Major League Baseball used at least two types of balls again this year, and evidence points to a third

Well on his way to his second World Series title, Houston Astros ace Justin Verlander shouldn't have had any complaints about his dominant, storybook season. And yet on a sunny June day in The Bronx, the 39-year-old three-time Cy Young winner knew something was off.

Before warming up with his team for a hotly anticipated match against the New York Yankees, Verlander made a point of confronting a Major League Baseball official on the field. With a wry grin that belied a long-simmering frustration he and many other players have felt, he ambled up to the official and asked within earshot of a reporter: "When are you gonna fix the fuckin' baseballs?"

The baseballs have been a source of controversy in MLB for years. Back in 2017, Verlander was one of several players and coaches that noticed the balls used at the World Series were slicker than normal. And last year, Insider reported that there were two distinct types of baseballs in circulation during the 2021 season, something the league had not disclosed. One ball had a center weight roughly two-and-a-half grams heavier than the other, making it carry further off the crack of the bat.

"MLB has a very big problem with the baseballs, and they're bad," Chris Bassitt, a pitcher for the New York Mets, said in a televised rant on SNY after an April start against the Cardinals. "Everyone knows it. Every pitcher in the league knows it. They're bad."

"[MLB] doesn't give a damn about it," he said. "We've told them our problems with [the baseballs]. They don't care."

When asked what made them so bad, Bassitt said: "They're all different. The first inning they're decent; the third inning they're bad; the fourth inning they're OK; the fifth inning they're bad… there's no common ground with the balls."

At a press conference before the 2022 All-Star Game in July, Rob Manfred, the commissioner of MLB, acknowledged that the league had used two baseballs the previous year, as Insider had reported. He chalked the ball variance up to a COVID-era manufacturing issue at the Rawlings plant in Turrialba, Costa Rica: The league had deliberately switched to a new, lighter, deader ball, but pandemic closures and supply-chain issues meant that it needed to dip into a reserve stock of the older, heavier, livelier balls for some 2021 games. The league claimed it distributed the two balls randomly for use in games.

But, Manfred promised from the podium, that was all over: "Every baseball that's in use in '22 was produced under the new manufacturing process" – meaning the deader ball – "and in fact, the process has resulted in a more consistent baseball."

But according to a new analysis of more than 200 balls used in games during the 2022 season that Meredith Wills, a Society for American Baseball Research award-winning astrophysicist, conducted, that's not true. Major League Baseball did not settle into using a single, more consistent ball last season, Wills' research suggests: the league used three.

By the time Manfred made that statement in July, Wills had already found evidence that at least a handful of those older, livelier, "juiced" balls — the ones that the "new manufacturing process" purportedly replaced — were still in circulation. Though these juiced balls are from 2021 or earlier, according to manufacturing markings, they were in use in 2022; Insider obtained two of them from a June 5 Yankees match against the Tigers.

Over the next few months, Wills and Insider — with whom Wills exclusively shared her research — worked together to collect game balls for her to painstakingly deconstruct, weigh, and analyze. What she found was striking: In addition to that small number of older juiced balls and the newer dead balls, Wills found evidence that a third ball was being used at stadiums across the majors.

According to Wills' data, MLB deployed this third baseball alongside the dead ball in 2022, with production starting as early as January – six months before Manfred promised a one-ball season. This new third ball's weight centers somewhere between the juiced ball the league phased out last season and the newly announced dead ball: It is, on average, about one-and-a-half grams lighter than the juiced ball and one gram heavier than the dead ball. According to the league's own research, a heavier ball tends to have more pop off the bat, meaning the third ball would likely travel farther than a dead ball hit with equal force.

While Insider accumulated 204 baseballs from 22 big league parks in 2022 — more than Wills has obtained in any of her previous studies — MLB also made sure it wasn't easy. One player told Insider that one of Manfred's top lieutenants warned a players' union official not to let players send any balls to Wills for "third-party testing" and warned that the league could fire any non-union team employees who helped her research. Nonetheless, we amassed baseballs from sources around the league, and supplemented our sample by purchasing balls fans caught and from licensed vendors at ballparks.

