Looking at White Sox' Michael Kopech's momentous improvements

Looking at Michael Kopech's momentous improvements originally appeared on NBC Sports Chicago

Remember Michael Kopech's first start of the season?

He recorded a 13.50 ERA to kick off his season against the San Francisco Giants, largely on the account of four Giants' batters hitting almost consecutive solo home runs in one inning. He pitched 4.2 innings, allowing seven earned runs and five total home runs.

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I was present at that game. My jaw was on the floor.

Turns out, based on a breakdown from Jomboy Media, he was tipping his pitches. When he went to throw his curveball, the top flap of his glove would flare up when he came to a set position on the mound. For the rest of his pitches, his glove would rest on his hand.

Therefore, Giants batters had an edge on him and dutifully made him pay.

Fast forward through three lackluster starts at the end of April to May, where he's started five games. He got through six innings with one earned run allowed over his first start in May against the Twins; although, he gave up five walks.


The White Sox dominated the bats during his next start against the Cincinnati Reds, putting up 11 runs in the second inning and 17 in the game. Kopech gave up eight hits and four earned runs through six innings.

Skip to the present day, as a gear shifted over his last three starts. He's pitched 19.2 innings over those starts, giving up four hits and two earned runs while striking out a whopping 24 batters.

Against the Kansas City Royals, he got through five perfect innings before Michael Massey broke up his perfect streak with a left-field single. Kopech pitched the most number of innings for his career (8) and didn't allow a single run while striking out 10 batters.

On Wednesday, during a series finale against the Cleveland Guardians, Kopech threw four perfect innings and got through seven frames. He allowed one hit and zero runs for the second straight game while striking out nine batters.

What's changed for Kopech?


Frankly, he's come a long way in a very short amount of time.

Almost two months ago, he gave up four home runs in a single frame. Now, over his last three starts, he's allowed four hits total.

"He was in just complete control of himself," Pedro Grifol said after his start on Wednesday. "He was focused. He was controlling the strike zone. I think he got through 14 changeups. That's a big, big deal for him. That's a big pitch. He's become now, a 3-4 pitch guy."

As Grifol mentioned towards the end, Kopech is starting to involve his changeup more in his arsenal. He's using it on 5.3 percent of pitches this season, according to Baseball Savant.


And while that may not seem like a lot, he's pitched 46 this season, which is well more changeups than he's ever thrown in a single season. Plus, he's only through nine starts in 2023.

As it stands now, his changeup is simply a supplemental pitch to his more dramatic pitches. His fastball has been lively. His control on that pitch is well more determined than at the beginning of the season. Not to mention, his slider has the best-run value this season than it's had since 2021.

Outside of the mechanical tweaks, hiding away his tells and perfecting the command of his pitches, Grifol points to the physical and mental work Kopech has put into this season as the reason he's seen so much success over his last few starts.

"He's tapping into his potential," Grifol said. "And it has nothing to do with the stuff. It has everything to do with the focus, the attention to detail, his mound presence. It has everything to do with that. Not just gameday, but the four days in between. You watch him work and he's just completely in the mind and another level of focus and detail."


In May, Kopech has the 16th-best ERA among starters (2.55 ERA). Opposing batters are hitting just .136 against him. And he holds a 0.93 WHIP, too. Alas, his first start of the season was a fluke.

Kopech's success is very convenient for the team right now, too. Mike Clevinger recently hit the 15-day injured list due to right wrist inflammation. On Tuesday, the Sox were forced to start Jimmy Lambert paired with Jesse Scholtens as a long-inning reliever.

Nevertheless, Kopech's starts have helped the White Sox to three straight series wins, all over teams in their division (Guardians, Royals). They'll face another one this weekend in the Detroit Tigers on the road, where they could realistically move to second place in the division.

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