On the day Babe Ruth became the first member of baseball's 600-home run club, he was also the only member of the 500-, 400-, and even 300-home run clubs, and it seemed entirely possible that he would remain forever alone atop those superhuman numbers.

On the day Jim Thome reaches the same plateau, he will become the fifth major leaguer in less than a decade to scale those Ruthian heights.

See, the salaries aren't the only things that became inflated.

"It was an inconceivable number in Ruth's day, but a lot of the mythology about 600 has sort of been stripped away," said David Vincent, a Society for American Baseball Research historian who is considered the sport's foremost expert on home runs. "The fallout [of baseball's 1990s and 2000s power explosion] has fallen on other people a little unfairly, and Jim Thome is a good example."

That's because so many home run records of the past 15 years have been tainted by performance-enhancing drugs, either by admission or suspicion, and the public's fascination with round numbers has been greatly reduced. "Media coverage is the big change -- it's no longer reported necessarily as a positive when someone hits a lot of home runs," Vincent said. "Jim Thome has never been anywhere near those stories, but it certainly seems people aren't paying as much attention to what he's accomplishing as they might have years ago."

He might be right, although "attention" is relative: There were only a few thousand fans on hand in St. Louis in 1931 when Ruth reached the round number that Thome now threatens, and 4,771 were in the stands in San Diego in 1969 when Willie Mays joined him. But there is little doubt that steroids have changed the way people view those once-unreachable benchmarks.

"The bottom line is, it happened. But not every guy in that era did [performance-enhancing drugs]," Thome said. "It was part of our era, but look at baseball now -- baseball has done a good job of cleaning up the game. Guys did it back then, everybody knows it. But you can't punish everybody for it."

Still, seven of the past 10 sluggers to reach 500 homers have been linked in some way to steroids, and three of the past four members of the 600 Club (Barry Bonds, Sammy Sosa and Alex Rodriguez) carry similar suspicions. But that shouldn't diminish the feat in Thome's case, current players and managers agree.

"I can't even comprehend it, as a player and a manager, that many home runs. But it's sure fun to watch," said Twins manager Ron Gardenhire, who has witnessed the 34 home runs Thome has hit for the Twins and all 57 home runs that he hit against them -- more than any opponent in franchise history. "Chasing 600, that's pretty good. I do that in bowling. In three games."

Said Twins outfielder Michael Cuddyer: "It's a tribute to his consistency. To keep up that sort of production for that many years, it's one of the most impressive things I've ever seen."

History lesson

Thome, whose home run total stands at 598, considers himself a student of the sport's history, so he understands the rarefied stratosphere he's about to reach. After Ruth blasted No. 600 in 1931, it took 38 years before Mays got there, then two more for Hank Aaron to arrive. Those three were by themselves until Bonds joined them in 2002, followed by Sosa in 2007, Ken Griffey Jr. in 2008 and Rodriguez on Aug. 4, 2010.

Even with all the latecomers, Thome said he is awed by the company -- and reluctant to consider himself part of the club until the historic baseball reaches the seats.

"I haven't gotten there yet, so I don't assume anything. I say that out of respect to the game," Thome said. "It's a big number, a special, special number. But I don't want to make it about a number -- I want to play to win games. I imagine it would be a very special thing if it happened, but that's not why I'm here."

No, but his home runs have provided plenty of wins. Thome's first career blast, matter of fact, was an upper-deck shot at Yankee Stadium in 1991, a two-run homer with two outs in the ninth inning off Yankee closer Steve Farr that turned an imminent 2-1 Indians loss into a 3-2 victory.

"Joel Skinner let me use his bat, and told me, hey, be ready for the fastball inside," Thome said. "We laugh about it today. He likes to take credit for it, the old wily veteran to the young rookie."

Thome's 500th home run was a walk-off job, a blast to center to beat the Angels in the bottom of the ninth of a 2007 game. And Twins fans will never forget Thome's deep drive to center off Nick Blackburn, the lone run in the White Sox's division-clinching game in the 2008 one-game tiebreaker.

A long time coming

It's not a bad legacy, no matter how you feel about home run inflation. Asked to compare Derek Jeter's chase for 3,000 hits with Thome's stalking of 600, for instance, Tampa Bay manager Joe Maddon said the home run milestone impressed him more.

"I'd say probably 600 home runs is more difficult to achieve," Maddon said. "If you look at the number of 3,000-hit guys [Jeter was the 28th], does that exceed the number of 600-home run guys? From that perspective, I think that would be the one way to look at it. But both are awesome accomplishments, and both are really deserving, classy individuals."

And unbelievably productive besides. Thome has hit 20 or more home runs in 16 of the past 17 seasons. He has hit a home run every 13.57 at-bats during his career, which ranks fifth in baseball history. And when he hits No. 600, he will become the oldest player to have done it.

"I was fortunate enough to play with Eddie Murray and to play with Dave Winfield, guys with such tremendous careers, and I asked them what makes a great career. And they both said longevity. Being able to play, to help your team, for a long time," Thome said. "And I've been granted a great gift to be able to do so. Playing into your 40s is really cool, because it means you're someone who worked your butt off to do it. It makes you appreciate it that much more."

Hitting 600 home runs should buy a lot of appreciation.