There was a time not that long ago when Masahiro Tanaka was one of the most exciting players around. He was then a new import said to throw the world’s best splitter, and though many lamented he just wound up on the Yankees, the most important thing was to see how he did. Tanaka, toward the beginning, was must-watch baseball. But we all move on fast these days. Tanaka pitched well, but in a way that resembled other players we’ve seen. Novelty wore off, as it always does. And then there was the matter of the elbow ligament. Tanaka has pitched through a tear, and I suspect people out there are afraid to embrace him, fearing surgery could be needed at any moment. That fear has legitimacy, but it would be legitimate with any pitcher.

We’re 71 regular-season starts into Tanaka’s big-league career. He’s run an ERA 23% better than average. This year, his numbers are no worse than they were when he was a rookie. Sure, the strikeouts are down, but so are the dingers, and this is a hell of a year to experience a dinger reduction. Tanaka, ever so quietly, has positioned himself as a contender for the American League Cy Young Award. He remains worthy of your attention. And helping to fuel Tanaka’s big year is that, for the first time, he’s throwing a successful fastball.

Tanaka’s average fastball velocity hasn’t changed. At least, not in a positive direction. And he still pitches around his fastball, such that it accounts for just a third of all of his offerings. Tanaka owns a broad repertoire and he makes regular use of every last part of it. The big change here is that, a season ago, Tanaka’s fastball got hammered. Obliterated, more like. This season, not so much. Tanaka hasn’t had to be afraid of the pitch. You can see how that could help a pitcher’s confidence.

You know about our pitch-type run-value statistics. We show overall run values, and we show run values per 100 pitches. In the table below, you’ll see run values per 100 fastballs. There are 85 pitchers who have thrown at least 100 innings in each of the last two seasons. Here are the 10 pitchers whose fastballs have improved the most, at least by their results:

It’s Tanaka in first by a relative mile. There’s nearly a full run difference between him and second place. And to put this in additional perspective — last season, Tanaka had the second-worst fastball on a rate basis in the game. He ranked in the first percentile. So far this year, he ranks in the 82nd percentile. The fastball hasn’t just been less bad. It’s gone from being absolutely awful to something of a weapon.

A weapon, of course, that Tanaka can’t rely on too much. But the fastball is working. To be more accurate, both the fastballs are working — he throws a sinker and a four-seamer. Here is a different way of seeing his fastball run values. Here’s the run value per 100, over rolling 10-start stretches in Tanaka’s MLB career:

Tanaka’s fastball had some problems from the start. Even in his first year, the fastball was below average. Last year, the bottom fell out. This year, there’s been a dramatic recovery. And, I’m sure you’re questioning the validity of the run-value stats. Perfectly acceptable — that comes down to results-based analysis. Why don’t we check with Statcast, and Baseball Savant? Here are changes in exit velocity and launch angle, plotted. This considers batted balls against fastballs, only.

We find Tanaka in the best quadrant. The exit velocity is down and the launch angle is down, which should help lead to fewer extra-base hits. This is all about contact management. Tanaka knows he doesn’t really have a strikeout fastball. He doesn’t need a strikeout fastball, not given his other pitches. He just needs the fastball to not get blasted out of the yard. So far this year, so good.

What’s the deal, then, with the fastball? What has Tanaka done with the pitch? Now it’s time to draw from Brooks Baseball. Tanaka has mixed his fastballs differently, although recently that trend has disappeared:

Before, it was easy to say Tanaka was just using more sinkers instead of four-seamers. And that was true, but the four-seamer has returned in earnest since the All-Star break, and still Tanaka’s fastballs overall have been strong. The way I figure, it’s less about the mix, and more about the location. Here are Tanaka’s four-seamers over the last two years:

Instead of spiking four-seamers or leaving them over the middle, Tanaka now is showing a better ability to pitch around the edges, especially to the arm side. That arm-side edge is vastly preferable to the heart of the zone, and this all blends well with the sinkers:

More of the same, here. Tanaka last year could mostly keep his sinker down and to the arm side, but now there’s more around the edge. It’s not dramatic — it doesn’t reflect some kind of overhaul. But Tanaka has commanded his sinkers better, and he’s commanded his four-seamers much better. When he first came over, Tanaka threw almost all his four-seamers to the glove side. He’s switched that around over time, and though he’ll still go glove side from time to time with either of the fastballs, he’s mostly playing with the arm-side edge. Given his velocities, he has to be fairly precise, but for months now he’s had that precision.

That precision has put Tanaka in the award running. That precision has helped keep the Yankees somewhat improbably in the race. No one has ever questioned Tanaka’s secondary stuff. His secondary stuff is terrific, and it’s allowed him to pitch around his fastball. But now, for the first time, the fastball doesn’t suck. Tanaka has rescued his very worst pitch, and that’s not bad for a guy who most assumed would be rehabbing by now.