While there are legitimate issues with Forbes's calculations, they're effective enough as a ballpark figure. The magazine's Top 50 includes nearly every NFL franchise, seven each from soccer and MLB, and a smattering of NBA, F1, and NHL teams. (The Maple Leafs are the only hockey team to make the list.
You can check out the full interactive graphic here. It lays out the teams on axes of championships won, and of number of years in existence. The bigger the bubble, the higher the valuation. Here are the NFL's inclusions.
The big numbers are clustered toward the right, the league's grandes dames from the leather-helmet era. Despite having just a single Super Bowl between them, the Bears, Eagles, and Browns all crack Forbes's Top 20.
There's another cluster of franchises from the AFL and pre-merger era, but there, the money lies in historical or recent success. The Cowboys and Patriots are fifth and sixth overall.
One franchise to buck this trend is the youngest: the Houston Texans, with just two playoff appearances in 11 years. Whether it's a combination of playing in one of the nation's largest markets and that mint of a stadium, or just the bloom on the rose, remains to be seen.
The MLB teams:
It takes time to build a brand. The teams on the list, with a single exception, are baseball's historic franchises. The Yankees, Dodgers, Red Sox, Cubs, Phillies, and Giants.
That exception? The Mets, whose worth can't be explained by on-field success. But the New York market is a healthy one—the Knicks top the Lakers and Bulls on the NBA chart.
The soccer clubs:
No surprises here. Real Madrid, Manchester United, and Barcelona take the Top 3 overall spots on Forbes's list.
August sides all, with the youngest being Chelsea, but that's more a function of soccer's history than anything else. The most valuable "new" franchise, which doesn't come close to cracking the Top 50, is Olympique Lyonnais, formed in 1950.