Sports Illustrated magazine's November 7, 2011, issue featured the Green Bay Packers, who at the time were undefeated and making a run at the 1972 Miami Dolphins' perfect season. The Packers lost on Dec. 18.

There’s a rumor that the ’72 Miami Dolphins, the lone team to complete a season undefeated, cheer against those who challenge their record. Fact or fiction?

In the NFL, notching a perfect season is so rare that only one team–the 1972 Miami Dolphins–ever achieved it, and in almost 40 years, a handful of teams have come close to challenging it. The 2007 New England Patriots came the closest, falling one game short–and that was in the Super Bowl.

As this year’s Green Bay Packers chased perfection–but finally fell short on Sunday, Dec. 18, in a loss to the Kansas City Chiefs–you might hear many references to champagne celebrations, but the sportscasters aren’t referring to toasting the Cheeseheads’ accomplishments. They’re referring to those 1972 Dolphins.

It’s long been suggested that the surviving holders–coaches and all–of the untouchable record chill a bottle of champagne from that magnificent year’s vintage to be uncorked when the last undefeated team falls every season.

But is that fact or fiction?

In a 2007 ESPN.com article, Don Shula, the legendary head coach of the Miami Dolphins, dismissed the notion that the surviving members of the NFL’s only perfect team gather together to celebrate when their record is still unchallenged–at least for another year.

According to urban myth-buster website Snopes.com, Dolphins defensive end Jim Riley admitted that some of the guys gathered together to toast the continuance of their perfect record–but just once. And even then, it was an informal meeting of three players in a parking lot in South Florida.

In the ESPN article, Shula shot down the idea that he and his former team were cheering for their unblemished record not to be duplicated.

“Everybody thinks we’re a bunch of angry old men who can’t wait for that last team to get beat,” he said. “If that happens [a team goes undefeated], I’m going to be the first guy to call that coach and congratulate him. And our players will do the same thing. But until it happens, that’s a record we’re proud of.”

So why has a nearly 40-plus-year mark yet to be bested? Chalk it up to longer seasons, changes in the game, whatever. But at least for another season that untouchable record of the ’72 remains untouched.