A Sticky Situation: How foreign substances changed baseball forever

By Jack Byrne

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In baseball, the game of chess between a pitcher and hitter is the most complex exchange in sports. 

At 60 feet and 6 inches, it is a small yet unforgiving distance. Hitting a baseball is the most difficult task in the sporting world; a round surface attempting to hit a round ball, both of which are moving at the speed of a train. 

Millimeters and fractions of a second have the utmost impact on a game, season and even careers. For years players have tried to find ways to get a competitive edge. This came in the form of sticky substances for pitchers - tacky materials that dramatically improved pitchers grip and turned the modern game into a high-velocity, high-spin game defined by strikeouts. 

As of 2021, the MLB decided that pitchers had abused this grey area within the rulebook and began to crack down on foreign substances with the goal in mind to restore competitive balance and give the hitters their fair shot. But did it work? And how did this affect pitchers at all levels going forward? 

Drawing on Statcast Records, Baseball Reference, Fangraphs data sets and former MLB pitcher and Boston Red Sox pitching coach Dave Bush, this story examines the effect the sticky-substance era had on baseball and how pitchers have responded. While sticky substances gave pitchers a substantial advantage, it is clear that the effects of the ban were not permanent. As the game advanced, new pitchers who never used substances arrived, old pitchers adapted and much of what was lost at the time of the ban has slowly been reinvented in a fair and natural form. 

The Rise and Fall of the Substance Era 

Pitchers using substances to enhance their grip have been around for the entirety of the history of baseball. The modern sticky-substance era started in 2018. That is the year when pitchers' spin rates - a measurement of how many times a ball rotates on its way to the plate, directly resulting in vertical and horizontal movement - were climbing rapidly across the entire MLB. 

By 2019, it was clear that the MLB had a problem on its hands and it began closed-door conversations in the front office about what it could do about it. Offensive output had dropped to the lowest point since 1969, which is when the mound was lowered, with batting average dropping to .245 in 2020 and hitters such as 2015 AL MVP winner Josh Donaldson telling the media they had no chance to compete against these substances.

Bush, who served as the Red Sox pitching coach from 2020-2023, described the phenomena.

“(Sticky Substances) allow you to get the same grip without applying as much strength and if you have to really grip a baseball, then your arm won’t be able to move as fast. It allowed guys to put more force and more spin on the ball without putting as much effort into it,” Bush said. 

In other words, the substances gave pitchers an immeasurable and significant performance boost. When asked about the widespread usage of substances, Bush said, “I hesitate to put a number on it because a lot of guys were quiet about it, but my hunch would be more than half (the pitchers in the MLB).” 

The MLB finally intervened on June 21, 2021, issuing a strict rule change. This memo changed the game of baseball overnight. 

Atlanta Braves Pitcher Max Fried is checked in between innings on June 30, 2021. (Photo by Rich von Biberstein/Icon Sportswire via Getty Images)

Pitching Dominance Before the Ban

League-wide data from 2018-2024 illustrates one of the clearest statistical shifts in MLB history. Across the MLB: 

• Spin rates reached all-time highs

• Strikeout rate increased every year and also reached an all-time high at just under 24% in 2021. 

• ERA fell, especially among those who are “spinners” - pitchers who rely heavily on creating spin and movement in order to be effective. 

Statcast data reveals that fastball and breaking ball spin rates were both at their highest ever recorded in 2020 and off-speed spin rates peaked at their all-time high in 2019. 

The league was favored immensely in the pitchers’ favor - and the MLB knew why. 

The Immediate Impact

As soon as umpires began to check pitchers, data changed in real time.

According to FanGraph records, fastball spin rate declined at an unprecedented rate, with league average dropping more than 100 rotations per minute in June alone. Strikeout rate plummeted from its previous record-high. Batting average rose exponentially, recovering nearly 10 points by the end of the season league wide. Walk rates rose as well, exhibiting a struggle with control and grip.

To put it into perspective, batting average rose by 10 points in the second half of the season. According to baseball reference, every point equates to roughly .60 hits over the course of a 162 game season. Ten percentage points raise means every hitter was averaging six more hits per season. Historically, runs translate to roughly one every two hits, therefore meaning that each player was driving in three more runs on average. Three multiplied by nine players in a batting lineup means that teams scored around 13.5 more runs per game in the second half than they did in the first, [3x9=27/2 (second half of season)]. 

