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Why MLB had to get a grip on the sticky stuff

Doctoring a baseball is part of the game, but the introduction of Spider Tack made MLB end it. What is it about this goop that’s different? And what does the data tell us?

Story by Alex Speier, Globe Staff
Videos by Christiana Botic, Globe Correspondent

Published July 15, 2021

"Oh, geez – look at this."

As Manny Delcarmen twisted open a canister of Spider Tack, he tried to make sense of the bronze-colored goop that stretched like taffy as he pulled the lid from the container.

The former Red Sox pitcher, along with fellow ex-Sox Lenny DiNardo, had agreed to take part in an experiment at FieldHouse Arena in Easton to measure the impact of illegal ball-doctoring substances. On June 21, Major League Baseball started policing pitchers’ use of sticky stuff that it believed to be a key cause of record-setting strikeout totals.

A container of Spider Tack is opened
Manny Delcarmen opens a container of Spider Tack, the industrial-strength goop that gives pitchers an advantage over batters by helping them increase the spin rate of their pitches. (Christiana Botic for the Boston Globe)

Delcarmen and DiNardo were familiar with traditional methods such as sunscreen and pine tar that are technically against MLB’s rules but historically treated as acceptable.

“Those substances are like jaywalking,” said DiNardo.

But the league cracked down on them in part because of a desire to rein in the use of other substances — including designer products such as Spider Tack — that had been employed with increasing effect in recent years.

Adhesives can improve a pitcher’s grip and make it easier to control pitches. But they also can help a ball stick to the fingertips for an extra fraction of a second – generating higher spin rates that MLB believes have contributed to soaring strikeout totals.

Umpires check Red Sox starter Garrett Richards’s hands for foreign substances on June 28
Since the June 21 crackdown, pitchers like the Red Sox’ Garrett Richards must be checked each inning for foreign substances on their hands, gloves, hats, and belts. (Jim Davis/Globe Staff)

Delcarmen and DiNardo volunteered to throw fastballs with an array of grip enhancers to assist a Boston Globe effort, alongside data from before and after MLB’s enforcement of its foreign substances prohibition, to make sense of the potential impact of what the league had been trying to stop. They weren’t prepared for what they’d encounter.

Spider Tack, originally developed to lift round Atlas Stones in weightlifting competitions, is a substance aptly described as foreign. Sticking five fingers into a jar and then extracting them yields an ornate lattice that looks like a trap in which aliens might feed on prey.

After applying a dab, Delcarmen grabbed a ball and held out his fingers. The ball stuck to them.

“Is that going to come off?” DiNardo asked.

“That isn’t going to rip my fingers off, is it?” wondered Delcarmen.

The ball stuck to Manny Delcarmen’s palm after he applied Spider Tack
After applying Spider Tack to his fingers, Manny Delcarmen found the ball stuck to his palm. (Christiana Botic for The Boston Globe)
Lenny DiNardo shows what Spider Tack looks like.
Lenny DiNardo shows the web-like nature Spider Tack takes when applied to your finger. (Christiana Botic for The Boston Globe)

The history of ball doctoring is roughly as old as baseball itself.

Pitchers experimented with spitballs throughout the 1800s. In the early 20th century, they combined saliva and emery boards (to scuff the sides of the baseball) to increase the level of offense-destroying art.

In the early 1920s, fearful that a lack of offense was eroding the game’s popularity (sound familiar?), MLB prohibited such tactics. Rule 3.01 in Major League Baseball’s Official Rules spells it out: “No player shall intentionally discolor or damage the ball by rubbing it with soil, rosin, paraffin, licorice, sandpaper, emery paper or other foreign substance.”

Yet the use of foreign substances persisted. Some practices – spitballs, the use of Vaseline and slick substances to alter movement, and scuffing – came to be treated as outside the bounds of fair play.

But eventually, an unspoken agreement prevailed. Those who threw potentially injurious objects at high velocities were quietly allowed to use substances that theoretically improved grip and thus enhanced their ability to locate pitches.

Spray sunscreen? Great. Pine tar? So long as not shamelessly flaunted, no problem.

Nick Pivetta rubs down a baseball.
You’ll often see pitchers, like the Red Sox’ Nick Pivetta, rubbing down baseballs between batters. (John Tlumacki/Globe Staff)

Do those substances change the behavior of the ball? Sure. But so does the MLB-mandated doctoring of a baseball.

