The home run epidemic continues unabated. This is neither good news nor bad. It simply is what's happening in the game right now. If you are freaked out about the number of long balls this season and were hoping that things might settle down over the second half, that's not what has happened. It has been the opposite.
The homer surge has only become more virulent during the month since the All-Star break. Teams are averaging nearly 1½ homers per game and are scoring five runs per contest during that span. The big league ERA since the festivities in Cleveland is 4.65. If that were the season's overall ERA, it would be the highest since 2008.
Lately, I've picked up on a number of pointed discussions in and out of the media, wondering which is more juiced: the ball or the players. While I can't say with any degree of certainty that a large population of players are not circumventing baseball's PED testing safeguards, or are imbued with some kind of new undetectable designer performance enhancer, I can say I don't really care one way or the other. It seems unlikely. But to suggest that such a thing accounts for the spike in homers we saw in 2017, which seemed to recede a bit last year but has surged back with a vengeance this season and -- coincidentally -- spread to Triple-A the very same season they started using MLB balls at that level, well, it seems like a pretty dense notion.
We've been over this again and again, but to me there are only three plausible explanations for the pattern and abruptness of these changes in home run rates: the ball, something to do with atmospheric/weather conditions and stylistic trends. (Obviously a fourth possibility would be some mix of the above.) The climate-related theory is at present hard to dig into because, as far as I know, there hasn't been an expansive study done on that. So let's put a pin in that concept for now.