It’s been less than a week since Major League Baseball made known that it will begin to crack down on the use of foreign substances by pitchers, and it’s possible we’ve already seen some tangible results among some of the game’s most prominent arms. Jorge Castillo of the Los Angeles Times pointed out that the spin rate on Trevor Bauer’s four-seamer in his most recent start for the Dodgers dropped by 223 rpm. Hitters around the league are monitoring such changes, as evidenced by Josh Donaldson wondering aloud when asked by Dan Hayes of The Athletic: “Is it a coincidence that Gerrit Cole’s spin rate numbers went down (Thursday) after four minor leaguers got suspended for 10 games?”

Yankee fans may bristle at seeing their ace called out, but Cole himself struggled to formulate an answer when plainly asked yesterday whether he’d used increasingly potent foreign substances — Spider Tack, in particular — to doctor the ball (Twitter link, with video, via Matthew Roberson of the New York Daily News).

“I don’t quite know how to answer that, to be honest,” Cole awkwardly replied after struggling for several seconds to formulate an answer for the yes-or-no prompt. “There are customs and practices that have been passed down from older players, from the last generation of players to this generation of players. I think there are some things that are certainly out of bounds in that regard, and I’ve stood pretty firm in terms of that, in terms of the communication between our peers and whatnot. Again, like I mentioned earlier, this is important to a lot of people that love the game, including the players in this room, including fans, including teams. So, if MLB wants to legislate more stuff, that’s a conversation that we can have, because ultimately we should all be pulling in the same direction on this.”

Cole didn’t directly address Donaldson’s implication, sidestepping the matter by stating that Donaldson is “entitled to his opinion and to voice his opinion” while attributing his drop in spin rate to poor mechanics in his most recent outing. Of note, the two will face each other in today’s game — a fact Donaldson was surely aware of when he made the comments in the first place. (Cole has struck Donaldson out in each of his first two plate appearances to this point).

Bauer similarly opted not to acknowledge whether he’d used such substances, via Castillo. The right-hander repeated multiple times that the only thing he’s sought since first seeking to bring the issue to light several years ago — before a pronounced uptick in his own spin rate — was for “everyone to compete on a fair playing field.”

“[I]f you’re going to enforce it, then enforce it,” Bauer said. “And if you’re not, then stop sweeping it under the rug, which is what [MLB has] done for four years now. … No one knows what the rules are right now, apparently, including MLB and the commissioner, so it’d be nice as players to know what rules we’re competing by and what rules are going to be enforced because, as everyone knows, a rule that’s written down that is never enforced is not a rule.”

It should be again pointed out that the substances in question track far beyond the historically accepted use of substances like rosin, sunscreen and even pine tar. Hitters generally haven’t minded pitchers using minor substances to improve their grip and gain better control of their pitches. Batters are regularly standing in against 95 to 102 mph fastballs in today’s game, after all; it stands to reason that they’d want pitchers to be able to grip the ball on humid days. But in the past couple weeks, we’ve seen several veteran hitters — Donaldson, Charlie Blackmon and Adam Duvall among them — express frustration with the level to which the use of foreign substances has progressed.

The spin-rate revolution has brought about much more potent substances as pitchers and, importantly, as MLB teams and front offices, have realized the manner in which greater spin creates greater efficacy on the mound. Readers who didn’t see last week’s exhaustive and excellent piece from Sports Illustrated’s Stephanie Apstein, wherein she writes that some teams have gone so far as to hire chemists whose responsibilities include (but are not limited to) developing proprietary substances for pitchers, should absolutely check out her column in its entirety. The Athletic’s Britt Ghiroli also penned a stellar exploration of the topic this week, writing within that some savvier teams have begun distributing tacky substances to pitchers at their lowest minor league levels, in order to avoid a sudden uptick in spin rate when they hit the Majors.

The vast spike in four-seam spin rate has undeniably been a contributing factor — albeit not the sole factor — in the leaguewide uptick in strikeouts and the general offensive malaise that has overtaken MLB so far in 2021. The league-average batting line in MLB right now is a historically feeble .237/.313/.396, and even when removing pitchers from the equation, that line only bumps up to .241/.317/.403. This year’s 23.5 percent strikeout rate among non-pitchers is an all-time record. Consider that even five years ago, the average MLB line was .259/.326/.425 with a 20.6 strikeout rate and that a decade ago, in 2011, the average hitter was contributing a .260/.331/.410 slash with a vastly smaller 18 percent punchout rate.

The lack of offense and the lack of in-game action has been an ongoing problem that commissioner Rob Manfred has repeatedly cited as an element of the game he’d like to improve. However, MLB has done essentially nothing to curb the increasing prevalence of foreign substances used by pitchers, instead focusing on other rule changes —  e.g. batter minimums for relievers, runners on second in extra innings, limiting mound visits, etc. — while neglecting to enforce one that has long been in place but overlooked.