It is worth noting that all the balls we obtained fell within the legal specifications in MLB's rulebook. But as Alan Nathan, a league-commissioned physicist, once said, "The specs on Major League baseballs, they almost don't deserve to be called specs… They're so loose that the range of performance from the top end to the bottom end is so different."

But perhaps even more interesting than the apparent existence of the third ball itself is where we tended to find it. Though the overwhelming majority of baseballs we obtained were dead, 36 of them fit the bill for what Wills dubbed the "Goldilocks ball:" not too heavy, not too light — but just right. Of those, we found most in one of three situations:

• Postseason games, including the World Series;

• The All-Star Game and Home Run Derby;

• Regular-season games that used balls with special commemorative stamps — such as a Texas Rangers 50th anniversary ball — on the outer leather.

The only Goldilocks balls we obtained from the regular season that did not have commemorative stamps were from Yankees games.

When presented with Wills' research, an MLB spokesperson said in a statement that "the conclusions of this research are wholly inaccurate and just plain wrong.

"The 2022 MLB season exclusively used a single ball utilizing the manufacturing process change announced prior to the 2021 season, and all baseballs were well within MLB's specifications," the statement read. "Multiple independent scientific experts have found no evidence of different ball designs. To the contrary, the data show the expected normal manufacturing variation of a handmade natural product."

Ball manufacturer Rawlings — which MLB purchased in 2018 alongside San Diego Padres owner Peter Seidler's private-equity firm — denied changes to the baseball. "This research has no basis in fact," the company said in a statement. "There was no '3rd ball' manufactured and the ball manufactured prior to the 2021 process change was fully phased out following the 2021 season. All balls produced for the 2022 season utilized the previously announced process change.

"While storage conditions during research can easily impact ball weight measurements, a one-gram difference in ball weight would be within normal process variation," the statement read. "We continue to produce the most consistent baseball in the world despite the variables associated with a handmade product of natural materials."

MLB's newest ball is slightly heavier than the older dead Ball

While lighter and less bouncy than the balls used before Rawlings switched up its manufacturing in 2021, the Goldilocks balls have a weight profile that makes them livelier and more batter-friendly than the dead balls that the league says it now uses exclusively.

Wills identified them by breaking the baseballs down into their composite parts. She found that the center weights — or the weight of the inner layers — for 31 balls were heavier by an average of one gram each from the dead ball. Meanwhile, the circumference and diameter of the ball remained unchanged, which indicates that Rawlings wound the yarn around the core tighter.

Tighter winding and a heavier core are factors expected to raise a ball's coefficient of restitution, or COR, defined as the ratio of the speed of the ball leaving the bat to the speed of the pitch coming in.

A one-gram difference in baseballs, while perhaps nearly imperceptible in one's hands, can be significant when played out in thousands of hits over the course of a season. When the Korea Baseball Organization, for instance, decided to deaden its ball in 2019, it did so by slightly increasing its size and adding a gram in weight; home runs dropped by a third. While a heavier ball would ordinarily be bouncier, the corresponding increase in diameter had a deadening effect.

In a February 2021 memo to team executives explaining changes to deaden the baseballs that season, MLB wrote that "the weight of the ball [was] slightly reduced" upon loosening the winding of the yarn, which "slightly decreases the COR" of the ball with an expected effect of reducing the ball flight — a 375-foot fly ball would be reduced by a foot or two with the new balls, the memo said.

Goldilocks balls were all manufactured together, in specific weeks

All of the balls we collected fell well within the 5- to 5 1/2-ounce range league rules permit, and being handmade products, there is nothing surprising about some weight variance from ball to ball. But the different weight groupings weren't simply randomly distributed: Wills found heavier balls were made in certain weeks, lighter balls made in other weeks, and Goldilocks balls made in still other weeks. By analyzing the manufacturing date, she identified five additional Goldilocks balls for which she didn't have weight data, bringing the total to 36.

We can know when each and every Major League baseball is made, down to the week it was produced in Rawlings' factory in Costa Rica, by examining and decoding six-letter batch codes printed on the inside of each ball's leather cover. This process of dating each ball is what led Wills to find that two different balls were in circulation in the 2021 season, which the league admitted when we asked them about it.

