If you haven’t yet read Bradford William Davis’ reporting on MLB’s usage of two different baseballs during the 2021 season, you’ll want to do so now. It’s essential reading. Davis, along with Dr. Meredith Wills’ research, showed clear cut evidence of two different balls being used in 2021. The league admitted as such, but blamed it on COVID-19.
The two different balls had different specifications and thus resulted in different performance outcomes. The league didn’t inform anyone about this, players included, though the players may have had a hunch something was awry. The original plan was to introduce a single and more consistent ball in 2021. Instead, balls from prior year specifications were circulated. There’s already plenty of speculation about how the league could have done this — I have a Yankees-related theory to present, too — but first, some hypotheses about how the balls were mixed in, straight from the report:
While the league blames COVID-19 for the dual-ball season and says it won’t happen again, some of the players reached by Insider entertained more conspiratorial hypotheses. For example: What if MLB sent a disproportionate number of either ball to a specific park or for a specific set of games, putting its thumb on the scale to create incentivized to introduce two baseballs” to try to produce higher- or lower-scoring games.
The National League pitcher who replicated Wills’ study believes MLB “is more or less incentivized to introduce two baseballs” to try to produce higher- or lower-scoring games.
“You know, send a bouncier baseball, lighter baseball — whichever flies more — to a primetime series,” he told me, listing off marquee matchups like Yankees-Red Sox and Mets-Phillies. “Then,” he suggested, send more dead baseballs to “Texas versus Seattle. Or, you know, Detroit versus Kansas City. No one’s going to bat an eye.”
On the other hand, he speculates, the league could flip that approach around and send high-octane balls to low-profile games and “produce more offense,” which might “put more seats in the stands. Just continue to bring up fan engagement.”
Again, these are merely unproven hypotheses. But they sure are interesting, no? Here’s my theory: MLB consistently supplied the new balls to games played at Yankee Stadium. In other words: the baseball that doesn’t travel as far was used exclusively in the Bronx, whereas the Yankees played with a mix of the two elsewhere. Here’s some data I was able to pull via Baseball Savant:
