Puk thrives with MLB's trendiest pitch

This story was excerpted from Christina De Nicola’s Marlins Beat newsletter. To read the full newsletter, click here. And subscribe to get it regularly in your inbox.

Baseball's trendiest pitch this season is the sweeper.

Entering Thursday, 90 pitchers have thrown at least one sweeper in 2023, according to Baseball Savant, and Marlins closer A.J. Puk is among them. He has heavily relied on it, tallying the sixth-highest sweeper usage (50.4%, min. 100 pitches thrown) among all Major Leaguers.

During his first full season in 2022, Puk utilized his four-seamer (46.4%), slider (38.1%), sinker (15.4%) and changeup (0.2%). But Oakland teammate Sam Moll "spun the crap" out of a sweeper, which led Puk to consider the pitch. After talking to Moll quite a bit about it, Puk decided to add it to his repertoire. When the A's told Puk they were going to stretch him out as a starter ahead of Spring Training in 2023, he found it to be the perfect opportunity to change his arsenal to that of a sweeper, cutter and split finger.

"I just wanted something with a little more movement and a little slower, too," Puk said. "I think it's better, because [it used to be that] everything's hard, hard, hard. Now, though, I've got something slower. They've got to sit back on [it]. And then with my fastball, I think it plays well with each other."

Despite serving in relief rather than a starting role in Miami, Puk has kept the sweeper and splitter. He hasn't thrown the cutter, because he fears spinning one down the middle of the plate at 90 mph in a high-leverage situation and negatively impacting the ballgame. Once Puk gets more comfortable with the cutter, however, he'd like for it to be a regular offering.

Puk's sweeper, meanwhile, has become his most-used pitch. Not only does it have a different grip but it also has a different feel out of his hand than his slider. There's a little more gyro spin to it, with more horizontal break. The idea is for the pitch to keep going outside and hopefully get around the barrel to lefties while getting in on or blowing up the barrel of righties.

The data supports this so far:

• Spin rate: 2,316 rpm for sweeper (2023); 2,232 rpm for slider ('22)
• Horizontal movement: 8.5 inches for sweeper; 3.3 inches for slider

"That type of movement and spin -- it does sweep and it's got a little turndown," pitching coach Mel Stottlemyre Jr. said. "It's not like that [Steven Okert] upward sweep, but it keeps biting at the end. The angle's a little different. And for me, on top of that sweep down at the bottom, what complements that is his fastball at the top. It can't be easy. I'm not a hitter. It turns hard, and I think there's sweep and then pitches that get to spots. And then I think there's the aggressive turn and bite of a breaking ball, and he definitely has that. It's not lazy.

"He's got a low slot, and it keeps coming to the hitters, from what I've talked to him. It just doesn't stop. It's got that kind of finish and bite to it."

In 14 at-bats that have ended on a sweeper, Puk has given up just one hit and struck out two batters. It already has a -3 run value. His four-seamer, which averages 95.6 mph, continues to be his putaway pitch (35.3%) and is thrown 45.3% of the time overall.

"It's a new pitch, and [I'm] still getting comfortable with it," Puk said of the sweeper. "I'm happy [with] where it's at. Last year, I was a little more aggressive with my heater, but here I can be like 50/50."