Over ten years ago, JoJo Romero was drafted by the Phillies in the fourth round (107th overall) of the 2016 MLB Draft. He went on to make his major-league debut during the pandemic season, and didn’t turn any heads. Tommy John surgery cut his season short in ‘21. Romero posted a pedestrian 12% K-BB%, and an acceptable 86 DRA- in his limited time with Philly. In August 2022, he was traded to the Cardinals for utility infielder Edmundo Sosa, and both teams have to feel fairly satisfied with the result. Romero saw a bit of a resurgence in St. Louis before POBO Chaim Bloom decided to sell high on the lefty and his expiring contract at the 2026 trade deadline, shipping him to the Brewers for a handful of prospects.

I’m captivated by Romero, not because his name is fun to say or because he shares a name with one of my favorite anime shows. His stats are a vexing web of contradictions. A pitcher whose ERA is lower than his FIP is expected to regress. Since 2024, his -0.92 ERA-minus-FIP ranks 12th among qualified relievers, but as the “since 2024” provision infers, his expected regression hasn’t manifested.

Let’s take a step back. Across his first two seasons, Romero posted an RA9 that was significantly higher than his DRA. For a ground-ball pitcher, having Alec Bohm manning the hot corner behind him (-1.8 DRP between ‘20-21) didn’t do him any favors, nor did his home stadium. Migrating from the hitter-friendly confines of Citizens Bank Park (102 park factor, fifth overall) to the ever-cavernous Busch Stadium (97, 26th) certainly helped him, too. Part of the gap in Philly is sample size. He threw just 21 ⅔ innings between 2020 and 2022, and a couple of bad outings in a short stretch will blow up a pitcher’s RA9.