Does Adam Wainwright have a spin rate problem?

I imagine the Cardinals slotted Adam Wainwright whey they did in the rotation at least partially to line him up for the home opener on Thursday. Up to less spectulation, however, is that his start over the weekend was far from smooth sailing: 2.2 IP, 7 H, 6 R (all earned), 1K, 1 BB, 1 HR

So what went wrong in Cincinnati? The good news is that there didn’t appear to be any sort of red flag velocity dip for Wainwright.

But if we look beyond the radar gun, there are some more concerning metrics for Wainwright, namely, his spin rate. While not all spin is created equal and can mean different things for different pitchers, it does correlate with a host of benefits for pitchers including missing bats with greater frequency.

For context, Wainwright’s first outing of 2021 ranks, across the board, among his worst since the start of 2019 with regards to spin rate. His single-game curveball spin rate on Saturday was second-to-last (more on that in a bit) and nearly two standard deviations below his mean.

Is this some sort of early-season glitch in Statcast’s data collection? If so, it’s evidently not showing up everywhere. In fact, the leaguewide spin rate on four-seam fastballs this year is the highest it’s ever been. (Granted, a disproportionate share of innings thus far belong to top-of-the-rotation arms.)

I then looked at Wainwright’s first starts from 2019 and 2020, comparing that spin rate data to his end-of-season marks.

Returning to Wainwright’s curveball spin rate, the lowest single-game figure was his first start in 2019, an appearance against the Pirates that saw him last just four innings while surrendering four hits, walks, and runs (all earned) and striking out just three. Even last season when all of his subsequent starts came after the Cardinals’ shutdown and schedule cramming, Wainwright’s spin rate numbers bounced back as the season progressed.

So Wainwright has a track record of underwhelming spin rate numbers right out of the gate, but I couldn’t find any overall MLB trends here. Looking at 2019, below are the average March/April and May-onward spin rates across baseball for each of the pitch types that Wainwright throws.

Curveball: 2514 vs. 2527

Cutter: 2359 vs. 2355

Sinker: 2135 vs. 2137

Four-seamer: 2289 vs. 2288

Changeup: 1810 vs. 1801

Maybe there’s something to be said about breaking balls having it worst, but if we go back to 2018, the average curveball spin rate was identical (2497 rpm) in both time spans. To make things even stranger for Wainwright, his Spring Training spin rate numbers were far more encouraging.

Perhaps there is some sort of technical explanation for what is happening that has nothing to do with Wainwright himself. Or maybe it does have to do with the way he was throwing the ball on Saturday, but he will return to form soon. Or maybe he won’t. Whatever the answer is, the data points provide an interesting question to keep an eye on as the season continues.