Kodai Senga

Profile: Kodai Senga

Updated: Nov. 1, 2022

For years, Hawks ace Kodai Senga has asked his team to post him and has been politely told to mind his own business because the Hawks as an organization “do not recognize the posting system,” team president Yoshimitsu Goto said in January 2021.

Senga’s principle issues are his command and his fitness. He is a fierce competitor and a personable guy with three above-average secondary pitches to go with his good but unpredictable fastball.

Team: SoftBank Hawks

Pos: SP Born: Jan. 30, 1993. Throws: R

Led the league: Wins (2020), ERA (2020), Strikeouts (2019, 2020), Winning percentage: (2017)

Honors: Best Nine (2), Golden Glove (2), WBSC All Tournament Team:(2017)

NPB page

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Senga missed on turn in the rotation after being deactivated on May 21 with tightness in his right elbow, for which he was again sidelined on June 25 and missed two more starts. He then missed most of August after testing positive for COVID-19.


Senga started spring training in 2021 rehabbing due to issues with both calf muscles, and didn’t throw his first bullpen until Feb. 16, more than two weeks after spring training started.

He was activated on April 6, but was injured in his first game back when he caught a hot smash, but twisted his left ankle and suffered ligament damage when he fell over backwards. Senga returned on July 6, in what was a trial to see if he could join Japan’s Olympic team, allowed a career-high 10 runs, and deactivated.

After pitching in middle relief in the Olympics, Senga returned for the final segment of the season on Aug. 18, and was rock solid the rest of the year as the Hawks tried to battle their way into the playoffs but failed.

The SoftBank Hawks have taken greater advantage from the system of developmental contract players than any other NPB team. Senga is arguably the best player to enter pro ball through that door — the only comparable players would be a pair of former Giants rookies of the year, reliever Tetsuya Yamaguchi and outfielder Tetsuya Matsumoto.

2022 pitches


Senga used his curve and slider a little more in 2022, more than he’d used them in the previous three seasons. According to Delta Graphs, his swing and miss percentage is the highest it’s ever been, while his contact percent was never lower.

HIs fastball is still his most frequent pitch, and the velocity ticked up. Delta Graphs rates it as the eighth most effective heater in Japan among pitchers with 60-plus innings. My measures have it as a little better than median among the 75 pitchers who threw 500 or more fastballs this season.

Delta Graphs measures in runs above and below average, but a pitch that is a little below average is a pretty darn good pitch at this level. In my system, which I’ll use here, the average run value of every pitch thrown in NPB in 2022 was .0275. I’ll also mention his NPB rankings of pitchers throwing each pitch 200 or more times, in value, the percent of pitches missed, and the percent of pitches taken that are called strikes.

PitchPercentAvg. VeloRun per pitch

Senga’s fastball only has average value simply because he misses so often with it. He ranked 111th out of 187 in called strikes. But because he throws it hard, batters do have to be aware of it, and it keeps hitters from sitting on his other pitches.

His forkball was the hardest pitch in Japan to make contact with, and was the 27th best pitch out of the 400 that made the rankings, and the third best splitter — because of his command. It ranks 34th out of 44 in getting called strikes when batters take it.


PitchNPB valueRankedValueMiss PctCalled Pct
NPB Value = Ranking of runs per pitch of the 400 pitches in NPB thrown at least 200 times by a single pitcher; Ranked = No. of pitches ranked of this type; Value = Value ranking among that pitch type; Miss Pct = Ranking among that pitch type of pitches not taken that are missed; Called Pct = Ranking among that pitch type of pitches taken that are called strikes.

2021 pitches


Senga now relies on four pitches: fastball, splitter, cutter, and slider. According to Delta Graphs these rate as follows:

PitchPercentAvg. VeloRun value-100 pitches
Run Values are from Delta Grafs


Pitches are graded 20-80 with 50 representing MLB average, 60 above average, 70 one standard deviation above mean, 80 two SDs above the mean.

  • Fastball: 50
  • Split: 70
  • Cutter: 60
  • Slider: 60


In 2021, Senga’s first pitch half the time was a fastball, and a cutter 22 percent of the time. That changes when he gets ahead with two strikes, when it’s mostly splitter, fastball. When he falls behind, he almost exclusively throws fastballs and cutters. On 3-0, 3-1, batters will likely only see four-seamers.

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writing & research on Japanese baseball