Trevor Bauer’s Spin Still Doesn’t Quite Add Up

Trevor Bauer's spin is down—but not as much as it probably should be.

Shoutout to whoever had money on Hector Santiago as the first sticky-substance-based ejection of this bizarre season. There are tons of players who have a lot to lose (or gain) from these new rules, and we’ve speculated about them ad nauseam. One can only sit back and laugh because goodness knows Hector Santiago wasn’t one of them, though he is having a fine season so far out of the Seattle bullpen.

I’ll spare you most of the background reading. By now, a considerable amount of ink has been spilled on the play-by-play of how we got here. Now, a bit more than a week into the new regulations, it’s becoming clear just how precipitous the league-wide drop in spin has been, and that there will be significant consequences thereof. Naturally, our attention goes deeper than league-wide numbers. We’re interested in the individual players who have the most to gain and/or lose from the increased scrutiny.

Amid the great sticky stuff crackdown of 2021, few players have been discussed more than erstwhile teammates Gerrit Cole and Trevor Bauer, who have become poster boys for the entire debacle. Cole famously rode increased spin to one of the most dominant stretches of pitching in recent memory—and a $300 million contract. Bauer, of course, was until recently an outspoken opponent of such practices and bears much of the responsibility for bringing the issue into public discourse.

In spite of MLB’s hamhandedness in implementing these rules, it seems to have leveled the playing field to some degree, which, at the end of the day, was the desired outcome. But that may not entirely be the case. While Bauer’s spin rates certainly decreased significantly in his first start after enforcement began a week ago, they remained suspiciously high—too high, for what we know Bauer’s established baselines to be.

This might seem somewhat contradictory. Again, like Cole, Bauer has frequently been cited as one of the biggest losers of the crackdown. In terms of raw numbers, that’s correct. Because raw spin numbers are dependent on velocity, the best way to assess who is gaining or losing spin is by simply dividing spin by velocity to get a number that some have taken to calling Spin Velocity Ratio (SVR). Even by that measure, Bauer has in fact been one of the biggest droppers of the ordeal among pitchers who threw at least 200 four-seamers before the day of doom.

Biggest Four-Seam Spin Decreases Post-6/21

Of course, this didn’t start just on the 21st, either. If we move the date of the split back to June 4th, the day after it was reported that front offices had been informed of the impending crackdown, no pitcher has lost a greater amount of spin relative to their velocity than Bauer.

Biggest Four-Seam Spin Decreases Post-6/3

What’s fishy about this? Once again, the issue is that when it comes to assessing whether a player is gaining a super unfair advantage through the use of adhesives, there’s still more context than velocity and pitch type.

We now know very well that fluctuations in spin rate are the primary canary in the coal mine for sticky shenanigans, and we also know that there’s more or less no way to naturally increase one’s spin rates without those sticky shenanigans. That being the case, it stands to reason that the veteran pitchers whose spin rate increases were documented in real-time ought to now be returning to their previously established baseline levels of spin—or even a little lower, given that the blanket ban includes sunscreen, as well.

Cole has been picked apart on the topic more than just about any other pitcher on this side of Bauer, and he seems to be a textbook study of how MLB’s policy should be playing out (in theory).

Gerrit Cole Career Spin Rates

While it still remained slightly elevated, Cole’s pitch data from his June 22nd start has the look of a pitcher returning to what we know for a fact they looked like before they started using super adhesives. Similarly, looking at Dylan Cease—Rob Manfred’s biggest victim since the start of frequent umpire checks—we see an even more stark return to “normal” without any tack.

Dylan Cease Career Spin Rates

Moving over to the National League, we can see the same effect in Brandon Woodruff, who I identified before the season as someone who stood to lose a fair amount of ground if a crackdown should take effect.

Brandon Woodruff Career Spin Rates

Once again, here’s someone very clearly resembling what they looked like for most of their career, even if, as with Cole, the return to 2019 levels of SVR rather than the consistent marks he posted in 2017/18 still looks a bit suspicious.

Finally, for good measure, we can see another easy case study in Bauer’s Dodger teammate Walker Buehler, who is clearly suffering from the lack of even a sunscreen-based concoction.

Walker Buehler Career Spin Rates

All that being said and shown, it should be quite clear that something isn’t quite adding up with Bauer.

Trevor Bauer Career Spin Rates

Whatever he’s doing and however he’s doing it, as much as I hate this phrase, the numbers don’t lie. Though the slow and steady rise of Bauer’s spin rates is as old as Statcast, we can say with certainty that those 2015-2018 spin ratios are more or less what Bauer looks like when he’s not using something sticky. This isn’t me speculating, it’s by his own admission. In addition to being stated in numerous interviews and tweets over the years, Bauer wrote the following in a Players’ Tribune article published in February 2020. 

In the face of all the drama invoked by this controversy, the suggestion that a pitcher is still trying to drastically circumvent the rules doesn’t come lightly. However, it’s difficult to come up with an alternative feasible explanation for the spin numbers from his June 23rd start. Like I said earlier, spin numbers can fluctuate in the vicinity of 50-100 RPM for a number of reasons, and sometimes they can vary a bit game by game. But what Bauer did last Wednesday would have been unprecedented for him even prior to his “experiment.” Between the 2015 and 2018 seasons, when Bauer was admittedly chasing spin without resorting to something Spider Tack-esque, only once did he achieve an SVR higher than 26, much less the 27.25 we saw the other night.

