Home Run Rates Down, But What's the Reason?

Some have noticed that the home run rate is down for the second year in a row. Does that tell us that Major League Baseball’s efforts to stop the use of performance enhancement drugs (PEDs) is having an effect?

Let’s look at the recent trend using home runs in the last three years. In the 2006 season, major league hitters hit 5,386 homers. They only hit 4,957 in 2007, a drop of 429 home runs. That is a big change. If you prorate 2008, we will have another drop of 500 or more.

However, we need to remember that the early season typically slows down the home run rate, primarily due to the colder weather. Past studies show that the warmer the temperature the more runs are scored and homers are hit.

Here are the homers per game in the last three years for games played before May 23:
2008 1.83
2007 1.88
2006 2.20

The drop in home runs this year is minimal thus far.

Let's look at recent Major League history. Here are the homers per game for a full season in the last 40 years:

2007   2.04
2006   2.22
2005   2.06
2004   2.25
2003   2.14

2002   2.09
2001   2.25
2000   2.34
1999   2.28
1998   2.08

1997   2.05
1996   2.19
1995   2.02
1994   2.07
1993   1.78

1992   1.44
1991   1.61
1990   1.58
1989   1.46
1988   1.51

1987   2.12
1986   1.81
1985   1.71
1984   1.55
1983   .157

1982   1.60
1981   1.28
1980   1.47
1979   1.64
1978   1.41

1977   1.73
1976   1.15
1975   1.40
1974   1.36
1973   1.60

1972   1.36
1971   1.48
1970   1.76
1969   1.60
1968   1.23

It's interesting to note that all the home run rates above two per game are in the so-called Steroid Era (1994 to 2007), except for 1987. This year we may be looking at the first sub-two season since 1993.

Nevertheless, since 1968, there have been several occasions where the home run rate dropped two years in a row. Our current trend of 2008 being a second consecutive drop in the home run rate is not that surprising. The last time we had drops in three consecutive years was the early '40s. If we see this drop continuing in 2009, then we might know something. For now, we need to sit tight.

Sources: Baseball Info Solutions and Baseball Encyclopedia. "Used with permission from John Dewan's Stat of the Week™