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:
Now, it’s important to caveat that the data I pulled is from the entire season, meaning that it includes data before and after the foreign substance crackdown. Sticky stuff does impact drag, which can make for an inconsistent environment in the data I grabbed. Plus, weather plays a role, further complicating environments as no single day is the same as another. I obviously don’t have access to every single baseball used at Yankee Stadium, either.
Those notes aside, it’s still clear that there’s a big difference in performance at home vs. on the road for Yankees’ hitters. Any way you slice it — all contact qualities, Hard Hits, or Barrels — the Yankees hit the ball further on the road. And to get more granular, the data was very consistent broken down by launch angle:
Once above the 14 degree launch angle, balls consistently traveled further for the Bombers away from Yankee Stadium. Now, let’s do a similar check, this time with exit velocities:
Again, the data is consistent, especially as exit velocities enter the Hard Hit (95+ MPH EV) range.
Taking things one step further, let’s take a look at how individual players fared:
Yet again, away distance is king. Yes, there are two exceptions: Giancarlo Stanton and Gary Sánchez, but all others experienced a discrepancy.
Remember this chart from my season review of DJ LeMahieu?
Huh! I wonder what happened here?! Perhaps if the league didn’t funnel the new baseball to the Bronx, LeMahieu’s season looks a lot different. Grr…
There sure is a lot of data pointing to something strange that went on in the Bronx. Seems reasonable to think that the league would want to avoid sending the old ball to Yankee Stadium, right? Especially given its propensity to yield home runs. Had they mixed in the old ball (as they did elsewhere), there likely would have been more home runs (akin to prior years), and people would have wondered earlier about the “new” baseball not actually changing anything.
I’m curious to see if there’s evidence of this at other ballparks. Data from one team at its home ballpark vs. the road isn’t quite enough to prove a leaguewide conspiracy, though I feel it’s pretty safe to assume that the Yankees played with the new ball at home and a mix away. Whether my theory is accurate or not, the league’s mishandling of this situation has opened itself up for speculation just like what I’ve presented today.