Case Studies: 

All of these numbers are outliers from the typical month-to-month variation, which is clearly a direct result of the ban. However, there was one metric the MLB failed to consider when quitting substances cold turkey: injuries. 

Tyler Glasnow, the ace on the 2020 American League champion Tampa Bay Rays, suffered a UCL injury soon after the ban was instituted. The UCL is a ligament in the elbow and injuring it could be influential to a pitcher’s career, as it did for the first man to receive the treatment, New York Yankees legend Tommy John, for whom the surgery is named. 

Glasnow was just one of many who fell victim to the UCL tear immediately after the ban, as the MLB saw 151 Tommy John surgeries in 2021. However, an unexpected outcome is that the average number of injuries dropped substantially after the initial crop. This is likely due to the fact that pitchers are no longer able to push their arms past the limit, therefore, are getting injured at a much lower rate. 

The Rebound

Although the numbers are shocking to look at, the results of the ban are somewhat expected. 

Bush added a footnote on this: “Guys will find some form of workaround, but the ban needed to happen.” 

Work around that they have, according to Statcast data: 

• Spin rate has risen again. Despite initially falling off significantly, spin rate has slowly been climbing due to new techniques and adjustments made by pitchers. 

• Strikeouts are trending back upwards. After a noteworthy falloff in late 2021, strikeout rate (or K%) began to rise in 2023 and many of the best pitchers in the game have reclaimed their previous strikeout numbers. An example of this is Yankees ace Gerrit Cole, an outspoken substance user, who in 2021 led the league in wins, struggled in 2022 and returned in 2023 to win the AL Cy Young Award. 

• Pitch movement improved. Development of pitches seen on Statcast such as sweeper sliders, splitter-changeup hybrids (off-speed) and fastball mechanic developments. 

• The discovery of pitch-tunneling. Historically, pitchers had naturally different mechanics based on the pitch they threw, which could be a giveaway to hitters. The new generation is trained to learn the same pitches while beginning on the same trajectory without changing their mechanics. 

What is Pitch Tunneling?

ERA is no longer at historic lows, but pitchers have adapted to the modern style of the game due to factors like pitch design and mechanics. Recent statistical analyses have shown that the ban caused a disruption to pitchers. However, pitchers learned to adapt and thrive, preventing the ban from causing permanent effects. 

What the Data Shows: 

After examining six years of MLB data across multiple sources, pitcher case studies and expert analysis, several conclusions come to light. 

1. Sticky Substances Provided a Real Advantage 

It is clear from the data collected. Spin rates, strikeouts and pitching mechanics were all artificially replicated during the years where substances were most prevalent. 

2. MLB’s Ban Was Effective At First 

Immediately after the ban spin rates dropped, batting average and ERA rose and the game became more evenly distributed. These statistics demonstrate strategic effectiveness from the MLB. 

3. The Ban Caused an Influx in Injuries in the Short-Term

The Tommy John statistics show that there was a huge impact on injuries among pitchers in the short term, reporting the second highest single-season total ever. However, the substance ban possibly reduced surgeries in the future, as league numbers have steadily declined every year since. 

4. The Long-Term Results Shows Adaptation Over Elimination

Numbers did not stay as low as they initially were following the ban in 2021. Many pitchers adapted their game and mechanics in order to retain their place in the MLB, and those who could not adapt did not last long in the league. Changes in mechanics and pitch arsenals are two ways that pitchers managed to carve out a role in the post-ban MLB. 

The data makes one thing clear: sticky substances absolutely gave pitchers a noticeable advantage during their peak usage from 2018-2021. The MLB was fair and reasonable in banning them. The ban resulted in a re-balancing of the most complex matchup in sports between pitchers and hitters and it directly had an impact on the gameplay. 

However, sports do not change instantly. Pitchers resisted permanent change, learned to adapt in order to find similar success through creativity and implemented mechanical changes largely thanks to pitching coaches around the league, such as Bush with the Red Sox. Today, many pitchers have reached similar, if not better numbers that they were posting before, not through artificial boosters but through the values that America's pastime was built upon. 

In the end, sticky substances have nothing to do with cheating, nor does it take away from the incredible skill it took to pitch at the highest level of baseball during that period. It is a story of athletes reacting quickly and adapting to change, even when the game as they know it is swept out from beneath them. 

The ban worked and the advantage disappeared. However, pitchers scratched and clawed their way back to success.