The next question in the three-year HR total issue set is: how does this data distribute itself by age range? A lot of discussion has occurred regarding the effect of steroids on late-career home run hitting...are we going to find a truckload of evidence when we look at three-year HR hitting totals in the associated time range?
Well, hell, let's just look at the chart at right, which shows the percentage fluctuation of 100+ HR achievers for the three-year periods beginning with 1989-91 and concluding with 2011-13.
Last time, we saw the spike in the late 90s when lots of people began to have 100+ HR totals over these overlapping three-year time frames.
Does this spike look ultra-suspicious for older hitters in this time frame?
The big jump in the late 90s period occurs in the 30-34 age range; the percentage of 100+ HR seasons in this group doubles from 1990 to 1997. It stays high right up to the point where the initial testing program comes into play, drops quickly and precipitously, then stages a bit of a rally over the next seven years.
The oldster range (35+) has its peak pretty much in the pattern built around Barry Bonds' ascendancy to the top of the three-year HR charts.
56% of the 100+ HR three-year player seasons from 1989 to 2013 came from players in what we call the "prime years" (age 25-29). Our chart at left shows that 60% of the hitters who placed #1 on those yearly three-year lists (if that makes sense...) were in those "prime years" when they topped the list.
And, as you can see, players in their prime (often in the extreme rightward portion of that prime) have been the three-year HR leader for the last nine consecutive years. Odds are astronomically high that this trend will hold for a tenth straight time in 2012-14.