MLB reportedly used two different baseballs last season

Major League Baseball reportedly used two different baseballs last season and players claim they had no idea, according to Bradford William Davis of Business Insider.

Dr. Meredith Wills — a physicist who specializes in sports — dissected and measured a number of baseballs used during the 2021 MLB season. Wills found some of the balls had lighter cores, which MLB promised to use during the 2021 season to curb offense. Others were heavier, and had the same properties as balls used in previous seasons, when the league's home-run rate exploded.

MLB's ball issues date back multiple seasons. The league acquired Rawlings — the company that supplies MLB with baseballs — in 2018. The following season, the home-run rate surged to an all-time high. A record 6,776 home runs were hit during the 2019 season. MLB admitted the 2019 batch of balls were made differently, but said the ball was not intentionally juiced.

Prior to the start of the 2021 season, MLB announced it would deaden the ball in an attempt to cut down on extreme home-run rates. The new ball was going to have a lighter core, which prevented it from traveling as far. Wills found those balls — which weighed 124 to 125 grams — were used last season. Wills also found balls that weighed around 127 grams, a figure consistent with the old ball, were used in 2021.

MLB admits two different balls were used in 2021

MLB confirmed two different balls were used during the 2021 season, but claimed it was due to COVID-19 causing production delays, according to Business Insider.

"Every baseball used in a 2021 MLB game, without exception, met existing specifications and performed as expected," the league said. But after approving the shift to the new "re-centered" ball for 2021, it said, COVID-19 forced Rawlings to backtrack and use older balls to cover for production delays. "Rawlings manufactures Major League balls on a rolling basis at its factory in Costa Rica," it said. "Generally, balls are produced 6-12 months prior to being used in a game. Because Rawlings was forced to reduce capacity at its manufacturing facility due to the COVID-19 pandemic, the supply of re-centered baseballs was not sufficient to cover the entirety of the 2021 season. To address this issue, Rawlings incorporated excess inventory into its shipments to Clubs to provide a full complement of baseballs for the 2021 season."

Wills' research doesn't support MLB's statement. Each MLB ball contains a batch code that lets a person know the date the ball was manufactured. Wills said those batch codes showed the ball fluctuated multiple times since 2019. MLB reportedly used the new, lighter version of the ball last October. It then reportedly switched back to the old ball in January, and continued to use that ball as recently as August, according to the batch codes.

MLB said it informed the MLBPA it would utilize two different balls in 2021. If the union knew about the change, the players didn't hear about it. Business Insider talked to 10 players for its story. None of them knew two different balls were being used in 2021.

The impact of MLB using different balls in 2021

It's tough to quantify the impact of MLB using two different balls in 2021, but the implications are significant. Can MLB ensure teams were supplied the same number of new and old balls? How did that impact statistics for each team? If one team received a larger percentage of new balls than most teams, does that explain why players on that team experienced offensive declines? Will a player from that team lose out on millions on the free-agent market because of MLB's tactics? Why in the world did MLB think this was a good or acceptable idea? These are all valid questions.

There's also the issue of gambling. MLB has embraced in-game wagering in recent years, and not being transparent about the baseballs could have a massive impact from a gambling perspective. How can bettors trust the league if it is using two different balls? To what lengths will people try to get inside information on which balls are being used in which games? It opens up some extremely dirty possibilities in a game that already has noteworthy gambling scandals.

MLB baseballs bunched together.
MLB reportedly used two different baseballs last season. (Photo by Kevork Djansezian/Getty Images)