I get things wrong all the time, so humility is one of my key assets. When my Miami Marlins coverage is missing critical information or context, I’ll put in the effort to rectify the initial mistake.
Over the course of the 2025 season, I watched all 20 of Eury Pérez‘s starts. While Fish On First followers Vik Torres and Mike Morhardt noticed that Pérez generally lifted his hands above his head when pitching from the windup (with the bases empty), that didn’t stick in my memory. Pulling up footage from the end of the year, the 22-year-old kept his hands close to his chest throughout his delivery, and I assumed that had always been the case.
As I pored over more footage from previous starts, I discovered my error. On the bright side, that research has equipped me with interesting analysis to share with all of you.
Pérez was dismantled by the New York Mets during a start at Citi Field on August 29, failing to get through the first inning. The road trip continued with a visit to the Washington Nationals, and that outing was just as discouraging when adjusting for the quality of competition (4.0 IP, 8 H, 7 ER, 1 BB, 2 K, 76 pitches/47 strikes). As the wheels fell off against the Nats, that’s when the talented right-hander began experimenting with lowering his hands. He adopted it as his full-time windup routine on September 10.
Here is a side-by-side of Pérez pitching from the windup in his games before and after the aforementioned road trip:
There’s a twist—Pérez’s mini-slump in NY and DC notwithstanding, he generally thrived from the windup in 2025. In 251 plate appearances with the bases empty, opponents slashed .160/.247/.293. He struck out 29.5% of batters compared to 23.1% with runners on base. If he had maintained most of that effectiveness when working from the stretch, he would’ve easily been Miami’s best starter.
That being said, this late-season change was a boon to Pérez’s overall production. During his final four starts, there were increases to his whiff rate, first-pitch strike rate and fastball velocity. He posted a 2.70 ERA in 20 innings pitched. A superhuman 42.3 K% contributed to his 1.09 FIP over that stretch, the seventh-best mark in MLB (min. 10 IP).
As you can see from Pérez’s most recent bullpen session, he is sticking with his September adjustment entering 2026.
Our own Kevin Barral spoke with Pérez last week about how offseason weight gain and refinement of his secondary pitches will also help him realize his full potential.