Rawlings baseballs are hand-sewn in Costa Rica before being packaged and shipped to teams. Out of the box, pitchers consider them nearly impossible to handle.

“Take a brand new baseball, there’s no way you can throw it. I don’t care what you have on your hands,” said Delcarmen. “A regular baseball without mud on it is awful to try to throw.”

For decades, MLB has tried to give the ball tackiness and texture through the application of Lena Blackburne Rubbing Mud, collected from the Delaware River in New Jersey. But the application is inconsistent, and the thin coating of mud represents just a start.

While some pitchers are able to create what they consider adequate grip by squeezing a standard – and legal – rock rosin bag and combining it with some moisture (water or sweat), many pitchers, such as the Red Sox’ Adam Ottavino, have found it inadequate.

“I remember not being able to grip the ball in my third and final career start [with the Cardinals in 2010], panicking about that and several nights in Colorado, and having to ask the older guys how do they grip the ball,” recalled Ottavino.

He was pointed in a standard direction.

“I used sunscreen and rosin pretty much my whole career and a little bit of pine tar – dabbled with that at times in Colorado [where he pitched from 2012-18] and a little bit since,” said Ottavino.

Adding those substances helped pitchers gain adequate grip. But in recent years, the growing effort to quantify everything has led clubs to value a pitcher’s ability to spin the ball more. The consequence? More substances applied to baseballs to increase spin.

Umpires check Gerrit Cole’s equipment
The Yankees’ Gerrit Cole, whose spin rate has dropped since the June 21 crackdown, tosses his glove to an umpire while another checks his hat during a start at Fenway Park in June. (Jim Davis/Globe Staff)

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In recent years, MLB trends were clear and unappetizing.

Steadily, four-seam fastball velocities and spin rates increased. The batting average against four-seamers tumbled while the swing-and-miss rate against them jumped from roughly one of every 12 thrown in 2015 to one of every nine thrown in the first third of this season.

Change in League Batting Average and strikeout ratio over time

High-spin four-seam fastballs thrown with true backspin create lift and minimize sink – creating the illusion of a ball jumping as it crosses the plate. Hitters spend their lives calibrating where a fastball coming out of a pitcher’s hand will end up. Against turbocharged spin, hitters found the ball crossed the plate higher than where they expected it.

Whiff after whiff resulted. Batters became more defensive against fastballs, leaving them more vulnerable to breaking pitches that likewise took on added bite with intensified spin.

Increased velocity accounted for some of the elevated spin rates, but the ratio of spin to velocity both across the league and with many individual pitchers increased too fast to be explained by arm strength alone. Concerns grew that pitchers were using foreign substances.

Some of the concerns related to conventional materials such as sunscreen and pine tar.

“The truth is, even within those two substances, there's varying degrees of how much you're using,” said Ottavino. “You can make sunscreen and rosin unbelievably sticky if you know what you’re doing with it.”

Adam Ottavino gets checked for substances.
The first week the MLB began cracking down, umpires checked behind Red Sox reliever Adam Ottavino’s belt to see if he was using foreign substances. (Michael Dwyer/AP)
The Nationals’ Max Scherzer gets checked for sticky substances.
On June 22, the day after MLB began enforcing substance checks, Nationals ace Max Scherzer wasn’t happy to see the umpires greet him at the mound. (Matt Slocum/AP)

Meanwhile, some pitchers turned to more novel goop such as Spider Tack to generate massive spin increases.

“It was something that pitchers learned how to weaponize and use against the hitters,” said the Red Sox’ J.D. Martinez.

MLB agreed. Desperate to generate more action and more balls in play, the league decided in early June to enforce its ban on foreign substances. Starting June 21, inspections of pitchers for illegal sticky stuff would become routine.

But what exactly were umpires looking for?

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When Delcarmen and DiNardo pitched, a reliever was responsible for packing a backpack every day for his fellow bullpen members. The packing list included daily essentials: snacks, gum, BullFrog sunscreen, and pine tar.

(Christiana Botic for the Boston Globe)

Delcarmen chiefly used rosin and water during his 18-year professional career, occasionally adding a thin coating of sunscreen to his hand on hot days. After he entered pro ball in the Mets minor league system in 2001, DiNardo was introduced to sunscreen and pine tar, which he used throughout his career.

