An MLB-record 6,776 home runs were hit during the 2019 regular season, up from 5,585 in 2018, with many fly balls that had been fly outs in the past (or extra-base hits) instead sailing out of ballparks.
In addition to the baseballs during the 2019 regular season flying differently once they were hit was the fact that lower seams and a slicker surface hindered pitchers from being able to grip and/or control the baseball like they were used to.
Then came the 2019 postseason, when the balls were seemingly de-juiced.
So what happened?
Dr. Meredith Wills, an astrophysicist and contributor to The Athletic who spoke with SNY in March about what caused the 2019 regular season baseballs to be so different, wrote on Monday after testing samples of baseballs used in the 2019 postseason that some were from the 2019 regular season and others were from the 2018 regular season.
"Contrary to previous statements (from the league), testing showed that balls provided for 2019 postseason games were a mixture from the 2019 and 2018 regular seasons," Wills wrote. "Why would this be the case? A new theory has emerged - one that comes down not to "de-juicing," but to simple supply and demand."
While Wills hypothesizes that the reason MLB used balls from 2018 and 2019 is not nefarious -- that they were simply running out of inventory -- she also wondered why "MLB has continued to maintain that all 2019 postseason balls were taken from 2019 regular season stock."
Whatever happened to cause the difference in the postseason, Wills told SNY in late-March to not expect major changes from the 2019 regular season baseballs to the 2020 regular season baseballs if/when the season begins.
"In theory, they might still be producing them," Wills said. "Everything would have to run perfectly, including full quotas, no mistakes, and you'd be at least six months to get the total number just to be used by MLB. ... Based on that narrow window -- assuming they had a few months to take data from the previous season and then find a way to use it for the subsequent season. That means that really major changes just aren't possible."
While major changes aren't likely, Wills did point to one change that could help pitchers who had trouble gripping the baseballs last season.
"The slickness is the only one that I can think of that would be easy to change on a short enough time scale based on what was seen. ... I think that means that they'll end up with not as slick a texture," Wills explained.
And hopefully if/when the 2020 postseason rolls around, the league will have enough baseballs from its 2020 inventory to get through all the games without having to dip into old inventories.