Last week, Baltimore’s Rafael Palmeiro nailed down his Hall of Fame bid with an opposite-field double in Seattle – the 3,000th hit of his career. Next on the list is 600 home runs, which he stands 34 short of as of today. Around the time he reaches number 600, he should also be well past 1900 RBI, which will place him in the Top 10 all time in that category and leave him in a group with only Hank Aaron and Willie Mays as players with at least 3000 hits and 600 homers.

But no matter what sort of record busting numbers he closes out his career with, Palmeiro, who turns 41 in September, will leave behind a number of unanswered questions. Among those questions should not be: “How can you be so good for so long and not get more recognition?” The answers to that question are simple.

First, Palmeiro is Latin, and Latin players generally have to play better than English-speaking players just to be recognized. For roughly 16 full seasons – from 1988 through 2003 – Palmeiro and Fred McGriff were neck-and-neck in nearly every key batting statistic; yet for most of that span, McGriff, not exactly Mr. Excitement, was far better known among average baseball fans and even earned himself a nickname (“Crime Dog”).

Second, Palmeiro had the misfortune to have most of his best seasons with the Texas Rangers, a team whose leading players – such as more bankable Latin stars like Ivan Rodriguez, Juan Gonzales, and Alex Rodriguez – usually overshadowed him.

Third, Palmeiro became a star in the early 1990s, when great hitting first basemen, most notably Mark McGwire and Frank Thomas, were plentiful. Fourth – and this is a very curious thing – Palmeiro, despite his now-legendary power numbers and remarkable durability, has never led his league in batting, home runs, or RBI.

Among the major questions he will inspire when he’s gone is whether greatness should be defined as peak performance or quality consistency. That’s an ongoing debate among baseball analysts – especially as it pertains to Hall of Fame credentials – and probably always will be. Those who argue for consistency and durability regularly point to Palmeiro, who hasn’t been on the disabled list since his first full season in 1988. He’s also outlasted all of the great first basemen of the 1990s, including Thomas, who is three years his junior.

This is not necessarily to say that Palmeiro has been a more productive hitter than Thomas over the past few seasons, but instead that he is still capable of fielding and running the bases on a major league level, while Thomas, who runs the bases like a pregnant buffalo and who has gotten nearly 90% of his at-bats over the last three years as a designated hitter, is a liability any where but in the batter’s box.

In fact, the careers of Palmeiro and Thomas seem designed to highlight the consistency vs. peak performance debate. Thomas, whose rookie year was 1990, has definite Hall of Fame numbers if you don’t examine them too closely – a career batting line of .307 BA/.428 OBA/.568 SLG, 447 home runs, and 1,463 RBI.

But nearly all of Thomas’s great seasons came in the first half of his career, when he was threatening to be the next Stan Musial. From 1991-2000, he hit .317 or better seven times, had an on base average of under .414 just once, and drove in more than 100 runs in nine of 10 seasons. Since 2001, though, he has never hit higher than .271, had an OBA of .400 only once, and has driven in more than 100 runs just once.

Palmeiro’s career has essentially gone the other way. In 1988 – his first season with more than 250 at-bats – only eight of his 178 hits were home runs. He became a star in 1991 when he batted .322 with 26 home runs. Four years later, at 31 – an age at which most players have seen their peak years come and go – he had his best season yet, batting .310 with 39 homers and a .583 slugging average. Then, from 1996-2003, he averaged nearly 42 homers and 122 RBI per season – marks he had never approached in what were supposed to be his prime years.

So who do you like for the Hall of Fame – Thomas or Palmeiro? If you’re like me, neither. The White Sox were ready to dump Thomas by his early thirties, which makes his case difficult to support. As for Palmeiro, I don’t think he is as good as the player he is so often compared to, Eddie Murray, who, though he finished with about 100 fewer home runs than Palmeiro is likely to finish with, was a better hitter and all-around player.

Murray, who played most of his career at a time when runs were much tougher to come by, still managed to reach the 3,000-hit, 500-homer plateau, and was considered a much more valuable player in his day than Palmeiro has been over the past decade. Murray was second in the MVP voting in 1982 and 1983, and fourth in 1984; Palmeiro has never finished higher than fifth. Palmeiro has made four All-Star teams; Murray made eight. In truth, it has only been in the last seven or eight years that Palmeiro has even been considered a legitimate Hall of Fame prospect.

One good thing about Thomas’s late career slide is that no one will accuse him of taking performance-enhancing drugs – and we don’t mean Viagra, which Palmeiro has pitched in TV ads. But that’s not the kind of performance enhancement that may hinder Palmeiro’s Cooperstown ambitions. Jose Canseco, not exactly the most credible source, recently named Palmeiro as one of the players he helped school in steroid use – accusations that Palmeiro has angrily denied. And while there is no corroboration for the charge, Palmeiro’s numbers, when closley examined, do seem a bit strange.

For one thing, though he wasn’t exactly Rod Carew before turning 30, Palmeiro is the only member of the 500-homer club ever to lead his league in singles (with the Rangers in 1990), meaning he bulked up significantly right around the time guys like McGwire and Sosa did as well. More damningly, there is only one other player I can think of in baseball history whose stats after age 32 were so much better than his numbers from ages 22 to 31, and that’s Barry Bonds.

Yes, it’s not fair to cast aspersions on a player without some evidence, but I’m not the one casting the aspersions. I’m just pointing out that Palmeiro’s career is most curious. It’s possible that the only reason the baseball press hasn’t noticed how unusual the second half of his career has been is because he so completely slipped under their radar in the first half.

The sooner Palmeiro retires, the sooner his Hall of Fame eligibility will come up, and the sooner at least some of the questions about his career will come to a head. And that may end up being the biggest irony of Rafael Palmeiro’s career, namely that he will have inspired more spirited debate in retirement than he did in two decades in the big leagues.