Although I haven't seen any scientific evidence for juiced baseballs. And there have been some inquiries.
I've said elsewhere that I think that things happen in cycles. Remember in the 80s, when you pretty much had to steal 100 bases to lead the league?
It had only been done twice before that... Maury Wills with 104 in 1962, and Lou Brock with 118 in 1974.
Now you don't see it anymore. Were the baserunner's cleats juiced? ;^)