Blake Snell Isn’t Fair Anymore

Blake Snell has turned into one of the very best pitchers in baseball, and in order to understand how and why, we can start by just looking at the most recent batter he faced. A couple days ago, in the bottom of the seventh, Snell struck out Rowdy Tellez. The first pitch was a slider for a ball, at 88 miles per hour. The second pitch was another slider for a ball, at 89. The third pitch was a slider for a foul, at 87. Then came a fastball for a ball, at 96. Then a curveball for a whiff, at 82. Then a curveball for a foul, at 81. Finally, a fastball for a called strike, at 98. Tellez was gone, and Snell was replaced by Chaz Roe, having thrown exactly 100 pitches.

It’s not that Snell is only just beginning to emerge. His turnaround began in the middle of last year, and he hasn’t looked back. It’s last season that now looks more like a breakout. This season, however, Snell is a contender for the AL Cy Young award, even despite a DL stint that threatened to derail his progress. And while Snell was strong in the first half, before his bout of shoulder fatigue, he’s come back nearly unhittable. Between halves, he’s chopped more than a run off his ERA. He’s chopped a run and a half off his FIP, and he’s done basically the same with his xFIP. He’s added ten points to his strikeout rate while trimming his walks. Blake Snell is like a dominant closer who throws for six innings.

In one way, it’s not hard to see where Snell has improved. Yet his most recent changes are far more subtle. And they might well be the last changes he has to make for a long time. All that’s left for Blake Snell is to stay healthy.

Snell’s stuff tells a story of its own. He debuted in the majors in 2016, and, from the beginning, he’s offered a fastball, a slider, a curveball, and a changeup. Here’s how quickly those pitches have been thrown:

It’s not difficult to spot the common trend. Everything Snell throws, he’s throwing harder than he used to. We’re accustomed to focusing on average fastball velocity, and, since 2016, Snell has added a tick and a half. But it’s also worth looking at the rest of the repertoire. Snell has added two ticks to his changeup. And he’s added five ticks to both his slider and his curveball. Five miles per hour, for Snell’s breaking pitches. There’s not an absolute relationship between velocity and effectiveness, but given the entire rest of the picture, I think we can say pretty conclusively that, for one reason or another, Snell is throwing his best-ever pitches. His mechanics are in sync, and one can assume he’s worked to increase his arm strength.

As Snell’s stuff has gotten better, he’s gotten harder to hit. Proper results have followed. Snell, again, started showing more consistent flashes last year down the stretch. Nevertheless, there’s the matter of Snell’s particularly dominant second half in progress. Here’s his big-league career, expressed in terms of whiff rate:

So what’s happening now, that’s allowed Snell to become so unhittable? This is where we get to go under the hood. A big part of pitching is having good stuff. That much is obvious. But another big part of pitching is making sure hitters can’t guess what you’re going to throw. Aroldis Chapman’s fastball wouldn’t be Aroldis Chapman’s fastball if he announced it every time before he threw it. No pitcher ever does that, but emerging patterns can be predictable. And so, before we move further, there’s something to understand about Snell: Every pitch he throws is terrific. Not literally every pitch, but every pitch type. He throws those four different kinds of pitches, and here are their league-wide percentile ranks in run value per 200 innings:

I know the run-value numbers can be kind of noisy, but the real takeaway ought to be that Snell throws four different quality pitches. Fastball, 79th percentile. Slider, 80th percentile. Curveball, 97th percentile. Changeup, 90th percentile. That’s a sign of a pitcher who’s essentially complete. Good hard pitch, good offspeed pitch, good breaking pitches. So now think of how pitchers traditionally use fastballs. You tend to see more fastballs when a pitcher is behind in the count, and fewer fastballs when a pitcher is ahead. That’s all elementary stuff. Here’s how Snell’s fastball rates break down by count, splitting 2018 into halves:

This, I think, is the final key. This, I think, can explain why second-half Snell has been so much better than the already effective first-half Snell. When Snell has found himself behind in the count, he’s dramatically reduced his rate of fastballs thrown. When ahead in the count, he’s increased his rate of fastballs thrown. And then, when even in the count, Snell has reduced his rate of fastballs thrown. The end result is something that looks more like a balance; the end result is a guy pitching like he knows he has four good pitches. Recall the Tellez sequence from the beginning of this article. First-pitch slider. A 1-and-0 slider. A 2-and-0 slider. A 3-and-1 curveball. Snell wasn’t entirely predictable before, but now it’s all even more of a guessing game. Which makes it easier to get the most out of your pitches.

Here are the pitchers with the biggest reductions in fastball rate when behind in the count:

It’s Snell in the lead. Here are the pitchers with the biggest increases in fastball rate when ahead in the count:

Snell shows up again. And here are the pitchers with the biggest reductions in fastball rate when even in the count:

There should be no disputing that Snell has been using his pitches differently. The changes are far too big to be an accident, and while it might be because of Snell, or because of the catchers, or because of the coaches, or because of the front office, Snell has gotten to benefit, and opponents have had to suffer. In traditional fastball counts, Snell has taken to pitching backwards. In traditional non-fastball counts, Snell’s been throwing more fastballs, showing hitters something higher in the zone. And then, in even counts, Snell hasn’t favored his fastball so much, because there’s no reason to. You don’t have to favor your fastball when all four of your pitches are good. Hitters *want* most pitchers to favor their fastballs. Snell is finally pitching like he knows it.

This isn’t a guy I’d describe as having pinpoint command. Even now, from time to time, Snell will find himself in trouble with walks. But his individual pitches are the best they’ve ever been, and his usage of those pitches is also the best it’s ever been. At any given time, Snell has four dangerous weapons stuffed in his back pocket, and you never really know which one he wants to use. Pitchers are frustrating, because peaks can be fleeting; injuries are always present as a looming concern. But the healthy Blake Snell is clearly one of the very best pitchers around. There’s so little room left for him to improve.