On the afternoon of Monday, June 21, umpires intercepted Mets ace Jacob deGrom on his way back to the dugout after a 1-2-3 first inning. They checked his glove, checked his hat, and checked his belt buckle. Then deGrom, the first pitcher to be inspected as part of Major League Baseball’s beefed-up (read: actually enforced for the first time) anti-foreign-substance policy, went about his business, throwing four more scoreless innings before his day was done.
Wednesday marked one month since the sticky-stuff crackdown went into effect. And for the most part, the league as a whole has gone about business as usual too. After a few early hiccups, umpire inspections soon seemed routine and receded into the background. And although the enforcement plan lowered spin rates as intended, the impact on the pitcher-batter battle has been somewhat subtle, neither confirming fears that a lack of non-rosin sticky stuff would prevent pitchers from doing their jobs nor fulfilling hopes that contact and offense would bounce back in a big way. Essentially, the absence of (or reduction in) foreign substances turned the clock back a bit—just not so much that anyone would notice without a close look at the data. In one month, sticky stuff has morphed from an all-consuming story to … well, not a non-story, exactly, but an unobtrusive part of baseball’s background noise.
It’s too early for conclusive answers to every question we had about sticky stuff, but it’s not too soon to pick up on any pronounced trends; if pitchers really couldn’t control the ball or miss bats without banned substances, we would be able to tell the difference right away. Although the leaguewide spin rate started sinking in late May, the decline picked up speed in early June, around the time it became clear that MLB—which had sent two previous memos about taking sticky stuff more seriously—was about to take action for real. Most of the drop happened prior to inspections starting, although the average continued to tumble in the immediate aftermath of June 21.

Through June 3, when word leaked out of an MLB owners meeting that the league had decided to get serious about sticky stuff, the average four-seam fastball spin rate was 2,318 revolutions per minute. From June 4 through June 20, the day before the umpire inspections started, the average was 2,268 RPM. From June 21 through this Tuesday, the first 30 days of MLB’s official, no-foolin’, no-substances-allowed era, it was 2,231 RPM. It’s tough to draw clean lines leaguewide between “with sticky stuff” and “without sticky stuff,” because pitchers who were using banned substances gave them up at different times. But the difference in four-seam spin rate between the baseline through June 3 and after inspections started is 87 RPM. Depending on one’s point of view, that’s either a lot or a little.
It’s a lot in the sense that the sticky-stuff crackdown essentially wiped away several seasons’ worth of spin-rate gains (whether obtained through the use of foreign substances or via teams targeting pitchers who naturally had high spin). The average spin rate since June 21 has been lower than it was in 2015—and on average, pitchers throw harder now than ever, which means that the current ratio of spin to velocity is lower than recent seasons’ to an even greater degree.

In other words, the sticky-stuff crackdown achieved its superficial goal: Judging by spin rates, it appears pitchers really did stop (or significantly cut down on) using foreign substances. Unsurprisingly, that use seems to have been pretty pervasive. Through Tuesday’s games, 291 pitchers had thrown at least 50 four-seam fastballs both through and after June 3. Of those, 226 (77.7 percent) had a lower spin rate in the latter period, and 243 (83.5 percent) had lower velocity-adjusted spin. If we instead compare stats through June 3 to those from June 21 on, we find similar rates of decreasing spin and speed-adjusted spin: 78.9 percent (179 of 227 pitchers) and 81.1 percent (184 of 227). Those numbers would seem to support pre-crackdown estimates that 70 percent of pitchers or more were using something illicit.
Then again, comparatively few pitchers have suffered the steep drops in spin that would be consistent with weaning oneself off the most potent grip/spin-enhancing substances, which some tests suggest can add hundreds of RPM. Of the 291 pitchers who threw at least 50 four-seam fastballs both through and after June 3, only 136 (46.1 percent) lost 50 RPM or more, 72 (24.7 percent) lost 100 RPM or more, 22 (7.5 percent) lost 150 RPM or more, and 11 (3.8 percent) lost 200 or more. For the 227 pitchers who threw at least 50 four-seamers through June 3 and after June 21, those figures are 115 (50.7 percent), 74 (32.6 percent), 35 (15.4 percent), and 15 (6.6 percent), respectively. Either the most egregious offenders have come up with a way to conceal Spider Tack from the umps, or not that many pitchers were abusing it in the first place. (Maybe the inventor of Spider Tack said he wasn’t aware it was popular in baseball because it wasn’t all that popular.) Thus, the leaguewide reduction in spin, while widespread, has been a little less precipitous than some estimations of the state of sticky-stuff usage might have had one believe.
Of course, spin is mostly a means to an end, and we pay attention to it only inasmuch as it produces different outcomes. On an individual level, it’s hard to draw a direct line between spin-rate reductions and pitcher performance. Oakland A’s righty James Kaprielian—by some measures the pitcher whose spin has sunk the most—has posted a 2.51 ERA (with more than a strikeout per inning) since June 3, and an even more minuscule 2.40 ERA after June 21. And Gerrit Cole and Lucas Giolito, who weeks ago found themselves at the centers of scrutiny surrounding their diminished spin rates, seemed to struggle initially but have been brilliant their last two times out.