Even though the league acknowledged the dueling 2021 baseballs, it disputed another of Wills' findings — that the heavier, livelier balls that were in circulation in the 2021 season had been manufactured that year.

"The researcher is just plain — are not right," Manfred said when asked about Wills' data at that press conference before the July All-Star Game. "There were 2020 balls that were out there – I just said that, right? – so they would find some from the old process, some from the new. But once we switched to the new process, they were all produced under the new process."

But the ball, as they say, don't lie: Roughly a quarter of the 88 juiced balls that Wills has obtained over the last two seasons were manufactured in 2021, according to the batch codes.

Asked to explain how he knew Wills' research was incorrect, Manfred replied: "Honestly, I can't help you on that one."

In response to Insider's inquiries about the Goldilocks ball, MLB provided statements from two researchers who work for league-affiliated research labs, one from Washington State University and another from the University of Massachusetts Lowell. Both said they had studied 2022 baseballs and found no variation beyond what you would expect from a hand-made product.

"We have tested 5 batches of MLB balls taken throughout the 2022 season," wrote Dr. Lloyd Smith, the director of the Washington State University's Sports Science Laboratory. "The balls were temperature and humidity conditioned prior to testing. The average weight and standard deviation of these balls was consistent for a handmade product made from natural materials. The standard deviation of each batch was nearly identical, and the difference between batches was well below one standard deviation. I see no evidence from these data of a ball design change in 2022."

Patrick Drane, a mechanical engineer and assistant director of the University of Massachusetts Lowell Baseball Research Center, concurred: "I have reviewed the statements claiming the use of three differently constructed baseballs during the 2022 season. In that context, I reviewed all of the test data through our year-long study at the UMass Lowell Baseball Research Center of the 2022 MLB Regular Season baseballs. The UMass Lowell Baseball Research Center data which we collected do not substantiate the claim that different baseballs were produced for the 2022 Regular Season. The UMass Lowell Baseball Research Center data which we collected shows all of the 2022 MLB Regular Season baseballs to be compliant with the MLB specifications and having statistically normal distributions for both size and weight."

Reached by Insider, Drane told us that he had studied "well over 300" baseballs," but declined to say whether they were game balls and if so, where and when they had been used. He did concede that his data set differed from Wills' in one key way: None of them were postseason baseballs. (Roughly half of Insider's Goldilocks sample was sourced from playoff games.) Asked to provide his research data, he said he would need MLB's permission first. Smith did not respond to a request for comment.

While the league is eager to dismiss Wills' research, not everyone shares Manfred's opinion of her. Wills is a Harvard-educated scientist with a Ph.D. from Montana State University, and her work on baseballs has been featured in Sports Illustrated and The Athletic. No less a scientific luminary than Hayden Planetarium director Neil deGrasse Tyson vouches for her work: "I'm delighted to see this breadth of expertise applied to America's pastime by my astrophysics colleague Dr. Wills," wrote Tyson in an email to Insider. "She may be uniquely equipped to sift what is objectively true from what people want or think is true in the game of baseball."

The Goldilocks balls seemed to appear in predictable situations

Twenty of the baseballs we obtained featured a commemorative stamp on the outside leather that distinguishes them from the standard MLB covers — 2022 Home Run Derby balls, stamped World Series balls, or baseballs commemorating the 50th anniversary of the Texas Rangers' inaugural season, to name just three. Those balls were effectively made for a particular circumstance and would never be used outside those specific events or home parks. (The three Home Run Derby baseballs in our sample were unused replicas purchased by Insider directly from Rawlings and from a collectibles site. They bear the same internal batch-code markings as the other game balls made in Rawlings' Costa Rica facility.)

In the sample we accumulated, nearly all of our specialty-marked balls were Goldilocks, while the standard, MLB-stamped balls were almost always the dead ball.

There were, however, 20 exceptions — Goldilocks balls that bore no specialty markings on their covers. We found:

• Nine in the postseason across four playoff rounds;
• 11 obtained from Yankees games.

