When people talk about steroids, they tend to talk about pictures like those below. Maybe they don’t use an actual picture, but the point is clear: the rate at which an extreme achievement—like home runs—has changed recently. And that change coincides with a possible increase in steroid use by players.
Because the shift in the 1990s was so dramatic, it’s hard not to wonder what happened. There is no denying that home run balls are flying out of the park more than they used to, which makes it hard to know why steroid skeptics, such as myself, do not acknowledge steroids to be the cause. Yes, Juiced and Game of Shadows tell us that steroids were rampant in the locker rooms of MLB teams during the home run boom. I really can’t argue with the fact that some players may have taken steroids. As to how much and what effect they have had on hitting power I still don’t know. It’s going to take more than accusations from Ken Caminiti, Jose Conseco, and anonymous sources to convince me of player guilt. Regardless of whether or not players used or not, I’m still not convinced that steroids, or any other PEDs, have much to do with the increase in offense. Here are some reasons not to blame the surge on steroids.
Steroids ought to impact both sides of the ball. If there are benefits, both pitchers and hitters will reap them. Recent testing has busted both pitchers and hitters. It is possible that batters benefit more than pitchers, though. So, this reason is not all that powerful, although I would like to see better arguments for the asymmetric effects of steroids on hitters and pitchers.
Also, the introduction of homer-friendly ballparks may have facilitated the home run surge, but it’s not enough. The balls are still flying out of the big places too.
Expansion is the explanation that gets little attention, yet I believe it is the most important factor for the power surge. The rise in home runs coincides with the expansion of the leagues in 1993 and 1998, which has increased the league by more than 100 players a year—a minimum of four 25-man rosters.
The late evolutionary biologist Stephen Jay Gould put forth a novel theory of extreme achievements competitive environments. His idea was that as the variance of the quality of participants shrinks, opportunities for great performances diminish. Being an avid baseball fan, Gould used baseball as his example. He argued that because MLB was being populated by better baseball players, great achievements, such as hitting .400, were decreasing. You see, very good players dominate very bad players, and as the very bad disappear from the game, the very good can no longer rack up good performances against them. Expansion has the effect of letting in the riff-raff for baseball’s elite to exploit. And we can see that as evidence of the inferior pitching entered the leagues that pitchers began to hit more batters. As the graph above shows—did I forget to mention it was a digram of the hit batter rate, not home run rate, over time?—the current era of baseball could just as easily be referred to as the hit batter era rather than the home run era. And most certainly, no one believes steroids cause pitchers to hit more batters—well, maybe it’s roid rage, but I don’t buy that.
Below is a graph of the hit batter and home run rates since 1960. They track together somewhat, but more importantly, they both shoot up in the 1990s, which is what Gould’s theory predicts.
Furthermore, we can examine Gould’s hypothesis by looking at the talent distribution of hitters and pitchers over time. The graph below maps the coefficient of variation (standard deviation/mean) of batter OPS and pitcher ERA by decade relative to the 1920-2005 average.
The higher the bar, the greater the distribution of talent and the greater the opportunity for great players to dominate poor players. It’s clear that the distribution of pitchers has been rising over the span that both home runs and hit batters have increased. The direction of this effect is exactly what we would predict, and the change is as dramatic as the change in home runs and hit batters.
Most certainly, this does not mean that steroids have not influenced the game. I just think it’s incorrect that there are no other plausible explanations for the changes in performance. Personally, I don’t think steroids have had that much of an effect, even if players have been taking them, but that is just my opinion. Furthermore, I believe Art De Vany is right.
Further Addendum: My follow-up post.