North Shore Tavern Mound Visit: Perez's cutter the key to a potential comeback

There were 84 pitchers who had at least 50 plate appearances end with a cutter in 2022, and Pérez had the 10th-lowest slugging percentage. In 2023, 106 pitchers hit that mile marker, and Pérez's slugging percentage allowed was the fifth-worst. Hitters went from a .228 batting average against it in 2022 to a .342 average in 2023. Going by Baseball Savant's run value, his cutter was worth 13 runs more than league average in 2022 and 13 runs less than average in 2023. 

And the deeper you dive in, the uglier it gets.

Not only did hitters make hard contact (the average exit velocity went from 86.8 mph to 88.6mph), but hitters elevated it more. When Pérez is at his best, he's getting weak contact and ground balls. The cutter didn't yield nearly enough of either. Compare the launch angles of the hard contact he allowed in 2022 to 2023.

Here is 2022:

And here is 2023:

Every pitcher gives up some hard-hit contact, but in his All-Star campaign, it was mostly low line drives. Sure, those balls were still tagged and resulted in plenty of hits, but most of them were singles and just two were home runs. In 2023, not only did he allow more hard contact, but hitters were able to put it in the air, resulting in 10 home runs.

He also got fewer whiffs with the cutter. He relies on the sinker as his primary fastball, so he doesn't get a ton of strikeouts, but his strikeout rate dropped from 20.6% in 2022 to 15.3% in 2023. It's easy to see where those missing strikeouts were. His whiff rate with the cutter dropped from 17% to 11.7%, and his put away percentage (or the rate of two-strike pitches that result in a strikeout) was nearly halved, going from 27.5% to 14.3%. Pérez isn't going to strikeout a ton of hitters, but there's a big different between 7.8 K/9 and 5.9 K/9.

The cutter didn't have a significant change in spin, velocity or movement last year, so there's reason to believe he can get it closer to that 2022 form with some tweaks. It would also probably help if his sinker is sharper. Pérez's cutter is a vertical movement-driven pitch, which the sinker has more horizontal movement. They can tunnel off each other, and when he consistently lands the sinker on his hand side, like he did in 2022, it opens up those tunneling opportunities.

The sinker's results last year were pretty similar to what they were in 2022, but he didn't have the same command:

The sinker was all over the zone, especially in the middle. He got away with a lot of those errant pitches, but a misexecuted pitch can impact the entire sequence. If he isn't getting whiffs with the cutter, he doesn't have a strikeout pitch. If he isn't putting the sinker where he needs to, he's going to have less strikeout opportunities.

There's a good chance that Pérez's 2022 season winds up being his career year and he doesn't quite reach those highs again, but he can be more than just an inning eater. The Pirates needed another pitcher to go along with Mitch Keller and give a reliable five or six innings every time he touches the ball. He can do that, and they can be quality innings, too.

What remains to be seen is if the Pirates continue to add to the rotation.