Ten years ago, the Colorado Rockies opened Coors Field, the most extreme hitter’s park in history, which has regularly inflated run scoring by around 30% as compared to a league average park. The problems are well-known – a mile above sea level, the ball flies farther when it’s hit, which it’s liable to be because the dry, thin air prevents breaking pitches from breaking and quickly tires pitchers out. In addition, in a rather ill-thought idea, the park’s designers built a huge outfield, hoping to make it harder to hit home runs but in fact making it easier for balls to drop in for hits, thus ensuring that there would be plenty of men on base when the homers did fly.

Given my choice of what to do with Coors Field, I’d either put a pressurized dome on the stadium or, better still, blow it up and move the Rockies to Brooklyn or Montreal. But in the meantime, the park poses a few interesting questions, not least of which is what to make of any Hall of Fame candidates who happen to have run up their numbers there.

As it happens, there are only two of those to this point in the Rockies’ brief history. One is Larry Walker, who has every attribute of a truly great player save durability. That’s a big one, though – through his career Walker has averaged 123 games a year, which to my mind removes him from serious consideration as a candidate despite his excellent .313 AVG/.401 OBA/.567 SLG career batting line.

The other is Todd Helton. Depending on who you’re asking, he’s either the most underrated or most overrated player of his day. He may be both.

Pick an arbitrary achievement and Helton is there. For instance, did you know that Helton has hit .300 with 25 home runs and 100 runs in each of the last six years? Or that Lou Gehrig, Babe Ruth and Willie Mays are the only players in history with longer streaks?

Such an achievement doesn’t mean a whole lot when a player spends half his time hitting in Denver. “Thin air,” scoff the critics. Still, it’s not as if we don’t know how to let the air out of Helton’s numbers. Just for starters, look at his home/road splits.

The differences are startling: Coors increases Helton’s home runs by 63%, adds 75 points to his batting average, and generally turns him from an All-Star caliber hitter into Babe Ruth. A few factors, though, are worth keeping in mind.

First, most every hitter enjoys a distinct home-field advantage, so it’s not fair to simply double Helton’s road line and say that’s what his stats would look like if he didn’t hit in Colorado. Second, the NL West features a number of severe pitcher’s parks, so there’s actually quite a damper on Helton’s road stats.

Third, some studies have suggested that Rockies hitters are plagued by a “Coors hangover.” The theory, which makes good intuitive sense, holds that between the physical effects of altitude and the effects of not seeing good breaking balls during home stands, Rockies hitters perform much worse on the road than their talent would suggest.

Fourth, Helton has a reputation as an absolutely superb fielder, which defensive statistics do nothing to dispel. It’s possibly just an illusion based on so many balls being in play in Coors, but the numbers suggest Helton may be a fielder of historic stature, on par with Keith Hernandez. That doesn’t show up in his hitting line.

Despite all that, Helton’s road numbers suggest that even without Coors, he’d be halfway through a Cooperstown career, essentially like a more consistent and more powerful Hernandez or John Olerud with fewer down years. That’s not faint praise: The former Met first basemen were better ballplayers than many Hall of Famers. Hitting .300 with line-drive power and Gold Glove defense every year, they were more valuable than Tony Perez, Orlando Cepeda, or Mark McGwire. If Helton avoids injury, stays productive for another few years, and avoids the sudden decline Olerud and Hernandez suffered, he’ll certainly deserve a plaque in Cooperstown.

Whether Hall voters will recognize that is another question. But Helton is hardly the first excellent player to thrive in an extreme environment: Even playing in Coors during an offensive boom, he hasn’t approached the all-time champion in that department, Chuck Klein.

Playing for the Philadelphia Phillies in 1930, Klein, then just 25 years old, stroked 250 hits, 107 of them for extra bases. He drove in 170 runs, scored 158, and walked more than he struck out; his batting line was .386/.436/.687. In his career, he had four more very good seasons, and another handful in which he was anywhere from solid to a minor star. Thirty-six years after his career ended, in 1980, he was elected to the Hall of Fame.

As many of you know, 1930 was an unusual year. National League teams averaged 5.68 runs per game that year; at the height of the recent offensive explosion, in 2000, NL teams averaged only 5.00. In 1930, four of eight NL teams scored at least 944 runs; in 2000 one team among 16, Helton’s Rockies, scored that many.

Not only was Klein hitting in the most hitter-friendly league the game has ever known, he was hitting in the infamous Baker Bowl. To give an idea of how hitter-friendly its dimensions were, it was 272 feet from home plate to a wall that reached from right field into center – 106 feet less than the right-center wall at Shea Stadium. The Phillies averaged 7.05 runs scored per game there, and 5.08 elsewhere. Pitifully, their pitching staff allowed 8.36 runs per game at home, and 7.03 on the road; with a lousy staff and what was, in context, an equally lousy offense, the team went 52-102 and finished 40 games out.

Klein, despite putting up monster numbers, led the league in only three categories: runs scored, doubles, and total bases. His 170 RBI placed him 21 behind the league leader, Hack Wilson, who of course holds that record to this day. In context, Klein’s 1930 campaign, while excellent, was about as good as Bernard Gilkey’s 1996 (the former Met, it is worth recalling, hit .317/.393/.562 with 30 homers and 117 RBI). Helton has had four or five better seasons.

Putting Klein in the Hall of Fame because he had five good seasons playing his home games in the Baker Bowl was ridiculous, and an example of how statistics need to always be kept in context. Putting Helton’s numbers in context show him to be among the better players of his day, if not a legitimate .340 hitter. Rumors have the Rockies looking to deal him, perhaps to Baltimore; here’s hoping Helton ends up in a place where they play real baseball, if only so people will believe how good he is.