Finding these balls might, in any other year, seem unremarkable. But this season, Yankees slugger Aaron Judge was in the midst of an historic home run chase. On October 4, at the Rangers' Globe Life Field, Judge broke the American League record for home runs, with 62. He became the first player who hasn't been credibly connected to performance-enhancing drug use to surpass Roger Maris' 1961 milestone. Judge's offensive dominance helped him clinch the 2022 American League Most Valuable Player award.

Our sample is not random. We got balls from whatever sources were available to us, and we can't represent that any particular ball was sent for any particular reason to any particular game. We don't know whether Judge hit a Goldilocks ball on his way toward breaking the record. But we do know that the league keeps track of information that would permit it — if it wanted — to know which balls get used in each game. According to two sources familiar with MLB's ball shipment process, the league not only directs where its balls are sent, it also knows which boxes its game compliance monitors – league employees tasked with ensuring each team adheres to league rules – approve and use before each game starts.

An MLB source who asked not to be named to protect them from league discipline, but whose identity is known to Insider, said that before each game, the league's game compliance monitors "[record] the batch number" – in this case, a six-character label placed on each Rawlings box – "and the quantity of baseball[s]... used for that game." Then, the league source said, compliance monitors send an email to their supervisors with that information.

"We're doing our own diagnostic, like, in the game"

Sitting in every player's locker on Opening Day this year was a pair of Bose headphones — "Beats by Rob," as one player less-than-affectionately dubbed them — and a note. Coming off a 99-day lockout, Manfred used the opportunity to make a promise to work with players around the league.

"Along with our clubs, I'm committed to working together with all players to grow the sport," Manfred wrote. "I'm excited about the opportunities that lie ahead and by working together, I know we can bring the game to new heights."

Manfred also met with teams around the league to discuss potential rule changes. According to the players who spoke with Insider, these conversations regularly evolved into discussions about the consistency and quality of the baseball, from well-publicized issues with its grip to the multi-ball usage from 2021.

In one closed-door team meeting with Manfred, a player brought up an independent study from May that found a noticeable, "hitter-friendly" shift in the ball's expected distance even when controlling for climate's impact on ball flight, leading the analyst to suggest MLB was using something other than the dead ball.

The player recalled that Manfred responded to his citation of the study by not only allowing the possibility that older juiced balls were in use (which is precisely what Insider found), but that another ball was coming. "They knew they had to adjust balls to be more consistent cores instead of pushing boundaries both loaded and dead," the player wrote to Insider via text, summarizing Manfred's answer. "So mid-May there were finally no balls from 2021 so his reasoning was now only balls meant for this year are in games. Perhaps they have swayed back and forth too much."

If this was indeed a concession, it contradicted Manfred's public statements and private claims to other players. Players told Insider that in other meetings, Manfred insisted that any variation in a ball's performance did not come from systematic manufacturing changes, but typical variance from a handmade product, a claim he repeated to ESPN's Don Van Natta in a lengthy June interview.

The Yankees may be one of the few teams that did not meet with Manfred, according to pitcher and team union rep Jameson Taillon, who was still waiting for a meeting with the commissioner as late as October 2, the last Yankees home game of the regular season. Though he never got to speak with Manfred alongside his Yankees teammates, Taillon did recall one league official approaching him in the locker room during the second half of the season to see if the veteran pitcher had noticed "anything different about the baseballs" lately.

San Francisco Giants outfielder Austin Slater came across our 2021 story and wanted to get to the bottom of the baseball issues. But when he expressed a desire to collect balls to send to Wills for analysis, he received a stark warning from a top executive in the commissioner's office: Stand down. The warning, sent in the form of text messages that Insider reviewed, came via a players' union official who was relaying the league executive's displeasure.

According to the texts, the league executive told the union leader that "we would be glad to run any tests [Slater] wants on baseballs," touting the aforementioned labs at the University of Massachusetts Lowell and Washington State. The rep said the executive told him MLB wasn't "comfortable sending out game-used baseballs for third-party testing" because those balls are distorted by being "hit around [and] thrown around."

"Cutting that ball open," Slater said, repeating the executive's argument, "isn't the same as looking at a baseball out of the factory or humidor."

