coaches have encouraged him to use his changeup more.
While he often has difficulty locating it and he has thrown exactly one (1) to left handed hitters, the pitch tunnels well to RHH and it has alleviated a major issue: Chase %.
It’s been his best pitch, though rarely deployed, and hitters have been chasing it out of the zone half the time it’s thrown.
When it comes to Kikuchi, if you want to weep for the future of the franchise there is reason to do so. Just go back and look at the wandering release points, the complex mechanics, and the worst-in-all-of-baseball-I-can’t-believe-it results.
If you want hope for the future, you can find that, too. Just look at the emergence of the changeup, the zone rate, the action on his slider, and the myriad of personal tragedies and hardships he has endured this year.
Next year, and the year after, the Mariners are supposed to find a window into contention, and the team is counting on Kikuchi to help pry it open. Will he be able to make the adjustments? Will he get his career back on track? Will the coaching staff be able to help Kikuchi be the player he wants to be? That the team needs him to be?
Projecting the future is always a leap of faith. I guess we’ll see where he lands.