Coming into 2017, Michael Wacha’s role was up in the air. There have always been questions about his durability, and his 2016 ERA was over 5. This year, calls to move him to the bullpen peaked in late June, after a six-start stretch when Wacha failed to get past the 4th inning five times. After his start against Philadelphia on June 21, he had a 4.76 ERA.
As of this writing, Wacha’s ERA is down to 3.71 (35th among qualified SP), and he owns a sparkling 3.32 FIP. That FIP is best on the Cardinals, and 13th among qualified SP. He has 2.1 fWAR in 94.2 IP, which, just to give you an idea of how good that is, pencils out to 4.5 fWAR per 200 innings. Wacha’s pitched at an All-Star level this year.
What’s going on here?
As with all pitchers all the time, a large part of the answer is going to be “we don’t know.” Maybe his arm feels good for the first time in a while, or there’s a mechanical tweak to credit, or something has changed mentally for him. The best we can do is look at the observable data we have, and see what it tells us.
Conclusion 1: A lot of it might just be noise.
Wacha’s season-by-season ERA looks like a guy who was lost and now is found:
But his annual FIP paints a different picture:
FIP makes Wacha look like a guy who fell off toward average after a great debut, but has stayed consistently better (at least a little) than average. Viewed through the lens of FIP, Wacha’s 2017 performance is an improvement over last year, yes, but it’s somewhat more modest than the story told by his ERA. And when you add in xFIP (which attempts to eliminate the noise introduced to FIP by short-term peaks and valleys in a pitcher’s home run rate), Wacha’s rebound looks even more modest:
Wacha’s peripheral stats back up the idea that his collapse was overstated in the first place. Most notably, last year Wacha gave up the worst BABIP and LOB% (percentage of runners allowed who were stranded) in his career:
The unusually low strand rate looks like nothing but bad luck, i.e. the hits Wacha gave up came a bit more bunched up than usual. And there’s a skill to BABIP allowed, to some extent, but .334 would have placed him among the worst (or unluckiest) qualifying SP in 2016. We know the Cardinals had a really bad defense last year, and we also know that sometimes 138 innings of fluky BABIP can just happen for no apparent reason. All of which is to say, if you’re basing your impression of Wacha’s 2016 performance on his ugly number of runs allowed, I encourage you to reevaluate that. There’s a lot of reason to think he wasn’t that bad, and that this year’s much improved ERA is at least in part (maybe large part) an ordinary case of a bad ERA catching up with a good FIP.
Conclusion 2: A lot of it might not be noise.
I’m not convinced it’s all noise, though. It’s pretty easy to dig into Wacha’s 2017 numbers so far and find lots of places of real, albeit small, improvement. After dipping a bit below league average in 2015 and well below last year, Wacha’s strikeout rate has shot up to almost 24%, which is a couple points better than league average and Wacha’s best rate since his rookie season. Wacha’s also gotten hitters to take strikes a bit more than before (65.5% swing rate in the zone vs. 68.4% career), swing and miss in the zone more often (83% contact in the zone, 85% career), and whiff outside the zone more often (69.3% contact out of zone, 70.3% career). These aren’t eye-popping differences, but this stuff adds up to getting in better counts, and getting in good counts matters a ton.
His command also appears to have improved from 2016. We can get a sense of this using heatmaps courtesy of Baseball Savant. Here’s Wacha’s fastball placement over the last two years:
It doesn’t take special training to read these; you can tell at a glance that Wacha’s doing a better job this year hitting the edges on his arm side (and avoiding the middle) with his fastball.
Similar story with the cutter, thrown almost exclusively to the glove side:
And the changeup, which he tries to throw for strikes on the arm-side corner or bury out of the zone as a put-away pitch:
Each of those tell a similar story: Wacha’s hitting his spots and staying out of the middle of the plate better in 2017 than he did in 2016. That gives us a credible performance-based reason to conclude Wacha’s bounce-back 2017 isn’t all noise. And then there’s his fourth pitch…
Conclusion 3: Michael Wacha has a real curveball now.
Wacha broke into the league with a hard, heavy fastball and a wipe-out change. His curveball was mostly regarded as a show-me pitch (although some scouts believed it would or at least could be plus). From his debut through 2015, Wacha’s curve generally got between 5 and 6 inches of vertical break, per Brooks Baseball. That’s not bad, at least not if you throw it hard (like Lance McCullers) or with pinpoint command (like Max Scherzer). Mike Wacha has historically done neither of those things, though.
In 2016, Wacha’s curve picked up about an extra inch of drop. So far this year, he’s shown even more improvement—he’s now averaging just over eight inches of vertical break. To benchmark that against some other pitchers who throw curves at similar velocity: that’s more drop than curveball maestro Rich Hill gets, and it’s comparable to Jake Arrieta or Adam Wainwright (though both of those guys are down slightly from their peaks). Granted this is a pitcher swinging, but here’s Wacha snapping off one of those 8” curves this year:
He’s doing a better job spotting it, too (again, credit to Baseball Savant):
Wacha still rarely throws curves. Still, the improvement in Wacha’s curveball from a raw stuff perspective, paired with the increased command he’s shown with his entire arsenal this year, makes his bump in performance this year one of the more intriguing storylines on an often not-so-intriguing club. Wacha was never as bad as his ERA last year made him look. He probably wasn’t bad at all. But even factoring that in, he’s gotten better this year.
With sharper command and a weaponized breaking pitch, Michael Wacha suddenly looks like a guy with three plus pitches that he can spot. That ought to catch the attention of even the most despondent Cardinals fans—and maybe some teams around the league looking to add an arm.
Now he just has to stay on the mound.