Now that the Green Bay Packers have won the Super Bowl, all you read about is how this could be the next dynasty in the NFL.  What the scribes are saying about the Packers is the same thing they said about the Saints last year. 

In the age of modern sports, dynasties are rare.

In only one of the four major sports is having a dynasty not too difficult: The NBA.  The NBA requires the smallest amount of players to field a team.  If five of those are really good, the chances are you can repeat (Bulls, Lakers, Spurs.)

In the NHL, it's a lot tougher, as the Blackhawks are finding out.  The salary cap is a kliller, not to mention that it takes many more players to field a quality team.  Remove several of them (as the cap forced the Hawks to do) and you'll wind up out of the playoffs. And in the NHL, that's hard to do considering sixteen teams make the playoffs.

 The NFL has fluid rosters, with payers lost to free agency and injury.  The salary cap is also a factor as re-signing some of your stars may not be possible in order to keep younger, developing players. Drafting the right players is another key. The Packers got healthy when they needed to and won the Super Bowl, but over the grind of an entire season, sometimes your team breaks down.  Add to that the limited playoff slotting in the NFL and you have a good chance not to repeat.  Honestly, I can't explain what happened to the Saints this year.

Baseball is the hardest sport for a dynasty.  Over the course of a 162 season which leads to eight playoff slots for thirty teams, anything can happen.  Usually, those in contention will have a different roster at the end of the season then they did at the beginning.  The teams who spent the most money, hope their big guns can contribute.  But if Carl Crawford hits .226 this year, the Red Sox, as good as they look on paper, will not do well.  And, then there is always a team that gets max contribution from everybody, stays relatively healthy and shocks the world.  In 2005, that team was the Chicago White Sox.

My advice to anyone whose team has won a championship: Buy the gear, buy the magazines, buy the photos and the memorabilia.  Because, you might never pass that way again.