Wills said that some of the balls she collected came from ballparks equipped with humidors, and some didn't. In any event, she said, she conducted her research in humidity-controlled conditions. "The storage conditions during analysis were comparable to those of a humidor," she said, "roughly 70 degrees and 55 percent humidity, or a dew point of 54 degrees."

Slater said the MLB executive specifically mentioned that the league does not want any game balls going to Wills — and that the league could fire anyone linked to giving out baseballs.

The threat worked. Though players are protected by a powerful union from getting fired over taking home a baseball – something Slater, a member of the MLBPA's executive subcommittee understood – he was worried about non-union staff who retrieved a ball for him getting punished by the league. "I don't know how they got wind of what we were doing," Slater wrote to Wills. "But considering this I won't be sending any balls out. I don't want [any] of our guys getting in trouble with MLB."

The league did not dispute Slater's account, but denied that it ever threatened anyone's job. "As a policy, we do not participate in third party studies without clear visibility into research methodology, including storage conditions," a spokesman said in a statement. "The MLBPA agrees with this policy. The notion that any employee was threatened by MLB is entirely false." The MLBPA declined to comment.

Players continue to notice oddities or inconsistencies with the baseball's performance. "Sometimes you see the exit [velocity] and the launch angle and you put it together, and that should be going home run," said Los Angeles Dodgers ace Clayton Kershaw. "Like the guy hits it 105 miles per hour at a 30-degree launch angle. That's probably a home run everywhere. But sometimes, for whatever reason, the same guy hits it the same way and it's [an] out."

Minnesota Twins veteran Chris Archer was more emphatic about how suspicious teams are about the problem. "The coaches are aware [about how we pick baseballs]," said Archer, sharing how pitchers frequently toss baseballs that they feel are too hard in their hands, fearing that those might be more juiced. "We're doing our own diagnostic, like, in the game. [Asking ourselves], 'What did I use?'"

Other players felt the changes were subtle but nonetheless expressed concern for the precedent of using multiple baseballs and the lack of transparency from the league.

"If a baseball is random, the way MLB described it, you would see a rainbow of flavors, of weights on baseballs," said Max Scherzer, the New York Mets' fireballer who took a leading role in negotiating the current CBA. "But if you see two distinct weights being manufactured, then it's only rational to assume that you know how to make the two weights. And if you know how to make the two weights, then that's intentional, not random."

Referring to both last year's report and the new trove of data, Scherzer added: "When you have numerical data suggesting [what] you have, that finger does get pointed at MLB. And that's completely fair for the players to ask that question. We don't feel like we're being told the whole answer."

"In the [NFL], there was Deflategate. It happened one time, and people were punished," said Philadelphia Phillies outfielder Nick Castellanos. "Here, we use multiple balls, and nothing happens."

Front office executives, like players, appear left in the dark about MLB's latest change to the baseball or use of multiples. Insider spoke to nine top-ranked baseball operations executives from separate teams, all of whom said the league did not inform them or their respective teams about a new ball being introduced.

Manfred himself knows how minute changes to the ball can impact the game, and even make history.

When Judge hit his milestone, Manfred described it as "a monumental achievement" that will "stand the test of time." But he also said he deferred to fans over statistics when interpreting Aaron Judge's 62 homers over Bonds' 73, conceding that the range in ball performance can — like steroids — impact statistical outcomes.

"I think that over the history of the game there have been different eras, the ball performed differently, the equipment was different," he told ESPN in October, shortly after Judge clubbed number 62. "I think the best way to handle it is to let fans make their own judgment as to what records are most significant to them."

After the All-Star Game press conference in July, I approached Manfred in a second attempt to get a response to Insider's reporting. He referred back to his answers from the dais, arguing that "we tried to be transparent" about what MLB was and was not doing about the baseballs.

"But ultimately," Manfred reasoned, "this is yesterday's news."

Correction: December 7, 2022 — An earlier version of this story inaccurately referred to Dr. Lloyd Smith's affiliation in one instance. He is the director of Washington State University's Sports Science Laboratory, not a researcher at the University of Washington.