Eury Pérez, Starting Strong

If you’re like me, this year’s bumper crop of pitching prospect debuts has overwhelmed you. I write about baseball for a living, and it still gets to be too much for me sometimes. Mason Miller, Bryce Miller, Taj Bradley, Bobby Miller, Grayson Rodriguez, Andrew Abbott, Michael Grove… you could almost make an entire starting rotation just out of Millers. Some of these debuts have been spectacular. Some have been lackluster. Some are works in progress. It’s hard to tell what’s real and what’s hype.

That leads me to Eury Pérez, our top pitching prospect and perhaps the most anticipated debut of the year. It’s easy to equate all debuts, or at least to think of them as quite similar until a pitcher does something to set himself apart. Don’t fall for that trap, though. I’m here to tell you: Pérez is amazing, and it’s time to start paying attention to him if you’ve been missing out.

One thing is almost universally true about the heralded pitching debuts this year: these guys have stuff coming out their ears. I don’t mean that in an ‘ew gross earwax’ way, either: they’re tooled up like you wouldn’t believe. I think that’s just the way the world works now. Teams are better than ever before at applying objective measurements to individual pitches. In the past, a guy toiling in Hi-A with so-so numbers wasn’t going to the bigs regardless of how much vertical break he imparted. Now, if you’re throwing a fastball that looks at home in the majors, your team knows right away.

On this front, Pérez absolutely delivers. I’m not saying anything particularly controversial here, I know, but it’s worth reiterating. Before the season, Eric Longenhagen put eye-popping grades on Pérez’s arsenal: future values of 70, 60, 50, and 60 for his fastball, slider, curveball, and changeup, respectively. Early on, those grades look prescient; PitchingBot has those pitches at 69, 55, 54, and 55. Stuff+ isn’t as much of a believer; it thinks that only the fastball is above average, but it likes the fastball so much that it thinks Pérez has great overall stuff anyway.

Again, this shouldn’t surprise you. Good pitching prospects these days seem to have good stuff always, and Pérez is the best pitching prospect. Of course he’s throwing gas. He’s 6-foot-8 and tops out around 100 mph. The nastiness is clear to see. This mostly won’t be one of those GIF-laden pitching articles, but c’mon, let’s get at least one GIF in anyway:

Goodness gracious, that’s electric. But again, you kind of knew this. He wasn’t going to be lobbing cupcakes in there. Everything builds off that fastball, which he throws roughly 45% of the time. Hitters have no choice but to respect the pitch; he fills the zone with it and will throw it both to get back into counts and with two strikes.

Amusingly enough, Pérez’s fastball doesn’t miss many bats. It has a ton of movement. It has a ton of velocity. It comes from a strange angle. Major league hitters are just really good at getting their bat to fastballs these days, and they’re coming into at-bats against Pérez with one thing on their mind: see fastball, hit fastball.

There’s a clear weakness to this strategy: Pérez’s other pitches carve hitters alive. His slider doesn’t have a ton of break; it largely has gyroscopic spin and uses its differential movement from the fastball to miss bats rather than sweeping like the new hot trend. That might not sound like much, but looking like a fastball and then not being one is clearly working for Pérez. That slider is generating swinging strikes more than 20% of the time, generally making batters look foolish. It’s not so much its inherent excellence — just, good luck getting a bat on something that’s 20 inches lower than where you’re looking.

His curveball? You guessed it: no one can hit that dang thing. He’s thrown only 100 or so, but that curveball sports the highest swinging-strike rate in the game. Stuff models don’t think it’s anything special. Pérez struggles to spot it in the strike zone; he has the third-lowest zone rate among all curveballs, right around 30%. It doesn’t matter; hitters are swinging through that pitch like it briefly stops existing halfway to the plate.

You get the idea by now: his changeup is also garnering swings and misses left and right. This is just the lay of the land right now; Pérez’s fastball is so electric, and he’s so adept at throwing it for strikes, that batters are fighting a losing battle to keep from being overwhelmed by that single pitch — and losing everywhere else as a result.

Ordinarily, this is the part where I’d tell you to pump the brakes just a tad in your hype. I don’t want to, though. The warning signs that so many other pitchers sometimes flash haven’t really shown up in Pérez’s case.

The first place I look when it comes to stuff-monster rookies is command. “Have fastball, fastball will travel” is a fairly common skill set among phenoms, but if you can’t buckle down and throw in the strike zone when hitters display patience, you’re going to have walk issues no matter what else you throw. Pérez doesn’t have this shortcoming. When he’s behind in the count, he actually attacks the zone more than league average. There’s a reason Eric stuck a 70 on his future command; he’s so athletic that repeating his delivery seems to be second nature.

Another potential worry: one-trick ponies, particularly of the fastball variety. Bryce Miller is having a nice season, but I’m lukewarm on his long-term potential because he doesn’t have anything to pair it with. He throws some combination of slider, cutter, and curveball, but he doesn’t miss bats with any of them. His strikeout rate is headed south, and it’s no wonder: his only bat-missing pitch is a fastball, which just won’t play in the long run. Pérez doesn’t fall afoul of this either; as we’ve already covered, he’s stacking whiffs hand over fist with his secondary pitches.

What about stamina? I suppose this one is still somewhat in question. Pérez has been throwing between 80–90 pitches in most starts as the Marlins keep an eye on his workload. He doesn’t appear to be tiring at the end of starts — his average fastball velocity in the sixth inning is basically the same as his overall average — but it’s at least an unknown. Even on this front, though, Pérez looks great to me, going six innings in each of his past three starts, and it seems like the team is starting to give him a bit longer of a leash, which means more longer starts ahead.

These three warning signs are process-based rather than results-based, which is how I think about pitching. Statistics stabilize very slowly compared to how quickly fortunes change; by the time a pitcher’s ERA or even their FIP can tell you if they’re good, their underlying skill level might have changed. That goes double for rookies; there’s just no track record to lean on, which makes drawing conclusions extremely difficult.

But, uh, Pérez’s results-based statistics are also spectacular, so you can look at either and come away impressed. He has a freaking 1.34 ERA through nine starts. He’s striking out nearly 30% of opposing batters and walking only 8.1%. His 3.03 FIP is seventh among qualifying starters beginning on the day he was called up. His 1.2 WAR ranks ninth over that same span. It’s not just the raw stuff; his results scream top of the rotation mainstay too.

How rare is Pérez’s incandescent start? Depending on how you want to look at it, somewhere between awe-inspiring and extremely awe-inspiring. Since the start of the Wild Card era in 1995, no pitcher has posted a lower ERA in their first nine starts. Only 10 pitchers have recorded a better strikeout rate over their first nine starts (minimum 45 innings), and it’s a tremendously impressive list:

Rookie legend Stephen Strasburg? Hideo Nomo at the peak of his powers? Mark Prior and Kerry Wood? This is rarefied air. Pitchers this good don’t come around every day, or even every year. Combine the early dominance with the pedigree he already had coming in, and I’m very excited to see what Pérez has planned for us next.

So, should you be excited when a stuff monster prospect debuts? For sure, if only because it’s fun to watch. I don’t have a strong opinion about which of the rest of the current crop of arms will turn out the best. But more importantly, that “which of these innumerable prospects are best” uncertainty doesn’t apply to Pérez. He’s not just another debut. He’s an entirely different proposition: one of the best debuts we’ve seen in a long time. I’m not sure what else to say.