Major League Baseball finally has an explanation for the increase in home runs in 2019, and it's not juiced balls. According to a study commissioned by MLB, the seams on the baseballs are smaller and create less drag. Via ESPN:
"Decreases in air resistance spurred by inconsistent seam height on the baseball as well as "changes in player behavior" that produced different launch angles and exit velocities led to the dramatic increase in home runs during the 2019 season, according to a preliminary report released Wednesday by Major League Baseball. The surge to 6,776 home runs during the regular season -- nearly 11% higher than the previous record set in 2017 -- was accompanied by a decrease in postseason home runs due to a greater drag coefficient, which measures the resistance a moving object faces, according to the report."
So the baseballs are different. And players have changed their behavior to try and hit more home runs, I guess. The study doesn't mention it, but another factor in the total increase is Pete Alonso hitting the big leagues.
As stated by the study, there were 6,776 home runs this season, nearly a 11% increase from the previous record which was set all the way back in 2017.
The professors who did the study had a couple suggestions for MLB. First, keep better track of when the baseball batches were produced. Also, add systems to track atmospheric conditions to ball parks, and humidors to store the baseballs. Just like the good old days.