The Effect of the Steroid Era on Major League Baseball Hitters: Did It Enhance Hitting?

Background: The “steroid era” in Major League Baseball (MLB) was a time when drug testing for performance enhancing drugs (PED) was not routinely performed. Purpose: To determine if there was a correlation between the steroid era and home runs, batting average, and isolated power (ISO) in MLB players. Methods: Home run, batting average, and ISO data from 1973 to 2012 was collected and analyzed. The data from the steroid era 1993-2002 was compared to the pre steroid eras 1973-1982, 1983-1992, and post steroid era 2003-2012. Results: There was no statistically significant increase in the number of home runs (HR) hit by the American League (AL), National League (NL) or overall in MLB. There was no statistically significant increase in the ISO or highest yearly single player HR total during the steroid era. There were significantly more players who hit 40 or more HR per season during 1993-2002 compared to each of the other time periods (p<0.002). Throughout all time periods, there was no significant change in batting average. Conclusion: There was a significant increase in players who hit more than 40 HR in a single season during the steroid era compared to before and after this time period.