In 2017, analysts began asking questions about the rise in home runs across baseball. Two studies were published -- one by Ben Lindbergh and Mitchell Lichtman for The Ringer, and another by Rob Arthur for FiveThirtyEight -- with each concluding that baseballs seem to have been altered at some point around the middle of the 2015 season.
Commissioner Rob Manfred was disingenuous speaking about the issue, releasing a statement in July 2017 and then speaking about it to the press during the postseason in October that year. Manfred reiterated that the baseball wasn’t changed, then disingenuously claimed players, fans, and analysts were being distracted by Game 2 of the World Series, which saw the Astros and Dodgers combine to hit eight home runs. Then-Astros pitcher Dallas Keuchel said the next day, “Obviously, the balls are juiced. I think they’re juiced 100 percent.” Keuchel joined fellow pitchers Justin Verlander, David Price, Brad Ziegler, Jerry Blevins, and Chris Archer among those to have spoken publicly about feeling a difference with the baseball.
MLB commissioned its own study -- published on May 24, 2018 -- on the rise of homers across the league. The executive summary concluded that the rise in home runs is attributable to “a decrease in the ball’s drag properties, which cause it to carry further than previously, given the same set of initial conditions—exit velocity, launch and spray angle, and spin.” Manfred acknowledged the study, saying, “I thank the committee for all of its hard work on this important issue. Based on the results of their study, I am accepting their recommendations immediately and look forward to their continued guidance in this area.”
Shortly after MLB published its study Dr. Meredith Wills performed her own research for The Athletic. She took apart and examined 26 baseballs, 12 from the 2014 season and 14 from the 2016-17 seasons. Wills found that the only statistically significant difference between her two samples was lace thickness. The 2016-17 baseballs’ laces were nine percent thicker. In a follow-up piece for The Athletic in September last year, Wills performed more research. This time, her two samples of baseballs were 20 from the 2010-14 seasons and 12 from April and May of 2018. She found that the baseballs in her 2018 sample were smaller in diameter near the seams. Wills wrote, “These findings suggest that balls made after 2015 have less bulging at the seams, meaning they are more spherically symmetric, and thus have lower drag.”
On Wednesday, Manfred spoke at the SportTechie State of the Industry conference. Per Eric Fisher of the SportsBusiness Journal, Manfred said that the recent rise in home runs has to do with non-ball factors more so than any change to the makeup of the baseball. He cited training, analytics, and coaching as reasons for the surge in dingers. It is interesting that Manfred continues to go against well-sourced evidence on the matter. It is also interesting that the commissioner is contradicting the findings of his own league’s study.
I don’t know what the end-game is for Manfred here. Being publicly disingenuous on the topic will only draw more attention to it. The makeup of the baseball very reasonably could have been altered inadvertently by the manufacturer. They are ultimately put together by hand, which makes them more prone to non-conformity. No one is accusing Major League Baseball of a vast conspiracy to change the baseballs to boost home run rates in an effort to boost interest. Manfred’s constant defensiveness on the topic, however, isn’t doing him or the league any favors.