Rafael Palmeiro finally passed the 500-home run milestone today in fromt of his hometown fans in Arlington. He is the second man, after Sammy Sosa, to pass the milestone this year. They soon may be joined by Fred McGriff (483). Ken Griffey Jr. (469) is also a longshot to reach 500 given that he is still recovering from an injury.

Some will say that the glut of home runs has caused the 500-homer explosion this season. Some will say that Palmeiro's presence on the selective list cheapens it somehow. Some will say that Palmeiro should be the first 500-dinger man kept out of the Hall once he retires. I've already debunked the watered-down 500-HR theory.

As for Palmeiro's enshrinement, keeping him out would be unprecedented. He will be a litmus test for future home-run hitters, just like Don Sutton was for pitchers. Sutton won 300 games but many felt that he was not a Hall-of-Fame type pitcher. Therefore, many criticized his induction feeling that the Hall was watered down enough with various Ross Youngses and Travis Jacksons. However, as Bill James argued, keeping a player out of the Hall who is clearly qualified is as bad as if not worse than letting underqualified players, such as Youngs and Jackson. If the Hall capriciously readjusts its de facto to prevent more modern players out, then it becomes a dying institution. Given that Palmeiro surpasses most of the established standards, according to James' criteria, keeping him out of the Hall is a dangerous proposition. (For the record, Palmeiro qualifies for three of the four James' tests: he falls short in the Black Ink test, but given that there are a great deal more players since expansion, very few modern players exceed the established crietrion.)

Palmeiro is probably the least likely 500-homer hitter that you can find. Though his current record streak of eight straight seasons with at least 38 home runs is often cited, Palmeiro did not collect more than 26 in a season until 1993 at the age of 28. He had only collected 95 homers in his 6+ previous seasons. That's the least by that age for any who hit 500. It should be pointed out that Palmeiro was always a very good hitter even in these early years: his OPS was between 21% and 55% better than the adjusted league average in every full season but one before his 28th birthday.

Here is a breakdown of the number of home runs hit by the members of the 500 HR club (plus Fred McGriff) at various stages of their careers (i.e., the season in which they were the given age for the bulk of the season):

Note that Palmeiro made up for his lack of home runs in his youth with a devotion to the stat in his old age. He ranks sixth all-time in home runs after turning 30.

If he matches his post-30 average of around 42 in 2003, he would rank 12th all-time (barring what Sosa does). That would put him firmly in Jimmie Foxx and Mickey Mantle territory. I don't know if he can keep it up at his age, but two such seasons (42 HRs) would put him seventh all-time right behind another first baseman by the name of McGwire. 600 home runs are not out of the question for Palmeiro.

Could he hit 600 and still be barred from the Coopertown. It seems too incredible to think.