Freddy Peralta's Arsenal Isn't What It Used to Be, and His Fastball Explains Why

There's something unusual on Freddy Peralta's FanGraphs page. His Stuff+ sits at just 95, a mark below league average and one of the lowest among the Mets' primary starters. For a pitcher whose reputation was built on the quality of his arsenal, that number immediately stands out.

At first glance, it looks like the profile of a pitcher with an ordinary repertoire. The results, however, suggest something more complex—a contradiction that becomes easier to understand when examining Peralta's four-seam fastball.

For years, that pitch served as the foundation of everything he did on the mound. It wasn't the hardest fastball in baseball, but it consistently played above its velocity, generating swings and misses and helping establish Peralta as one of the National League's toughest pitchers to square up.

The numbers now point to a clear shift.

The trend is difficult to ignore. A pitch that once graded comfortably above average now falls below that threshold.

What's notable is that the rest of Peralta's arsenal has not experienced the same decline. His slider still carries a 102 Stuff+ grade. His curveball sits at 109, one of the strongest marks in his repertoire. Even his changeup remains largely in line with previous seasons.

Rather than reflecting a broad deterioration across his pitch mix, the drop in Stuff+ is concentrated almost entirely in the fastball.

Part of the explanation, as it is for any 30-year-old pitcher, is velocity. After averaging 94.8 mph on his four-seamer in 2025, Peralta is averaging 93.8 mph this season. A one-mile-per-hour drop may not sound dramatic, but for pitchers who depend heavily on fastball effectiveness, even modest losses can alter how a pitch plays against major league hitters.

The swing-and-miss metrics tell a similar story. Peralta posted a 39.7% whiff rate in 2020. In 2026, that figure has fallen to 28.1%. His whiff rate ranking has also dropped, from the 83rd percentile to the 72nd percentile in just one season.

Hitters are making more contact, and pitch-quality models are reflecting that reality. The more important question is what those changes mean. If the fastball explains much of the decline in Stuff+, why is Peralta still able to perform (on most night, at least) like a frontline starter?

The answer becomes clearer when looking beyond raw pitch quality.

These numbers describe a pitcher whose success depends less on pure stuff than it once did and more on how effectively he deploys his arsenal. While his Stuff+ now sits below league average, his execution remains strong. That distinction helps explain why his overall performance has remained stable despite the decline in pitch quality.

Many pitchers experience a gradual loss of stuff. The ones who remain effective are typically those who find other ways to compensate, and Peralta appears to fit that description. Despite the drop in Stuff+, his fastball continues to produce positive results. Opponents are hitting just .227 against the pitch and have generated only a .294 wOBA. It no longer earns elite grades from pitch-quality models, but it remains an effective weapon within his overall mix.

Earlier versions of Peralta could overwhelm hitters with the raw quality of his pitches. The current version relies far more on execution, location, sequencing, and an ability to maximize every offering in his repertoire. As a result, the margin for error is smaller than it once was. The performance, however, has remained remarkably consistent, which is why a 95 Stuff+ requires additional context.

Yes, hitters are making more contact. Swings and misses are less frequent. The models see a less dominant arsenal than they did a few years ago. Yet the overall results remain largely intact.

That is the real story behind Peralta's evolution on the mound. It's the story of a pitcher preserving his value through execution, command, and a deeper understanding of how to leverage the stuff he still has.