Here's very interesting research from Art DeVany claiming that roids cannot explain the seeming surge in home run hitting. If you still have an open mind about these issues, pls read it (I'm not saying it's conclusive, just that it's worth learning more ab out it (hat tip MR).

I take up the matter of steroids more directly and also such possible influences as "hotter" baseballs, altered ball parks, smaller strike zone and find them all to be lacking. They do not stand up to verifiable tests or statistics. And they shouldn't because no explanation is required. There has been no increase in MLB home run hitting. Three home run hitting geniuses appeared in a brief time span and will soon be gone. Enjoy them and don't look for explanations when none are required. The law of home runs and extreme human accomplishment that I develop tell us that we never know when this kind of genius will appear, only that it will be rare and intermittent.

RTWT. That's an order.