Bauer Top Starts By SVR 2015-2018

As a matter of fact, we don’t even have to guess at what Bauer’s baseline is, and whether this is unusual. Take it from the man himself!

Given all of the above information, there are two conclusions that one can come to: either Bauer has cracked the code to increasing spin without substances and hasn’t shared it with anyone—which, although it would generally track with Bauer’s character, would likely be too monumental of a discover to keep a secret for long—or he’s managed to evade umpire checks to continue doctoring the ball in some manner. Take your pick.

Again, this is not a suggestion that should be made lightly. If he is in fact continuing to doctor the ball, I can’t speculate on how he might be doing it. If it escapes the umpire’s gaze, it’s probably escaping the gaze of the TV cameras too, and I can’t do anything more than guess about what Bauer is doing when he isn’t on the mound, and they wouldn’t be very good guesses. All I can do is present the numbers, present what we know about those numbers and what they mean, and draw conclusions from there.

I don’t necessarily mean to single out Bauer, either. There may be other pitchers out there who are also occupying an inexplicable middle ground between their old and new spin rates. However, there’s a fair argument to be made that this wouldn’t be happening had Bauer not decided to very loudly make a public issue of it and declared himself too “moral” to partake in it. Between that and the bare nakedness of the ball-doctoring that helped him to the 2020 NL Cy Young award, it’s natural that he falls under closer scrutiny than most.

Finally, few articles about Bauer and his activities would be complete without contextualizing them with what we know about him as an individual off the field. Bauer has repeatedly displayed a penchant for bullying, discrimination, hypocrisy, and an unwillingness to take responsibility for his actions. It is difficult, if not impossible, to fully account for these baseball-related developments outside of that lens. Simply put, if there are borderline-irrefutable numbers that suggest that he is subverting the rules even after helping to engineer a crackdown on his peers, he’s given us little reason to extend him the benefit of the doubt.

With all this in mind, witnessing the melancholy and frustration that has been bared to the public from pitchers including Tyler Glasnow (whose takedown of the blanket substance ban is a must-watch, if you haven’t seen it already) and Garrett Richards leaves a foul taste in my mouth. Players are getting injured, and livelihoods are being affected. One would be hard-pressed to describe the proceedings of the past month as good for baseball, in spite of the best intentions of those who wanted a more level playing field. Bauer advocated for it years ago, and it’s what we’re finally getting. As of his last start, however, it’s unclear whether he believes that should apply to himself, or just everyone else.


(Photo by Brian Rothmuller/Icon Sportswire)

Zach Hayes

Zach is based in Chicago and contributes analysis and coverage for Pitcher List and South Side Sox. He also co-hosts the Shaggin' Flies podcast with Ben Palmer, and enjoys reading, Justin Fields highlights, and people-watching on the CTA.

4 responses to “Trevor Bauer’s Spin Still Doesn’t Quite Add Up”

  1. Tired says:

    More Bauer bashing; man this gets old. We know he commits the serious crime of wrong-think, but please, find another villian. There are plenty of guys that commit real crimes that you can try to attack their character with. Why don’t you try it?

    • Zach Hayes says:

      So, just out of curiosity, I’ll bite–what exactly in the article did you disagree with? Is there anything that you can provide counter-evidence for? Or do you just think Bauer should be untouchable?

  2. Really? says:

    This is one of the least professional articles I’ve seen on PL, but I’m not sure whether the plain bias or the flawed analysis is more offensive. I mean, this is genuinely low quality all-around and really reflects poorly on the PL team, and I hope it doesn’t affect their ability to build rapport with pro players in the future.

    I’ll start with the obvious….you’re citing spin data from a single start as the basis for cheating accusations. His fastball spin was in the 2400’s in both his previous and following start, which is an increase of <100 rpm from the career highs you mentioned. That also happens to be within the 50-100 spin rate margin of error you mentioned, but let's draw sweeping conclusions anyways….? The data you left out doesn't really support your analysis but then again, your conclusions seemed to be well-formed before you even wrote the title.

    The thing that gets me is that you're well-aware of the faults in your assessment, but then you ignore them all to arrive at cheating accusations against arguably the most transparent player in baseball. I mean, what exactly are you implying here? Are you making the case that Bauer near single-handedly pressed the issue of sticky stuff with MLB for years in order to level the playing field so he could implement his own convoluted method, after resisting cheating altogether for the first half of his career? Or is it more likely that an obsessive pitcher was able to add ~100 rpm to his fastball over 3 years of tinkering? Did you try and establish precedent for players achieving those gains, or did you think it would be relevant to the reader that Bauer's current rpm and his post-substance decline are well-aligned with the rest of the league?

    Really disappointing effort.

  3. Wired says:

    Not going to try and argue with any of the above, but I think that you were pretty fair in your analysis. I think the points you raise are valid, and when articles from websites like pitcherlist/fangraphs/any website doing data analysis on baseball, outliers are really the name of the game. The second to last chart you have there is pretty crazy looking, and by his own admission, is a smoking gun.

    Looking at Bauer’s past is also not beyond the pale, and should be taken in to consideration when discussing this issue specifically.

    Anyway, think that you’re post was cool

Leave a Reply

Your email address will not be published. Required fields are marked *

Account / Login