The altitude?

That’s my best theory as to why the four major professional teams in Colorado have no mental toughness when it comes to pulling through in the big moments of big games. I dare you to find a Denver-based team in recent memory other than John Elway’s back-to-back Super Bowl teams or Joe Sakic’s 2001 Stanley Cup team that excelled in the spotlight

The Broncos, Rockies, Nuggets and Avalanche have all had their chances to compete for championships in the last decade. And yet, the last time the citizens of Colorado celebrated one of their teams being the best was that 2001 Avalanche squad.

After that Stanley Cup, the Avs have been on a downward spiral, stamped just several days ago by the retiring of longtime star Milan Hejduk and firing of coach Joe Sacco.  As bad as they were this year, they had several chances in the 2000’s to get back to the finals.

In 2002-03, they blew a 3-1 series lead against Minnesota in the conference quarterfinals despite Peter Forsberg being named the most valuable player. The next year, the Avs had an All-Star team with the additions of Teemu Selanne and Paul Kariya and choked in the conference semifinals to San Jose.

After the lockout in 2004-05, the Avs have made a few brief playoff appearances with lesser talented teams. They finished this season with the second-worst record in the league and don’t appear to be playoff contenders in the near future.

The Nuggets took the western conference by storm this season, notching 57 wins and the third seed in the playoffs. But Nugget fans know that the first round of the playoffs in the George Karl era means an early exit from the powder blue, save for 2009.

What’s most disturbing is that they have looked clueless during the majority of the Golden State series. Stephen Curry constantly makes the Nuggets’ defense look likes his puppets. And Andrew Bogut has made a habit of stealing lunch money from the Nugs’ big men on more than one occasion in the paint.

The Nuggets avoided elimination Tuesday with a home win against the Warriors, but it’s not that encouraging. They should have won going away, by 20. Instead, they refused to match the intensity and mental strength of Golden State in the second half and made things way too interesting in the fourth quarter. I hope I’m completely wrong, but the Nugs don’t look like they’ll force a game seven back in Denver.

Whether or not Karl comes back next season, the Nuggets need changes. Everyone on the team except Ty Lawson, Kenneth Faried and Danilo Gallinari is expendable. They could use several gritty veterans, one or two bona fide shooters and a legitimate star. Unless the front office brings in mentally tougher players, the Nuggets will continue to lie down in the playoffs.

The Rockies have been a punch line in major league baseball discussion since their existence. Three playoff appearances in 19 years will do that. But they’ve had good teams in the past that didn’t perform up to expectations.

The 2011 team was picked by many to win the National League pennant. They had a feared lineup backed by Ubaldo Jimenez, who was supposed to be the Rox ace for the next decade. Jimenez wound up being traded before August and the Rockies won only 73 games.

In 2013, the Rockies have been given little chance to compete in the NL West. But as we turn the calendar to May, they’re atop the division. Recently against Atlanta and Arizona however, the club has been a mirror image of 2012.

Stupid decision-making, lack of discipline and inability to make the clutch pitch or get the clutch hit have killed the Rockies during the past week.

This is now Troy Tulowitzki’s team. Being tabbed as a player that fails to come through in the clutch, Tulo has shown the ability so far this season to have a slow heartbeat during pressure situations. If he continues that trend, the Rox have a legitimate chance to contend for the next six seasons.

Surprise, surprise. The Broncos have the best chance of bringing home a championship to Denver in the next few years under the leadership of Peyton Manning.

If they don’t reach the Super Bowl before Manning retires, Broncos’ country can’t say their team didn’t have a chance. We’ll never forget the Mile High Meltdown on that arctic January afternoon that slingshot Joe Flacco’s Ravens to a Super Bowl win.

Remember 2005? The Broncos were a home win away from reaching the Super Bowl (where they would have played an inferior Seattle team). Instead, Ben Roethlisberger and the Terrible Towels broke Denver’s heart en route to another Pittsburgh Super Bowl parade.

Manning has gotten help via free agency and the draft. Sure, football is the ultimate team game. But there will undoubtedly come a time during a Broncos’ playoff game next season where Manning will have to make a play, something he failed to do against the Ravens in crunch time.

For now, it’s Tulo’s turn to be clutch. Come September, it will be Manning’s. The Nuggets and Avs won’t be taken seriously in playoff discussion again for years. It’s time for the Rockies and Broncos to suck it up and start winning when it counts.