A little, but the dip has been less than you might think.
First, let’s define when this Home-Run Era started. People generally place 1998 as the first year of this new Home-Run Era. That was the year of the historic race between the beloved Mark McGwire and Sammy Sosa. McGwire broke Roger Maris’ record that year (hitting 70 home runs) and Sosa also had a pretty good year (hitting 66 home runs).
A little time looking at the data suggests an earlier starting point. In the 1990s, the average number of home-runs per game first crossed the 1.00 home-runs per team per game (HR/TG) threshold in 1994. But 1994 and 1995 were strike shortened seasons, so we can bracket them for now.
However, 1996 is relevant: there were 1.09 HR/TG in Major League Baseball in 1996. That’s greater than the frequency of home-runs in 1998, 2002, or 2003, making 1996 a good candidate for the beginning of the Home Run Era.
For sake of reference, from 1990 to 1993, the frequency of home-runs ranged from .72 – .89. So, a rate of greater than 1.00 home-runs per game represents a significant increase over previous years. And over previous decades. In the 1950s, 1960s, 1970s, and 1980s combined there was one season (1987) when more than 1.00 home-runs were hit per team per game.
But using the 1.00 HR/TG standard to delimit the home-run era defies conventional wisdom, because the current belief is that MLB players are not hitting home-runs with the same frequency as they once did…because batters are now using fewer performance-enhancing drugs and are visibly smaller than they used to be. But last year, MLB players hit 1.02 home-runs per game. And in 2009, they hit 1.04.
We could just agree to say that we are still in the Home-Run Era. But that is intellectually uncomfortable because it suggests that either a) MLB’s drug-testing program – considered state of the art by most, and unnecessarily invasive by some – is ineffective in breaking the connection between more frequent home-runs and player use of steroids, or b) the players’ use of steroids provides a less comprehensive explanation for the rise in home runs than is widely thought. Plus, there’s this other problem: no one is hitting 60+ home-runs a season any more.
Let’s circle back to using home-run frequency to define the Home-Run (or Steroid) Era. Since 1998 is popularly considered the start of this era, let’s look at the home-run rate for that year – 1.04 HR/TG. That is pretty low by the standards of some of the years to come, but we can just use it as a quick baseline. With 1.04 HR/TG as our cut-off for inclusion in this era, the era stretches from 1996 through 2004, with a dip in 2005 (1.03) and a serious return in 2006 (1.11) before a few years of decline. That seems right. Except for this. The 2009 season (1.04) – post steroid testing – would have qualified, and last year (2012) came close – 1.02.
A more exacting standard would be 1.10 HR/TG, and 5 years in this era met that threshold. But they aren’t particularly well clumped together (meaning many years in the middle of this era don’t reach this threshold) and some banner years of the era would be excluded – like 1998.