How Kopech can evolve arsenal for rotation move


The changeup wasn’t Michael Kopech’s go-to secondary pitch when he tossed one to Rangers switch hitter Jonah Heim last April. But the pitch faded away from the Texas rookie, inducing a ground ball double play to end the inning and Kopech’s one-run outing.

Plays like that came to fellow White Sox pitcher Lucas Giolito’s mind when after the season he fielded a question about Kopech transitioning from the bullpen to the 2022 rotation.

“He brought the changeup out a few times, and the best ones he threw were just ridiculous,” Giolito said. “… The third pitch is definitely there for him. It’s just a matter of throwing it more and being very comfortable with it.”

While relievers can be effective with two pitches – Kopech this past season relied heavily on his fastball and slider – starters often benefit from a more robust repertoire. More pitches mean more ways to attack a hitter the second, third or fourth time facing him in a game. So, expect Kopech’s pitch usage to shift with his change in role.

Kopech’s debut season provides hints about what he will look like as a starter. The right-hander opted out of the 2020 season and missed the 2019 season after undergoing Tommy John surgery, but in 2018 he started all four games he played. Though it was a small sample size of 14 1/3 innings, Kopech’s changeup (9.8 percent) and curveball (11.3 percent) accounted for about 21 percent of the pitches he threw that season.

Kopech’s pitch mix in 2022 won’t necessarily mirror his approach in his first MLB season. He’s developed since then and is working with a new pitching coach. But Kopech’s 2018 season does show that he’s been comfortable mixing in his changeup and curveball in his career.

RELATED: Giolito: Kopech ‘has the drive’ to join Sox rotation

Last season, when Kopech primarily threw in relief, he threw his changeup (2.6 percent) and curveball (3.5 percent) about six percent of the time. He allowed two hits with each, all four singles. Both pitches had good expected batting averages (curve, .145 / change, .149), but the averages, again from a small sample, didn’t pan out as well in real life (curve, .400 / change, .250).

A full season of regularly mixing in a third and/or fourth pitch will provide a better sense of their effectiveness.

Both Kopech’s curveball and changeup provide another off-speed look, in contrast to his upper 90s fastball. But otherwise, they’re very different pitches. The curve is slower (averaging 79 mph) and dives downward. The change (90 mph) has run to it, moving in on right-handed hitters and out on lefties.

MORE: How the Sox will use Michael Kopech in rotation in 2022

The changeup’s potential against lefties was on display in that April game against Texas, one of Kopech’s four starts and his deepest of the season. And even before Kopech ended his outing with a double play-inducing changeup to Heim, he found success with the pitch.

In the fifth inning, Kopech’s last frame of the day, he gave up a leadoff single. Then, left-handed Rangers hitter Brock Holt stepped up to the plate. Kopech threw four straight fastballs to get to a 2-2 count. Then, with an outside changeup, Kopech caught Holt out in front of the pitch, inducing a ground ball to the right side of the infield and a force out at second.

Next up: Heim.

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