Profile: Ayumu Ishikawa

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Ayumu Ishikawa shows off his screwball — called a sinker in Japan — notching 10-plus strikeouts for the first time in four seasons on Aug. 20, 2019, vs the Rakuten Eagles.

Ayumu Ishikawa

Team: Lotte Marines

Current status: On Nov. 16, 2020, the Nikkan Sports reported Ishikawa had opted not to ask the team to post him. The pitcher announced on Dec. 25, 2019, he had told the Marines he wished to use the posting system to play in the majors in 2021.

Pos: RHP Birthdate: April 11, 1988. Throws: R

NPB page

Honors: Rookie of the Year (2014)

League leader: ERA (2016) — according to Baseball Lab, Ishikawa led PL pitchers in lowest batting average by opposing left-handed batters (Can you say “screwball”? Sure. We knew you could.)

Ishikawa was the Marines’ top draft pick in 2013. He turned pro after going to university and then playing corporate league ball. He was 36-25 after his first three seasons and on top of the world. But after the 2017 World Baseball Classic, regression to the mean hit him like a ton of bricks.

After his third season, opposing batters got better at laying off pitches outside of the zone, forcing his walk rate to tick up a bit and making him throw strikes a little more often. He went 3-11 in 2017 and from 2018 began throwing a two-seam fastball — a pitch that has something of a cult reputation in Japan after national team hitters struggled against it in the 2013 and 2017 WBCs.

Former major leaguer Takashi Saito, who didn’t throw it in Japan but made a good living off the two-seamer in the States, has said Japan’s tacky baseballs and low soft mounds are not conducive to throwing good two-seamers. It doesn’t help that most of the infields are plastic as well.

Having said that, the mounds in Japan have gradually gotten harder through the use of imported clays, while one team in each league now has one main stadium with a grass infield.

In 2017, Ishikawa introduced a cutter, that according to Delta Graphs has improved with every season. By 2018, he retired his slider in favor of the cutter.

Ishikawa appears to be following a common pattern of pitchers who get better and better results with a secondary pitch and use their four-seam fastball less and less. There are exceptions, but this appears to be a fairly slippery slope, so how things go in 2020 should be educational. Whatever is wrong with the fastball, it’s not velocity. It was more effective when he was throwing it under 143 kph (88.9 mph) than now when he’s throwing it just over 90 mph.

The two-seamer made a resurgence for both Ishikawa and NPB as a whole in 2020. Yudai Ono had tremendous success with it in 2020 — thanks to his precise command and ability to mix it with his four-seamer and breaking pitches, I expect it will become even more popular in 2021.

Arsenal 2020

PitchUsage %Avg. Velocity (kph)Value per 100
Cutter 21.2135.3-.071

Arsenal 2019

PitchUsage %Avg. Velocity (kph)Value per 100

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writing & research on Japanese baseball