What we can say for certain is that ultra-high-spin pitches have gotten much more scarce: Offerings with spin rates of 2500 RPM or more have made up only 5.2 percent of four-seamers since June 21, compared to 15.4 percent through June 20 and 16.7 percent through June 3. And as a group, pitchers who lost 200 or more RPM on their four-seamers through and after June 3 and June 20 have performed worse after cleaning up their acts, though even their post-sticky-stuff stats haven’t been bad.
Pitchers Who Lost ≥200 RPM Through/After 6/3 and 6/20
To get a feel for the full impact, we have to look at the league on a collective level. The main impetus for MLB’s midseason move to eradicate sticky stuff was the offensive downturn that dominated the news during the no-hitter-happy start of the season, as strikeout rates continued to climb and a slightly deadened ball made contact a little less rewarding. Since spin rates started receding, offense has increased considerably—but so have temperatures across the United States, a confounding factor that always juices scoring as the season wears on. To assess the impact of the banishment of sticky stuff, we have to compare this season’s offensive improvement to the typical uptick at the same time of year.
The first table below lists several leaguewide offensive stats (and average game-time temperatures) for a few portions of this season: through June 3, June 4 through June 20, through June 20, since June 4, and since June 21. Focus on the two rows in bold at the bottom, which show the changes in each metric through and after June 3 and through and after June 20. The second table shows the same breakdowns for the four preceding full seasons (2016 through 2019) combined.
MLB Offense Before and After Sticky Stuff Enforcement, 2021
MLB Offense During the Same Periods, 2016–19 Combined
If you compare the last two rows from the first table to the last two rows from the second table, you’ll see that this year’s offensive increase has been bigger than the customary summer scoring boost, though not enormously so. Entering Wednesday, the league’s OPS was up 33 points since June 4 and 31 points since June 21, relative to climbs of 22 points and 15 points, on average, over the same spans in recent seasons. We can’t confidently attribute that difference entirely to sticky stuff, because midseason scoring shifts fluctuate somewhat from year to year. (In 2019 alone, for instance, the increases after June 3 and after June 20 were 27 and 26 points, respectively, not far short of what we’ve seen this season.) But these stats supply some evidence that doing away with sticky stuff has helped hitters.
The shape of the performance change might be more interesting than the (modest) magnitude. The most salient single stat is the strikeout rate, which fell a full percentage point after June 20 (and also after June 3). That’s more than triple the typical midseason decrease in Ks. Thanks in part to that (possibly spin-reduction-driven) change, non-pitchers have struck out less often this season than they did last year. There’s a decent chance that by the end of the season, the overall strikeout rate will be lower than 2020’s, despite the influx of thousands of high-strikeout pitcher plate appearances that weren’t around to inflate the average during last year’s dalliance with the universal DH. A percentage-point drop isn’t much in the grand scheme of things—it’s basically like traveling all the way back to 2019—but after 15 straight seasons of strikeout-rate rises, snapping the streak would be something to celebrate, especially in light of the prospect of pitcher hitting being banished again next year.
Some of those missing Ks have become walks and homers, so the three true outcomes aren’t in any danger of disappearing yet. So far, the absence of sticky stuff also seems to have hiked another defense-independent outcome: the hit by pitch. Although hit by pitches were less frequent from June 4 through June 20 than they had been before, they became more common after inspections started. Again, the difference isn’t drastic, and fans’ fears (and players’ griping) about pitchers being unable to throw strikes or avoid hitting batters have looked largely overblown. However, hit by pitch rates were already at or around an all-time high, so any further surge in plunkings would be unwelcome.
A more positive sign from a health and safety perspective is that there’s little unmistakable evidence of a rash of pitcher injuries stemming from the sudden jettisoning of sticky stuff. In mid-June, Rays pitcher Tyler Glasnow pinned part of the blame for his flexor strain and partially torn UCL on giving up sunscreen and rosin, and there was reason to think he had a point. But according to data provided by Derek Rhoads of Baseball Prospectus, the already-rapid paces of non-COVID-related pitcher injuries and pitcher arm injuries haven’t hugely picked up of late (though they haven’t eased up, either). The concern now is whether the heightened fatigue that can come from gripping a ball harder to compensate for less sticky stuff could take a toll later in the season.


If we squint, we can find other indicators of a post-sticky-stuff effect. Movement on some pitches (particularly four-seamers) may be slightly down. The whiff-per-swing rate on four-seamers has dropped by 1.4 percentage points, and by more than 2 percentage points on pitches in the upper third of the zone, where high spin rates are extra beneficial. Perhaps that helps explain why sinker usage is slightly up. All in all, though, these aren’t obvious symptoms. Aside from the inspections, one wouldn’t easily be able to distinguish a sticky-stuff game from a sans-sticky-stuff game. That’s largely a good thing, in that the worst-case scenarios have all been averted. But while leveling the playing field, heading off any further escalation in the sticky-stuff arms race, and arresting the ascending strikeout rate without changing any rules are all reasons for MLB to be happy with how this has turned out, a more substantial recalibration of the sport’s aesthetics will require continued intervention, such as moving the mound back. (Speaking of which, the independent Atlantic League’s mounds are due to move back by a foot on August 3.)
