After looking at the future of the 3000 hit club last month, I began wanting to try my method out with other milestones. The natural next step was the other big milestone for hitters, 500 home runs. Would there be any difference in how early we could predict who would make each club? The Hall of Fame induction ceremony seemed like as good an excuse as any to look at a milestone like this (even if it was three 3000 strikeout guys and a 3000 hit guy getting inducted this year).
A quick refresher on the methodology: first, I went through the 26 members of the 500 home run club and looked at how many home runs they had at each age. I sorted them by totals, then split the club into the upper half and lower half. Next, I looked at how many hitters throughout history had more home runs than the lower half at the same age. Then, I just took a simple percentage of (upper half of the club) divided by (total number of retired hitters who had more homers than the lower half of the club at the same age). I expanded on what I did for the 3000 hit article, though; rather than just do the halfway point, the lowest, and the second lowest, I threw in the quartiles (the halfway marks of the halves). That way, I could estimate the odds for players above 25% and 75% of the 500 homer club.
In each grouping, I took out the players in the quartile above, so that I'm not double counting, say, the guys in the top quartile as in the second quartile as well even though they are above the mark needed to be in that group. This is to give a more accurate sense of how likely players in that quartile specifically are to reach the 500 mark; using the player with the most homers at that age to predict someone just over the halfway point seemed a little silly. This leads to a little fluctuation in the results (sometimes, the second quartile will have fewer players eventually making 500 home runs than the third quartile, for instance), but usually, the variations aren’t too significant.
These odds aren’t going to be super-precise for a variety of reasons; this is a very rough model, the game has evolved dramatically since when some of these players played, I’m not really weighting each player by where they are individually, and so on. However, I think it gives us a pretty good rough idea; it may be off, but it gives us a tangible, easy to visualize predictor for something that’s normally pretty difficult to predict. As an aside, I’d caution against using the “Lowest” number as a hard guideline, since that player was almost always an outlier; sticking to the “Second Lowest” benchmark and above should be more indicative. So, with that in mind, which modern players are on pace for 500 home runs?