The advent of high-octane grip enhancers isn’t necessarily a new revelation. Eno Sarris has written several pieces on the matter over at The Athletic. Bauer famously conducted a single-inning “experiment” — hat tip to then-FanGraphs scribe Travis Sawchik — to boost his own spin rate for one frame back in 2018 after not-so-subtly calling out Cole, his former college teammate, for his huge spike in spin rate following a trade from Pittsburgh to Houston.

But there are quite likely other elements that have paired with the rising prevalence of Spider Tack, Pelican Grip and any number of other substances that have prompted hitters to begin speaking out. Major League Baseball ostensibly sought to correct the increasingly pitcher-friendly nature of the sport by changing the composition of the baseball itself in 2019. Manfred and league officials, of course, never admitted to such tactics, but myriad independent studies that were published at various outlets all revealed changes to the composition of the ball — at a time that just happened to coincide with MLB’s decision to take on oversight of the production from Rawlings.

Evidence of the 2019 changes to the ball were further felt at the Triple-A level, where an already explosive offensive environment, particularly in the Pacific Coast League, erupted to new heights when Triple-A games adopted the use of the same ball used at the MLB level. Home run records in 2019 were shattered; both the Twins and Yankees broke the all-time, single-season home run record for a team, with Minnesota’s “Bomba Squad” narrowly edging out the Bronx Bombers.

It was reported back in February that the league had informed teams it had now taken measures to swing the pendulum in the other direction, so to speak, altering the weight of the ball and the height of the seams in order to curb the rising number of home runs. Meanwhile, several clubs began storing baseballs in humidors prior to their games.

The extent to which those measures have impacted this year’s plague of offensive ineptitude can’t be known, but it’s hard to assume the dearth of offense is merely coincidental given those changes and the rising use of foreign substances. There have already been seven no-hitters this season — I’m choosing to count Madison Bumgarner’s seven-inning no-no; he recorded the maximum number of outs possible, and it’s not his fault the game was shortened to seven frames — and no-hit bids lasting into the fifth, sixth and seventh innings seem to happen multiple times per week.

It’s only natural for hitters to reach a breaking point on this issue. Their salaries are determined by their ability to perform at the plate, and rampant sidestepping of an unenforced rule can only go so far without pushback from those most negatively impacted. That said, it’s also worth pointing out that while everyone has turned a blind eye to this issue, teams themselves could begin paying the price.

Cole and Bauer are going to be the two most talked-about examples, which is somewhat unfair to them given the widespread adoption of this practice, but they’re also prominent data points in this issue for a reason. The Yankees paid Cole the largest contract ever given to a pitcher: nine years and $324MM. The Dodgers gave Bauer the highest single-season salary of any player in MLB history not only in 2021 but also in 2022. Would those same commitments have been made had MLB been actually enforcing its foreign substance rules years ago, rather than further convoluting the issue by tinkering with the baseball itself (and perhaps overcorrecting in 2021)?

Other teams have made weighty financial commitments to pitchers they’ll now have to honor for years to come, perhaps at a time when one of the largest factors behind their success is now something the league suddenly purports to be taking seriously for the first time under the current commissioner. Dylan Hernandez of the L.A. Times recently opined that the Dodgers may not be getting the pitcher they thought they were paying for with Bauer, although Bauer himself rightly pointed back to 2018 — when his spin rate was markedly lower and he dominated for the Indians — as a point in his favor. (That, in and of itself, would seem another tacit admission of his own dabbling in foreign substance use.)

But Bauer and Cole are only two pitchers, and if there is indeed a widespread reckoning for tacky substances on the horizon, other names are inevitably going to be thrust into the spotlight even if they were merely going along with an issue the league had indirectly told them it didn’t consider serious enough to police. ESPN’s Jeff Passan points out that the average four-seam spin rate in MLB has jumped by 79 rpm since 2015, while the average rpm for sliders, curveballs and cutters have increased by a measure of between 200 and 350 per pitch.

That average can be misleading, as well; MLBTR’s Tim Dierkes notes that Bauer’s 2,438 rpm average spin rate in 2018 (prior to his spike) ranked 11th at the time but would only rank 27th in 2021. (Similarly, Bauer’s 2322 rpm average four-seam fastball spin in 2018 ranked 24th, but that mark would come in just 61st this season). The more aggressive adopters of foreign substances have benefited at an increasingly disproportionate level.

Time will tell just how heavily MLB will enact its newfound enforcement of a long-standing rule. Some pitchers will likely cut the act right now, and while a dip in their spin rate may prove telling, they’ll merely be viewed as participants in a trend that had become pervasive throughout the league. Others yet may try to seek more creative methods to cover their use of substances, particularly if MLB’s disciplinary measures prove to be timid. For the time being, there are going to be a whole lot of eyes on tonight’s Donaldson/Cole matchup and probably a big uptick in traffic at Baseball Savant as the focus on spin rate soars to new heights.