Kodai Senga

Profile: Kodai Senga

Every year, Hawks ace Kodai Senga asks his team to post him and is 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. Provided he is fit enough to stay on the active roster for three months next season, Senga will be eligible to file for international free agency after the 2022 Japan Series.

Updated: Nov. 21, 2021

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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.

Team: SoftBank Hawks

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

NPB page

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)

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.

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

He also threw a sinker this season and a curve, but not often

Senga’s fastball is now among the hardest-thrown in Japan, with only a few of the hardest-throwing imported relievers averaging more speed with it. The biggest problem with the fastball is location. Those days when he can locate are basically wins for the Hawks because no one is going to be able to handle that as well as the cutter and splitter.


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. The numbers below are how a pitcher rates in Japan among the pitchers who threw at least 10 of that type of pitch in the season. They are rated by how often they are strikes, how often they are located on the corner, and how often they are missed.

  • Fastball: Strikes 65% +0.9 SD, Corner 5%, -3.1 SD, Miss 7% +1.5 SD, Grade: 60.
  • Cutter: Strikes 65% +0.1 SD, Corner7% -0.5 SD, Miss 11% +0.2 SD Grade: 50
  • Split: Strikes 57% -2 SD, Corner 6% +0.1 SD, Miss 28% +4.2 SD Grade: 70
  • Slider: Strikes 54% -3 SD, Corner 7% – 1 SD, Miss 5% -3.8 SD Grade: 40

The slider’s value appears to be more as a surprise pitch from a guy who throws hard with a really good tumbling splitter. The fastball could rate higher if he locates it consistently. Although as the video below, a quiz asking viewers to identify which pitches are splitters and which are sliders, shows, that dropping slider can be a good pitch.


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