Spider Tack wasn’t in the bag of tricks when they pitched. Both were curious to see how it and other substances would influence velocity, spin rate, and movement while throwing at FieldHouse Arena – an indoor facility with a Rapsodo pitch tracking system.

The pitchers threw fastballs with new, mud-rubbed baseballs, using:

  • Rosin (to set a baseline of velocity and spin rate)
  • BullFrog sunscreen
  • Shaving cream
  • Pelican Grip (a blend of pine tar and rosin)
  • Spider Tack

(Christiana Botic for the Boston Globe)

Delcarmen – who still pitches for the Lexington Blue Sox of the Intercity League – established a baseline of roughly 84 miles per hour with a spin rate of 1,942 RPMs. His velocity remained stable with the BullFrog, shaving cream, and Pelican Grip. His average and maximum spin rates showed a discernible but modest increase with the BullFrog and Pelican Grip while dropping with shaving cream.

DiNardo – who hasn’t pitched in years – threw at a lower velocity (baseline 68 m.p.h.) but with higher spin (an average of 2,053 RPMs) than Delcarmen. His ratio of spin to velocity was extremely high.

With BullFrog, shaving cream, and Pelican Grip, DiNardo’s spin rate actually went down slightly relative to his velocity.

Then came the Spider Tack.

(Christiana Botic for the Boston Globe)

Both former big leaguers were shocked by its appearance, then shocked again by its properties. Delcarmen stuck a ball to his fingers and smirked as it remained attached to them without any support.

“A little scary,” said Delcarmen. “I don't know how you can throw a baseball with that.”

While he struggled to command his pitches, it had an obvious impact. Delcarmen’s average spin jumped by about 7 percent, while he threw one pitch with a spin rate of 2,463 RPMs – nearly 400 RPMs greater than any other pitch he’d thrown.

The experiment: Manny Delcarmen

Results from a pitch tracking system

DiNardo spiked the first pitch he threw with Spider Tack, then discovered a thin layer of the ball’s leather surface had stuck to his fingertips. He struggled to gain a feel that would allow command of his pitches.

“That was way too much,” DiNardo said. “I felt like I was going to throw it either into the floor or through the ceiling.”

Yet even as he threw with some tentativeness, his fastball spin rates jumped. With the rosin baseline, his spin rate (in RPMs) had been 30.3 times his velocity. With Spider Tack, his spin rate averaged 33.6 times his velocity and topped out at more than 36 times his velocity.

The experiment: Lenny DiNardo

Results from a pitch tracking system

Delcarmen and DiNardo said they wouldn’t want to use Spider Tack because it was too difficult to command pitches. (Ottavino said the same recently.) But the jump in spin rate was intriguing.

If a pitcher could acclimate to Spider Tack and throw in or near the strike zone while changing the spin and movement of his pitches …

Then Anthony Sacchetti, a rising senior at Mansfield High School, stepped on the mound. He averaged 78 m.p.h. and 1,443 RPMs when using rosin. With Spider Tack, while his velocity dipped to 75 m.p.h., his spin rate jumped 28 percent to 1,839 RPMs. He wondered aloud about using it in a game.

“Keep that drug away from him,” joked his father, Tony.

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A number of pitchers have expressed understanding for MLB's rationale in cracking down on foreign substances. But, many are frustrated that the league forced many pitchers to redefine the feel of baseballs in their hands in the middle of the season.

Matt Barnes is checked for foreign substances.
Matt Barnes (right, waiting with Christian Vázquez as an umpire checks Barnes’s equipment earlier this week) acknowledges that pitchers have been bending the rules, but questioned the timing of MLB’s decision to crack down. (Matthew J. Lee/Globe Staff)

“The rule in the book is the rule in the book,” said Red Sox reliever Matt Barnes. “Nobody has decided to enforce that rule for 40 years. It’s probably gotten a little carried away. I’ll admit that. There’s stuff in the game that doesn’t belong in the game. But the timing of it, to me, is the biggest issue.

“Doing it in the middle of a season just, to me, didn’t seem like the right answer. But I don’t know that there is one.”

