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Dauri Moreta¡¯s?slider is among the best in baseball. It¡¯s at the top of the leaderboards in several categories, and with that pitch in his bag, Moreta is enjoying a career year. There is, however, a problem with the pitch.

There¡¯s no consensus as to whether it¡¯s?actually?a slider.?

¡°You can call it whatever you want, but in my mind, it¡¯s not a slider,¡± said?Jason Delay.

¡°It¡¯s still a slider. It still acts like a slider the way it spins [and] the action on it. Sometimes, it does some really, really weird things,¡± said?Austin Hedges.

¡°Well ¡­ it¡¯s a slider,¡± said pitching coach?Oscar Marin. ¡°But it¡¯s more of a screwball for me.¡±

Moreta considers his pitch a slider. Baseball Savant classifies it as a slider. The pitch, however, does not act like a?slider -- at?least, all the time.

The first?version -- the?¡°normal¡±?version -- doesn¡¯t?have a ton of horizontal movement, but looks like a run-of-the-mill slider. Here¡¯s an example:

The second version, by contrast, looks nothing like a slider and is defined by its arm-side run. Here¡¯s an example:

So, what¡¯s going on here? These two same-but-different pitches fall under the umbrella of ¡°slider¡± and the metrics are all out of whack.?

Moreta¡¯s average slider?averages -12.0 inches of horizontal movement compared to sliders with similar velocities and release points. That¡¯s dead last in the league.

When Delay, Hedges and Marin were asked about the slider, there was one other pitch that all three separately mentioned.?

¡°The slider does have some slider traits at times, but when it¡¯s really, really good, we see the tendency of that slider working like a screwball and actually going the opposite direction,¡± Marin said.?

¡°It¡¯s anywhere between a slider and a screwball,¡± Hedges said. ¡°It¡¯s a legitimate screwball when he throws it a certain way; you definitely can¡¯t call it a slider sometimes.¡±

Recalled Delay, ¡°I remember the first time I caught it in Spring Training, I was like, ¡®Is that a screwball? What¡¯s going on there?¡¯¡±

Delay and Hedges have caught their fair share of pitchers over the years, but neither could think of a single one who had a pitch that moved like Moreta¡¯s slider. Marin, however, recalled Drew Smyly, whose curveball also moved in the opposite direction, making Moreta¡¯s slider less of a surprise.?

¡°But that was the curveball,¡± Marin said. ¡°For someone to have a slider like that, it¡¯s pretty unique.¡±

Moreta learned his slider from right-hander?Matt Pidich, a teammate of Moreta¡¯s with Triple-A Louisville last season. Moreta recalled that he lost his slider at one point, but he rediscovered the pitch thanks to Pidich, practicing with Pidich just about every day.

¡°I honestly don¡¯t know how he does it,¡± Hedges said. ¡°It starts its way moving left, then it comes back right. It¡¯s really wild.¡±

If Hedges wants an answer as to why Moreta¡¯s slider moves how it moves, he won¡¯t find any answers by asking Moreta himself.?

¡°I don¡¯t know why it goes the opposite way,¡± Moreta said. ¡°I don¡¯t try to do that. It¡¯s natural. I just throw it like a normal slider, and it does that.¡±

Delay and Hedges know to be prepared for a ¡°slider¡± that might move in either direction. Delay, who also likened the pitch to a changeup and splitter due to its arm-side run, described the necessity to swallow his pride when catching Moreta¡¯s slider. While catchers naturally want to frame, Delay and Hedges¡¯s focus with Moreta¡¯s slider is just catching the ball. The slider provides a unique challenge, but Delay knows that if the pitch is hard to catch, it¡¯s also hard to hit.?

¡°It¡¯s probably the most challenging pitch I¡¯ve had to catch, certainly this year and maybe in my career because you don¡¯t exactly what it¡¯s going to do,¡± Delay said.?

¡°I¡¯m not really anticipating anything about what it¡¯s going to do, and that¡¯s one of the beauties of being able to call it as much as we do,¡± Hedges said. ¡°Even if a hitter¡¯s looking for it, it¡¯s not going to have consistent movement; it¡¯s going to do something different almost every time.¡±

Given how the pitch grades out, Delay and Hedges find themselves catching that pitch often whenever Moreta takes the hill.

With a Run Value of -6, Moreta¡¯s slider ranks as one of the best in baseball. Across 45 plate appearances, opponents have a .075 batting average, .100 slugging and .166 weighted on-base average against the pitch. Moreta is in the midst of a phenomenal season -- 2.01 ERA, 3.11?FIP, 33 strikeouts in 22 1/3 innings -- and the slider is a big reason why.

Considering the results, it¡¯s not shocking that Moreta is leaning into the pitch more than ever. In 2022, Moreta¡¯s slider accounted for 24 percent of his pitches. So far this season, by contrast, Moreta¡¯s slider is accounting for 55.8 percent of his pitches. The Pirates are?throwing more breaking balls?than any team in the pitch tracking era (since 2008), and Moreta¡¯s sudden spikes is a significant reason as to why.?

Moreta is throwing the pitch more, in general, but he¡¯s also throwing it more to lefties.

In March and April, Moreta¡¯s primary way to attack left-handed hitters was with his changeup; through April, Moreta¡¯s changeup comprised 45.9 percent of the pitches he threw to lefties while his slider lagged behind at 21.6 percent.?

In May, by contrast, Moreta¡¯s slider is accounting for 48.3 percent of his pitches to lefties while his changeup is accounting for 31.0 percent. So far, Moreta hasn¡¯t allowed a single hit to a left-handed batter with his slider.

Moreta recalled a teammate who asked for the true name of his pitch and joked that Moreta¡¯s slider wasn¡¯t really a slider. Moreta will keep calling it a slider for now, but a rebrand isn¡¯t out of the question. Regardless of denomination, Moreta won¡¯t stop throwing the pitch anytime soon.

¡°This is an outlier pitch, and it¡¯s an outlier pitch that has really good results when located in a certain spot,¡± Marin said. ¡°His is completely different than anyone we have. We leaned on that pretty heavily once we saw that because we felt like, whether it¡¯s a legit slider or now, it¡¯s getting the results we want.¡±