The Most Unhittable Pitch Is in the Astros Bullpen

There are a lot of pitchers, right? There are a lot of pitchers, and, therefore, there are a lot of relievers. Some of them have long been great. Some of them have more recently been great. Others have just kind of hung around. Many of them are relatively anonymous. Ryan Pressly has been one of the more anonymous ones. He’s been in the majors since 2013, but we’ve almost never written about him here. Rian Watt did change that a month ago. He wrote a whole article about Pressly, who was dealt from the Twins to the Astros near the end of July.

Watt focused a lot on Pressly’s curveball. He’s been leaning heavily on that pitch, especially since arriving in Houston. Pressly, who’s a righty, throws a four-seam fastball, a curveball, and a slider. It’s an interesting mix for a reliever to have, and it’s further interesting how easily Pressly goes from one pitch to another. He’s not a one-pitch specialist. He’s not a two-pitch specialist. He mixes. He likes everything he throws.

He throws that slider more than a quarter of the time. He’s had a slider for a while. Most pitchers have. But there’s something different and special about Pressly’s slider today. Absolutely, the curveball is important. The fastball’s important, too. It all works together. But Pressly’s slider in 2018 has been baseball’s single most unhittable pitch. That’s measured by how infrequently it’s been hit.

Since the season began, Pressly has thrown right around 300 sliders. So I looked through every individual pitch-type thrown at least 250 times. That gave me a sample of almost a thousand pitches to choose from. Here are the top ten pitches in baseball, by whiff rate. Not contact rate — this is the rate of pitches that got a swing and miss.

Here’s how to think about this: This season, when Pressly threw a slider, it resulted in a swing and miss almost a third of the time. For every three sliders, he got one whiff. That puts his slider in first place, and it’s in first place by multiple percentage points. It’s not easy to get that kind of spread. Look at the difference between, say, Smith’s slider and Diaz’s slider. All of these pitches have been effective, but none has missed bats like Pressly’s slider. And I’ll point out, for fun, when contact was made against the slider, almost everything was put on the ground. Just a real great pitch, that one.

Again, Pressly has thrown a slider for a while. It’s a hard slider, too, hovering around 90 miles per hour. The very idea of a breaking ball at 90 is almost unfair. Pressly’s slider this season got 33% whiffs. His slider last season got…15% whiffs. The season before that, 17% whiffs. What’s changed, as far as this pitch is concerned? It’s easy to point to one thing — Pressly has used the pitch differently. The heat maps give it away. Here are Pressly’s 2017 and 2018 sliders, viewed from the catcher’s perspective.

It might just be a matter of feel, but what you see on the right is more of what you want from a slider. The pitch has been thrown with consistency down and to the glove side. For a right-handed hitter, that’s a lethal slider low and away. For a left-handed hitter, that’s a back-foot slider at 90 ticks. Let’s hold there for a second. Here are Pressly’s whiff rates by pitch type, against lefties and lefties alone (via Brooks Baseball):

You see the slider taking off. Lefties have had no answer for the pitch. That’s pretty uncommon for a right-handed slider, but you can observe Pressly’s progression. In 2016, facing lefties, Pressly’s K-BB% ranked in the 35th percentile among right-handed pitchers. In 2017, it ranked in the 55th percentile. And in 2018, it ranked in the 97th percentile. Pressly, in the past, was more of a run-of-the-mill reliever, a righty who could have success against most righties. This season, he’s taken the next step. He’s become a good pitcher against everyone, and he’s turned his slider into a featured pitch. The curveball might get more of the attention, but that slider has been a knockout.

There’s another usage change here. Pressly has aimed his sliders differently, but he’s also timed his sliders differently. In the past, when Pressly found himself in a two-strike count, he went to his slider about once for every ten pitches. This season, when Pressly has found himself in a two-strike count, he’s gone to his slider about once for every three pitches. And so the results are laughable: Pressly racked up 41 strikeouts on his slider. Over the five previous years *combined,* that total was 16. Pressly didn’t make dramatic changes to his slider, but by getting more comfortable with it, and by using it in a different manner, the pitch has turned into a preeminent weapon.

It’s about that time where I show you what the slider looks like. I’ve captured three videos from Pressly’s first ALDS appearance against the Indians. Here’s a whiff against Jose Ramirez:

Here’s a whiff against Yonder Alonso:

And here’s a called strike against Edwin Encarnacion:

That last one is important. The slider is a swing-and-miss pitch, but not exclusively. You can tell that Pressly controls his slider well. The sign of a great breaking pitch is one that can be thrown for a strike when you need it. That’s a slider Encarnacion would have to keep in the back of his mind when he’d think that Pressly was about to try to make him expand.

One real good pitch would be a hell of a starting point. For Pressly, it all comes together when you recognize he has a strong full repertoire. Here are his three pitches, expressed in terms of percentile ranks for their pitch-type-specific whiff rates.

Pressly has thrown the best swing-and-miss slider. His slider has been the best swing-and-miss anything. But he’s also thrown a swing-and-miss fastball and a swing-and-miss curveball. He’s done well to mix everything, never leaning too heavily on any one pitch in any one count. Pressly, in short, has three quality pitches, and he doesn’t throw them in easily observable patterns. So if I can show you one more plot, this is a pretty simple one, featuring everyone who threw at least 50 innings this year. On one axis, you’ve got strike rate. On the other axis, you’ve got contact rate. I’ve highlighted Pressly in yellow.

A strike-thrower who doesn’t get hit. We’re looking at 336 different pitchers. Pressly ranks 28th by strike rate, and third by contact rate. Those two dots right by him correspond to Josh Hader and Edwin Diaz. Two of the most dominant relievers in baseball. Ryan Pressly would therefore also stand to be one of the most dominant relievers in baseball. He’s just not widely recognized. But there’s little he’s not able to do. He’s able to retire any hitter you put up against him.

The Astros didn’t make major headlines when they swung the Pressly trade, and even now, with Pressly coming off an overwhelming second half, he doesn’t have close to the name recognition of many of his teammates. For the most part, even after a dominant season, Pressly remains one of those anonymous relievers. He might not be so anonymous by the end of the month. October is when so many stories get written. October is when you get the best chance to star in the spotlight. For as long as the Astros are around, Pressly’s going to be handed some critical innings. He has the full trust of his coaching staff, and it’s clear that he damn sure deserves it.