It has been a sad, sad season on the south side of Chicago. The White Sox entered the year with their usual high hopes and the fifth highest payroll in the major leagues this year. Optimism may have been unfounded, as even on paper the Sox looked like the fourth best team in baseball’s strongest division, but few could have foreseen the scale of the catastrophe. The Sox will spend the last month of the season trying to fight their way ahead of the wretched Kansas City Royals in an effort to stay out of last place, and they may well lose 90 games for the first time since 1989, when Ozzie Guillen was a 25-year-old shortstop, rather than an embattled manager.

One of the few consolations for disheartened Cub-haters will be Peoria native Jim Thome’s attempts to hit his 500th home run. Sitting on 493, Thome could well reach the mark this season, given his health; he hit seven longballs in July, and six or more in four different months last year. Even if he does become the 23rd man, and the third this season, to reach 500, the most interesting part of the story will be just how little it means.

For several years now, sportswriters and fans have been grousing that 500 was becoming a meaningless number, but there’s been little reason to think this true. Of the 23 men who have reached the mark, only three — Mark McGwire, Sammy Sosa, and Rafael Palmeiro — are considered by anyone to not be clearly deserving Hall of Famers. And even those who think that their numbers don’t warrant plaques in Cooperstown because they were inflated by a hitter-friendly era, and possibly by drugs, would admit that these three are, at absolute worst, qualified candidates.

Thome is something different. There’s no doubt he’s been a great hitter. His on base plus slugging percentage, adjusted for park and league effects, is 15th best among players with at least 5000 plate appearances since 1947, and 11th best among all first basemen ever. This is a heck of a credential, and Thome certainly has more going for him than one number. He was an integral part of the great Cleveland Indians teams of the 1990s, he has had several individual seasons worthy of serious MVP consideration, and unlike McGwire, Sosa, and Palmeiro, he’s not only never been tied to scandal in any way, but he’s been honored for his good deeds and held up as an example of what a clean athlete can do.

Still, I’m not convinced he’s worthy of the Hall of Fame, and given that he’s an injury-plagued 37-year-old, I can’t imagine that he’ll do much over the rest of his career to change my mind.

The first issue is playing time. Thome has had a reasonably long career, but he’s only played 150 or more games in four different seasons, while this year will be the fourth season since he became a full-time regular in 1995 in which he’s played fewer than 140 games. This counts, and it’s added up. Thome has had 8,303 plate appearances in his career; the only post-war first basemen in Cooperstown with fewer than 10,000 are Willie McCovey and Orlando Cepeda.

The second issue is defense and base-running. Thome’s reputation in these areas is far worse than the reality; he’s played nearly 150 more games at third base in his career than he has at designated hitter, and he’s only played at DH as much as he has because he was traded to a team with a very good first baseman two years ago. Still, I don’t think anyone would claim he’s been actively good at anything other than hitting, and this is meaningful in his case, because the playing time issue means his hitting hasn’t been as valuable as it seems.

The most important issue, though, is one on which people can and do differ, and it’s this: Thome might not even be one of the 10 best players at his own position in his own era. This depends on how you define his era, but Palmeiro, McGwire, Jeff Bagwell, Frank Thomas, and Albert Pujols are all better players, and reasonable cases could be made for Will Clark, John Olerud, Todd Helton, and perhaps Fred McGriff and Edgar Martinez as well. For that matter, Jason Giambi has been every bit as good a hitter as Thome and has an MVP award on his mantle. He’s been even less durable than Thome, and obviously has other issues, but most people wouldn’t even begin to think of him as a Hall of Fame candidate, and it’s hard to see any reason other than the number 500 that Thome should be considered one if he isn’t.

Countering this, one could argue that it’s not Thome’s fault that he plays in an era of great first basemen. Richie Ashburn, for instance, was the fourth best center fielder in baseball in his prime, in a league that had half as many teams as today. We don’t hold it against him that he was a peer of Willie Mays, Mickey Mantle, and Duke Snider. Why hold it against Thome that he had the misfortune to play at the same time as Bagwell and Pujols? This is the real question here, and it’s far trickier than the fake issue of 500 home runs supposedly becoming devalued. On the one hand, an era in which Jim Thome might not be one of the 10 best players at his own position is obviously one that’s simply stacked with an ungodly amount of talent. On the other, the conditions of the era, which so heavily favor walks-and-homers players who can’t do anything else, obviously make players with his skills more valuable than they would have been at almost any other point in history, and thus devalue his achievements. How much they devalue them is the question, and it’s one we’ll need time and perspective to answer.

Either way, none of this has any bearing on what Thome will do in September, which gives fans of a hopeless team a reason to come out to the park, and what he’ll do next year, which could be anything from missing the whole season to injury to hitting 50 home runs while leading the White Sox to their second world title in four years. I suspect the former is more likely than the latter, but if Thome proves to have another monster year left in him, it will just make things all the more complicated. It’s almost too bad for Hall voters that no one has baselessly accused the man of using drugs. That would make things so much easier.