Is Freddy Peralta's Increased Slider Usage Here To Stay?

[Andres Chavez]

Image courtesy of © Brad Penner-Imagn Images

Freddy Peralta’s first turn in a New York Mets uniform wasn’t exactly a masterpiece if you only glance at the box score. Giving up four runs over five innings, including a pair of homers to Brandon Lowe, usually feels like a rocky start for a new ace. But box scores are a bit like looking at a finished painting from across the room: you see the colors, but you miss the brushwork. If you step a little closer, there was plenty to suggest that Peralta’s outing was far more calculated and promising than it appeared.

The most striking part of his afternoon wasn’t the hits he surrendered, but the way he attacked. Peralta didn't walk a single batter while striking out seven, showing a level of aggression that keeps a defense on its toes. He leaned on his four-seam fastball about 49 percent of the time. That’s close to last year’s 53.5 percent mark. The real story, however, lived in his secondary pitches.

A New Look for a New Team

The slider suddenly became the guest of honor in Peralta’s repertoire. He threw it nearly 29 percent of the time against the Pirates, a massive jump from the 10.2 percent usage we saw in 2025. Last year, the slider was essentially the forgotten tool in his shed, buried behind his changeup and curveball. On Thursday, it was his primary weapon of choice.

This shift wasn't a random roll of the dice, either. Statistically, Peralta’s slider is a nightmare for hitters, boasting a .161 xwOBA and a 52.8 percent whiff rate last year, both elite marks. Doubling down on your best pitch is rarely a bad strategy. Furthermore, the Pirates ranked 29th out of 30 teams in 2025 with -53.7 slider runs above average, or, in this case, well below average. Only the Colorado Rockies were worse against that specific pitch type.

It was a classic case of a pitcher playing to his strengths while exploiting a known weakness in the opposition.

We have established that Peralta did, in fact, favor his slider over his other secondaries in the opener. Was it good, though? Well, that depends on what you're looking for.

The Double-Edged Sword

When the slider worked, it was like a disappearing act. Peralta generated a 64 percent whiff rate with the pitch on Thursday, bamboozling lefties and righties alike. It was a swing-and-miss machine that looked nearly unhittable at times. However, baseball is a game of inches, and when the slider missed its spot, the Pirates made him pay:

Despite the whiffs, the actual results on balls put in play were loud. One of Lowe's home runs and a double came off the slider, leading to a bloated 1.037 wOBA. The underlying numbers, specifically the xwOBA of .235, suggest that Peralta actually pitched much better than the results indicated. The issue wasn't the pitch itself, but the location. He missed his spot high a few too many times, a death sentence for a slider without huge sweeping tendencies.

Refinement on the Edges

Television broadcasts might have mislabeled the offering of that Lowe home run as a curveball, but the data, in this case Statcast, says it was the slider. The movement was there, the velocity was right, and the intent was clear. If Peralta can move that pitch from the middle of the plate to the edges, it transforms from a liability into a lethal weapon.

As he settles into the rhythm of the season and grows more comfortable in New York, the command should follow the stuff. This debut wasn't a red flag; it was a blueprint for how dominant he can be once he stops finding the fat part of the bat with one of his best breaking pitches.

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