Among the reasons for optimism in Toronto is that Aaron Sanchez is back. Sure, you never really know when any pitcher will stay good and healthy, but Sanchez was able to start just eight games in 2017, due to significant blister problems. So far this year, the problem hasn’t recurred. As far as the Blue Jays go, the problem isn’t upper-tier talent. The problem is keeping all that talent on the field. If Sanchez can throw another 30-odd times, that’ll answer at least one major question.

Now that Sanchez is two starts into 2018, we can say that there’s been good and bad. He’s still throwing hard, and he’s getting ground balls. That’s good. Less good are the early problems with control, although maybe Sanchez deserves a break for struggling against the Yankees. Plenty of pitchers are going to struggle against the Yankees. Sanchez just looked fine against the White Sox, and, even more important than that, we’re seeing an adjusted Aaron Sanchez. Sanchez has unveiled a new weapon of his, something he’s never been able to consistently possess. From the looks of things, 2018 Aaron Sanchez has a far better changeup. It’s also one of the hardest changeups in the game.

I’m going to throw some Brooks Baseball plots at you. Ready? Great! Here’s the major one.

That tells a story by itself. Through his first four years in the majors, Sanchez never used his changeup much. It was there, never completely going away, but Sanchez clearly didn’t trust it. Now, through two starts, Sanchez has thrown this pitch a quarter of the time. It’s taken a bite out of his sinkers, and it’s taken a bite out of his curveballs. Against the Yankees, Sanchez threw 19% changeups. Against the White Sox, he threw 32% changeups. This is now officially a major part of his arsenal.

What’s going on with the change? The velocity isn’t really new. Here’s a velocity plot, showing Sanchez’s sinker and changeup.

The changeup has added a little bit of zip, but it’s still hovering around 90 miles per hour. That’s fast, for a changeup. Moving on, the changeup still tails, just as the sinker does. This is showing horizontal movement.

The change and the sinker mirror one another. I don’t yet know what to make of the big shift for both pitches in 2018 — it might just be a calibration thing, or it might be a consequence of Sanchez lowering his arm angle. Any lowered arm angle will have an effect like this on horizontal break. Moving to the final plot, vertical movement is where we see a tweak. This, I believe, is what’s exciting.

A good, reliable changeup is all about separation. In terms of velocity, Sanchez doesn’t get so much separation. So he’s added another separator. Compared to the sinker, and certainly to the four-seamer, Sanchez’s 2018 changeup drops more than ever. It always had some sink, but now it has plenty of sink, separating itself from the sinker in two ways. I’m going to guess Sanchez made some sort of changeup grip adjustment. The bottom now falls out of the pitch, turning it into a legitimate weapon.

Sanchez has already generated five strikeouts with his changeup. Through 2017, he picked up a total of just 13 strikeouts with his changeup. Against the White Sox, Sanchez picked up ten changeup swinging strikes, easily besting his previous career-high of four. For perspective: In two games, opponents have swung at 22 Sanchez changeups, and they’ve missed 13 times, for a rate of 59%. Sanchez’s previous career rate was 24%. It’s early, I know, but Sanchez has effectively kept his changeup down, and it’s pairing better than ever with his heaters. If he didn’t already trust the pitch, he wouldn’t be throwing it so often to major-league hitters.

Before, Sanchez’s change dropped 1.8 inches more than his sinker, and 4.4 more inches than his four-seamer. Let me do something real quick. Three righties who’ve had amazing changeups with limited velocity separation are Zack Greinke, Felix Hernandez, and Carlos Carrasco. They’ve averaged a gap of 4.4 miles per hour compared to their sinkers, and 4.8 miles per hour compared to their four-seamers. Sanchez right now is at 4.6 and 4.6, respectively. And, those three have averaged a gap of 4.6 inches compared to their sinkers, and 7.2 inches compared to their four-seamers. Sanchez right now is at 4.2 and 6.8, respectively. Sanchez, in other words, is very close. He’s added another two or three inches of vertical separation, and even though I know that doesn’t sound like much, a baseball bat can’t be wider than 2.6 inches. The way Sanchez is throwing his changeup makes it far more likely he can get a swing and miss.

Check out this fun three-pitch sequence to Jose Abreu. Here’s a standard Aaron Sanchez fastball.

Sanchez followed with a changeup.

That one couldn’t get a swing. The next one could.

That is an absolutely perfect changeup. Run anyone out there and eventually everyone will luck into a perfect changeup, but Sanchez hasn’t just been feeling things out. He’s thrown the changeup a lot. He’s thrown it in meaningful games, and he’s thrown it to lefties and righties alike. He’s used it overwhelmingly often in two-strike counts. Sanchez is using the changeup as if he loves it. And based on how it looks, it’s an easy changeup to love. And for a guy like Sanchez, it could be a difference-maker.

Sanchez has been plenty good before. It’s not like he’s never come close to his ceiling. And before anyone figures that Sanchez is an ace now, he needs to throw consistent strikes. His control does definitely waver. But the strikes should be there in time, based on Sanchez’s last full season. And for any righty with a powerful sinker, the challenge can be working good sequences against lefties. That’s precisely where a solid changeup would come in handy, to say nothing of how Sanchez could use the pitch against righties, too. Sanchez has a breaking ball, and it’s been fine. It’s not going to go away. This changeup, though, has perhaps already surpassed it, and this changeup could be one of the more exciting developments of the year. It profiles like one of the best changeups in either league. Sanchez just needs to continue throwing it like he already has.