This is going to be kind of a weird post, because it sets out to answer a question that’s very difficult to answer. Before we get to why, let’s get some basics out of the way.
In June, Jeff Sullivan over at Fangraphs wrote an article noting that something paused the “home run spike” that had been “blamed,” in large part, on “juiced” baseballs. That’s a lot of quotes for one sentence. You can read that article, and a lot more. In particular, there’s an article by Jim Albert here that has a particularly instructive chart.