Because the reality of baseball without pitchers applying foreign substances is less intriguing than the speculation leading up to the crackdown, the subject of sticky stuff has largely fallen off the radar in less than a month. In the first few days of enforcement, the novelty of umps frisking pitchers kept sticky stuff front and center, made more prominent by a series of contentious, comedic spectacles: Max Scherzer’s feud with Phillies manager Joe Girardi; Sergio Romo’s dramatic disrobing, Shohei Ohtani’s good-natured compliance, inspections of knuckleballers and position-player pitchers. Amid the uproar and predictions of additional drama, Commissioner Rob Manfred maintained that the fuss would soon settle down, and it did. Only one pitcher, the Mariners’ Héctor Santiago, has been ejected and suspended for violating the rules, seemingly not because he was using something illegal, but because he had a legal substance (rosin) in an illegal location (his glove).
On June 23, author Brendan Donley started the @StickyCheck Twitter account to document and capitalize on the viral visits from umps. He quickly gained tens of thousands of followers, but the games haven’t provided as much primo material this month. “[The] interest and ‘hubbub’ [have] softened a bit, as it’s less of a topic in baseball news, less talked about on broadcasts, [and] the players affected no longer have their hackles up when umpires approach them coming off the mound,” Donley says via direct message. He adds that “the same goes for fans getting used to the sight of these ‘sticky checks,’ with that first impression of awe and comedy wearing off a bit.” That deepening apathy is evident in data from Google Trends, which shows searches for “sticky stuff” and “foreign substances” ramping up throughout June and peaking soon after enforcement started, before nearly flatlining lately.

Hitters, pitchers, and front-office analysts are still acclimating to life without sticky stuff, which makes this a clear case of “further research required.” But based on what we’ve seen so far, pitchers have had much more going for them than sticky stuff alone: increased velocity; improved pitch design, pitch selection, and pitch location; less exposure to opponents within the same game; more efficient framers and fielders; and so on. Many hitters have said that they’ve noticed little to no difference in pitch quality; as Joey Gallo told CBS Sports, “Guys still have ridiculous stuff.” The league may yet develop a legalized substance or adopt a pre-tacked ball to take the place of exiled sticky stuff, but in the warm weather, at least, the need doesn’t seem so acute.
In light of the above, allow me to present a unified theory of baseball rule-breaking: Cheating is overrated. Not because guilt prevents cheaters from enjoying their ill-gotten gains, but because those gains are generally smaller than the cheaters (and the cheated) believe.
Let’s review some recent scandals, all of which have been enabled by conditions MLB helped create. Study after study (after study after study) has concluded that the Astros probably didn’t derive any overall benefit from their sign-stealing scheme—and the Astros’ sign-stealing solution was more sophisticated than the untold number of lower-tech sign-stealing approaches that preceded (or overlapped with) Houston’s. The Braves broke international signing rules to add teenaged talent to their organization, and none of the prospects they signed (and subsequently lost) look like standouts today. (According to FanGraphs lead prospect analyst Eric Longenhagen, there are “no stars or even everyday-type players” in the group.) Even steroids, which certainly benefited some players, likely had little to no effect on others. PEDs probably didn’t turn many (or any) players from scrubs into stars, and other factors may have been just as responsible (if not more so) for the offensive inflation of the late 1990s and early 2000s.
I’m not saying cheaters never prosper; of course crime pays sometimes. I’m saying most forms of cheating in baseball—and perhaps in all sports—are more scandalous than they are efficacious. That doesn’t mean they aren’t morally wrong, that they can’t cause harm, or that teams and the league shouldn’t take steps to prevent them. But because they’re juicy stories, we probably pay more attention to their on-field implications than they strictly deserve.
The irony of all of this is that the cheaters are so often naturally great. Maybe the same passion and competitiveness that push elite players to train hard also make them more likely to seek out edges that go against the rules. Maybe teams on the brink of victory are more likely to look for any help over the hump. But Barry Bonds was an all-time great even when he was clean. The Astros were (and are) excellent hitters. The Braves’ rebuild would have worked anyway. None of them had to hurt others, or their own reputations, to get good.
Similarly, most pitchers who dabbled or indulged in foreign substances probably weren’t successful because of sticky stuff, even if it helped them here and there. Now they’re trying to prove—to fans, to hitters, and to themselves—that they never needed the goop. The better they do that, the less of a story sticky stuff will be. As Marcus Semien said, “Pitchers are gonna be good regardless. Pitchers are good without it.”
Thanks to Lucas Apostoleris and Derek Rhoads of Baseball Prospectus for research assistance.