We studied the home run trends over the last four seasons in our June 30th Stat of the Week and found a four-year low.  But we wondered if we were seeing the effect of the cold start of the season.  Now we know the full season results.

 

Year	HR/AB
2005	3.02%
2004	3.26%
2003	3.12%
2002	3.06%

 

Homer Runs per At Bat (HR/AB) remained at a four-year low, though still not that much lower. 

 

What about the percentage of runs scored by HR?

 

Year	Pct of Runs Scored by HR
2005	36.2%
2004	37.0%
2003	35.9%
2002	35.8%

 

Interestingly, it is the second highest of the period shown, though that might point to more emphasis on winning with power.

 

Maybe we need other gauges.  Slugging percentage might tell us something.

 

Year	Slugging
2005	0.419
2004	0.428
2003	0.422
2002	0.417

 

Not a four-year low, but close.

 

Another gauge is isolated power (slugging percentage minus batting average).

 

Year	Isolated Power
2005	0.154
2004	0.162
2003	0.158
2002	0.155

 

Another four-year low, though just barely.

 

If you already believe the new drug testing program is causing change, you found enough statistics here to confirm your opinion.  But the changes could easily be attributed to the normal random ups and downs (also called random flux) of statistics.  We need to check in after next season to review the trends again, especially with the rules getting even tougher.