It’s probably no secret that, when the Blue Jays decided to try Aaron Sanchez as a starter, we were skeptics. It was nothing against Sanchez personally; from my perspective, at least, it was really quite simple. As a starter in the past, Sanchez never threw enough strikes. Big velocity and everything, but, not enough strikes. Most of the time, pitchers who struggle with strikes continue to struggle with strikes. It was just a way of playing the odds. So often, wishing for a pitcher to show better control is like wishing for a hitter to show better discipline. Those improvements are relatively rare.

They do happen, though, and often enough that optimism isn’t unwarranted. The Blue Jays wanted to see if Sanchez would find a way to more consistently own the zone. With strikes, Sanchez would have significant upside. The Jays went for it, and, wouldn’t you know it, but Sanchez has been utterly fantastic. Last year’s starting experiment is now a distant memory, as Sanchez is in the process of establishing himself as one of the more electric young starters in the league.

Sanchez frustrated the Tigers on Tuesday, and though the Blue Jays ultimately didn’t get the result they wanted, the Tigers spoke glowingly of Sanchez after the fact. It doesn’t get better than an endorsement from Miguel Cabrera.

“Oh my God, unbelievable,” Tigers slugger Miguel Cabrera said. “Whew. Wow. Very impressed. Very impressed. … To pitch over 95 mph for eight innings, that’s impressive, with a good breaking ball. He showed a little bit of changeup, but he doesn’t need a changeup.”

Sanchez has maintained his power, he’s broadened his repertoire, and he’s impressed the hell out of a future Hall-of-Famer. We’ve seen Sanchez dominate in relief, but last year out of the rotation, he allowed a .346 OBP, and a .392 slugging percentage. This year, his numbers as a starter are at .285 and .321, respectively. There’s another way of showing this. Because of Sanchez’s sinker, he’s always been able to generate grounders, but here’s a plot of 2015 starting pitchers with grounder rate and K-BB%:

You see the problem. You already knew the problem. Here’s the same plot, for this current season:

That’s an awfully big shift for that little yellow dot. A year ago, Sanchez was among the league leaders in lowest average launch angle allowed. This year, he’s kept that up. But he’s figured out the zone, and he’s improved his curveball, and so there have been more of the good things and fewer of the bad things. What Sanchez has pulled off, by improving his conditioning and mechanical consistency, is remarkable, and this table can tell you why. Since 2002, more than 1,700 pitchers have thrown at least 50 innings as starters in consecutive seasons. Here are the 10 largest year-to-year improvements in strike rate:

A strike rate of 58% is unworkable. That’s exactly why I wasn’t a big Sanchez believer. But a strike rate of 64% is perfectly average, and then you get to blend in how difficult Sanchez is to square up. All he needs is that league-average strike rate. The rest of the stuff is good enough for him to take off from there.

Improved control isn’t the easiest thing to visualize, but Sanchez has gotten better at pitching to his glove side. Here is where Sanchez’s pitches have gone as a starter against righties:

This is from the catcher’s perspective, by the way. And here is where Sanchez’s pitches have gone as a starter against lefties:

Sanchez has opened up for himself another area, and that implies his greater precision. You might not even really need that to be implied, given the rest of the statistics. It’s pretty obvious that Sanchez has gotten better, and he’s gotten better by putting a greater number of his pitches around where he intends. It’s simple, but no one has doubted the quality of his tools. These days he knows how to use them properly.

I’ve saved the most exciting thing for last. Sanchez, of course, has generated all those grounders. Even as a starter, he’s still thrown 74% fastballs. And he has a 68 FIP-, which is right in line with his ERA and xFIP. As a little experiment, I gathered all starter-seasons since 2002 with at least 50 innings. Then I ran some easy math to identify the most similar seasons to Sanchez’s 2016, based on grounders, fastball rate, and FIP-. The top five most similar campaigns:

Those are some excellent sinker-ballers, with Webb included twice. Of course, the method is selective for excellence, because it includes an excellent FIP-, but this is an indication of what Sanchez might be becoming. He still isn’t all the way proven, and he still isn’t all the way stretched out, but he’s on path to become one of the best sinker-ballers in the game. Webb figured out strikes for good at 26. Brown figured out strikes for good at 27. Halladay figured out strikes for good at 24. Hudson figured out strikes for good at 25. Sanchez turns 24 in a few weeks. There’s precedent for this, and the precedent is exciting.

Already, we can say that Aaron Sanchez looks like an ace. That doesn’t mean he’s yet achieved ace-hood, but the latter does eventually follow from the former, provided the former continues long enough. That’s what’s ahead of Sanchez now. It’s a hell of a lot better than working in the bullpen.