The brutal truth: Mavs can't repeat

Dallas and Dirk Nowitzki just don't have the horses to repeat last year's playoff run. David Richard/US Presswire

For the Dallas Mavericks, the 2012 season has been an advanced-placement class in the perils of the "championship hangover," a powerful force that drags down title-winning teams after they reach their sport's mountaintop.

Although it's been part of conventional wisdom forever (even being referenced in a 1942 newspaper article), the hangover's existence can also be proved statistically. After adjusting for the spread of competition in each season, 97 of the last 134 champions (72.4 percent) in North America's four major professional sports saw a decline in winning percentage the year after capturing their league's title.

Whether due to psychology (winning has been known to breed complacency), aging, tougher schedules, having the proverbial "target on your back" or even good old-fashioned regression to the mean, there's definitely an invisible anchor that weighs down defending champions.