But the midseason change created three distinct periods of data:

  • Opening Day through June 3 (the day MLB informed owners it would crack down on foreign substances): The baseline
  • June 4 through June 20: The transition period, as some pitchers began to adapt
  • June 21 through the All-Star break: Full enforcement and presumably full (or near-full) compliance

There are caveats: Warmer summer weather typically leads to improved offense, and strikeout rates generally dip to some extent in the middle of the season. But there is still clear evidence of change in how pitches are traveling to the plate and how hitters are reacting to them.

Since June 21, four-seamer spin rates across the league have fallen below 2015 levels. The pitch has yielded a .262 average (up from .249 through June 3) and .467 slugging mark (up from .442). Batters have swung and missed at 10.4 percent of four-seam fastballs, down from 11.0 percent through June 3.

Trend reversed?

Four-seam fastball statistics from MLB’s Statcast data, tracked since 2015

Inside the game, players have discussed how fastballs at the top of the zone have produced fewer swings and misses, the increased prevalence of hanging breaking balls compared to those that nosedive out of the strike zone, the rising use of two-seam fastballs – an offering where pitchers try to diminish spin in order to create sink – instead of high-spin four-seamers.

Multiple major league sources said they’ve seen pitchers lose up to 2 inches of spin-based vertical movement on four-seamers, or roughly two-thirds the width of a baseball. That can be the difference between a foul ball or swing and miss.

“The whole league has seen a difference,” said Martinez. “It’s amazing.”

Which pitchers are affected?

Four-seam fastball statistics from MLB’s Statcast data for 197 pitchers who threw at least 50 four-seam fastballs both prior to the June 3 decision to increase enforcement of Rule 3.01 -- the prohibition of foreign substances -- and since June 21, when umpires began routine checks of pitchers, show a number of pitchers with sizable drops in their spin rates. Click on dotted lines for detailed information on individual pitchers’ four-seam fastballs.

On a small screen device? Try rotating your phone sideways. 🔄
KEY: Before June 3
Pitcher's Name
After June 21
Showing 197 players
. (.)

. (.)

Change in average spin rate:
Change in average velocity:
Through 6/3
Avg. spin rate (RPM)
Avg. velocity (MPH)
Fastball thrown (Percent)
Swing and miss % (Counts)
Batting average
Slugging percentage

Red Sox starter Garrett Richards has seen his spin rate drop from 2,586 RPMs — in the top 5 percent of MLB pitchers — to 2,328 RPMs, a mark that places him around the top 25 percent.

Among the 197 pitchers who threw at least 50 four-seam fastballs both through June 3 and after June 21, Richards is one of 16 whose spin rate on the pitch has dropped by at least 200 RPMs. The biggest drop was by A's reliever Burch Smith, who went from 2,521 RPMs to 2,044 RPMs -- a decline of 477 RPMs.

A self-described user of sunscreen and rosin, Richards noted the difficulty of gripping and controlling not just his fastball but also his curve (he’s had to throw it slower to land it in the strike zone) and slider (missing fewer bats).

“I’ve had to reinvent a lot of things,” said Richards. “I would like to think I’ve been in the league this long, and I’m not here because I used rosin and sunscreen. I’m here because I’m a good pitcher. Just like me, a lot of other guys are going to figure out a way to be successful. It’s either adapt or die at this point.”

For now, Richards is among the majority of pitchers trying to stay on the “adapt” side of that line. Of the 197 pitchers who have thrown at least 50 four-seam fastballs both through June 3 and after June 20, 155 (79 percent) had seen spin rate declines, including 62 (31 percent) who had seen drops of at least 100 RPMs.

Not everyone will succeed in the undertaking. And there’s a good chance that some pitchers will skirt the rules and test the reach of MLB’s enforcement – particularly when it comes to the “jaywalking” substances of sunscreen and/or pine tar. Or perhaps, over time, the league will come up with a different solution – something in line with the ball used in Japan, which is manufactured to create tack without need of mud or other foreign substances.

But for now, MLB is trying to feel its way out of a years-long, sticky predicament.

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The Boston Globe
  • Reporter: Alex Speier
  • Editor: Katie McInerney
  • Digital storytelling, design, and development: Daigo Fujiwara
  • Video and Photo: Christiana Botic
  • Deputy director of photography: Kim Chapin
  • Copy editor: Robert Fedas
  • Quality assurance: Chelsey Johnson