PEORIA, Ariz. – If the first year was about adjusting to a new life in a foreign land that included the birth of his first child, the loss of his father and performing at a level of baseball more difficult than he’d ever experienced, and the second year was about righting all the wrongs of that first year, specifically committing to one set of simplified mechanics to provide consistent velocity, then this third year for Yusei Kikuchi will be about what?

The Mariners hope it will be about the lefty finally reaching the success and potential they envisioned when he signed a four-year, $56 million contract before the 2019 season.

“Even in the sabermetric world, the easiest thing you can do is look at the numbers under the hood to find the most likely breakout candidates,” general manager Jerry Dipoto said. “Whatever of those numbers you look at, if you are a third party who doesn’t watch the Mariners every day or has not seen Yusei Kikuchi, or if you just open up a public site like Fangraphs and dig into what Yusei did last year, he is going to stand out as a potential breakout performer.”

Unflinching in his optimism, Dipoto points to the improvement from 2019 to 2020 in strikeout percentage (16.1% to 24.2%), groundball rate (44% to 52%), home runs allowed per fly ball ratio (18.8% to 9.4%) and fielding independent pitching — a measure similar to earned-run average without the variance of defense (5.71 to 3.30).

And it’s those measures that offset the traditional pitching stats for Kikuchi — a 2-4 record with a 5.17 ERA in nine starts — that look less than stellar.


“Everything that he was doing suggested that he should be experiencing more success,” Dipoto said. “I don’t know that we had a single pitcher that was probably more unlucky than Yusei last year. Some of it was due to a bullpen that didn’t do him a ton of favors with the runners he left on, and some was just luck. I know it’s been an inconsistent couple of years, albeit one truncated season.”

Beyond the sabermetric data, there was also the MLB Statcast data measuring Kikuchi’s velocity and stuff on his pitches that showed drastic improvement. After consulting with Driveline Baseball in Kent and Mariners pitching coaches after the 2019 season, Kikuchi cleaned up his mechanics and shortened his arm swing in an effort to resuscitate the inconsistent velocity and stuff. In his first season, he was a mechanical mess, trying to implement every suggested change or tweak given to him. He would change from start to start and even inning to inning. By the end of that first season, he’d lost any semblance of his original mechanics and his identity as a pitcher.

In 2020, his fastball averaged 95 mph, up from 92.5 mph in 2019, while his cutter/slider averaged 92.1 mph compared to 86 mph in 2019. Of left-handed starters, his cutter/slider was the fastest in all of baseball, while only Jesus Luzardo (95.5 mph) and Blake Snell (95.1) averaged more velocity with their fastballs.

So why didn’t it translate to more success?

It was a lack of command and consistent strike-throwing. Just 51% of Kikuchi’s pitches were strikes. Even worse, he threw first-pitch strikes just 50.5% of the time. By comparison, Marco Gonzales threw first-pitch strikes 64.3% of the time. When Kikuchi did throw strikes, opposing hitters were 10% less likely to make contact than the year before. But he didn’t throw enough strikes and not enough quality strikes for real success.

“Last year, there were many major adjustments,” Kikuchi said through an interpreter. “I was just trying to attack each hitter. I’m just trying to be aggressive.”

Control is throwing strikes instead of balls. Command is making the baseball do what you want and go where you want. At times, he had neither.


The lack of efficiency was a reason he never pitched more than six innings in the season. He would have at least one inning in every outing that would feature 25-plus pitches and ruin his pitch count.

“It’s exactly what happened in a lot of those starts,” manager Scott Servais said. “It was all driven by fastball command. Even though he was throwing extremely hard, it seemed like there was that one inning or that one stretch of the game where he would lose fastball command. You get behind in the count, and now you’re constantly trying to chase it, trying to catch up and get back even in the count and get ahead. Fastball command really dictates how it’s all going to go. We’ve talked about it a lot in the offseason with him.”

Kikuchi’s goals this past offseason mirrored Servais’ goals.

“Gain more control of all my pitches, more command and to simplify my mechanics,” he said.

But there was another aspect to it.

“I worked on the mental side of the game,” he said. “If I were to just have confidence in all my pitches, being able to throw all my pitches in any count. Command often leads to confidence. That was my main focus.”

Will he finally find the success expected?

“We love his stuff, and nobody works harder,” Dipoto said. “There is a lot of underlying information to suggest that a breakout isn’t just possible, but that it’s likely based on what he did last year. Now you still have to go out there and do it, but he has the physical stuff to do it, and I know he’s prepared.”

This season looms definitive for Kikuchi and his future with the Mariners.


As part of his unique contract, the Mariners have to decide if they want him to be a part of the organization for one more season or four more.

The Mariners will have three days after the World Series to decide whether to exercise their club option on Kikuchi, who turns 30 in June. But this club option is a four-year guarantee, encompassing the 2022 through 2025 seasons for a total of $66 million at an annual average salary of $16.5 million, which would then put the total contract at $109 million.

If the Mariners choose not to exercise the club option, Kikuchi would be given a player option year of $13 million for 2022. He could either exercise that option, spending 2022 with the Mariners, or opt out of that final year and head to free agency.

But even a breakout year might not be enough for the Mariners to exercise a four-year club option.