Major League Baseball is in the middle of its first work stoppage since the 1994-95 players' strike. The collective bargaining agreement expired at 11:59 p.m. ET on Dec. 1, and almost immediately upon its expiration, the owners locked out the players. It's unclear when the owners' lockout will end, but until it does, hot stove activity is halted.

Just prior to the lockout, Bradford William Davis of Business Insider reported MLB used two different baseballs during the 2021 season. The league told teams it would use a lighter ball in an effort to reduce home runs this year. In previous years the league used a heavier baseball, leading to the increase in home runs. Both balls were within specification ranges, it should be noted, but small changes even within those ranges can lead to a big difference in performance.

Dr. Meredith Wills, an astrophysicist, has studied MLB baseballs the last few years and found both the lighter (2021) and heavier (pre-2021) baseballs were used this past season. MLB does not deny that. The league says manufacturing shortages related to the COVID-19 pandemic forced Rawlings to use leftover balls to meet demand this season. Here is MLB's statement:

"Rawlings manufactures Major League balls on a rolling basis at its factory in Costa Rica. 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."  

Each baseball is marked with a batch code indicating when it was manufactured. Wills found Rawlings manufactured both the lighter and heavier baseballs since late 2019. The lighter ball was produced from Oct. 2019 to Jan. 2020, the heavier ball from Jan. 2020 to Oct. 2020, the lighter ball from Oct. 2020 to Jan. 2021, and the heavier ball since. 

The batch codes tell us Rawlings, which is owned by MLB, did not simply fill the gaps this past season with leftover heavy baseballs manufactured prior to 2021. They also manufactured the heavier baseball in 2021. MLB says it informed the MLBPA about the change in baseballs, though several players cited in the Business Insider report are skeptical.

"I'm not sure what we were told, but I'd assume it was nothing. If the balls meet standards, then they would have no reason to tell us anything," said lefty reliever Andrew Miller, a member of the MLBPA's executive subcommittee. "... There's a fair amount of distrust between players in the league on certain topics, and this is one of them."

Having to use two different baseballs because of supply shortages created by the pandemic would be understandable, though the batch codes tell us both the lighter and heavier baseball were manufactured in 2021, raising questions. Here are four questions MLB should answer to help restore confidence in the product it is selling.


1. Why were two different baseballs used?

We know the official reason: COVID-19 created supply chain issues and Rawlings filled the gaps with leftover inventory. The batch codes tell us that's not really the case though. They tell us the heavier homer-happy ball was manufactured this year and used in big-league games this past season. So what's the real reason?

Was MLB not happy with the performance of the lighter baseball? Did an early season decline in home runs and offense spook the league and create concerns about the game's entertainment value, leading to a return to the heavier ball? Did someone at Rawlings misread the specifications and this is all one big misunderstanding? Something else entirely?