Pats fans are enjoying their team's dynasty, history shows it doesn't take much for a run to end. Jodi Hilton/Getty Images

I don't like to use the word dynasty, even though everyone else seems to find it a perfect description for what the Patriots have become. To me a dynasty suggests a long progression of rulers, ideally of the same family, following in a line of interminable length. Hapsburgs, Ptolemies, Medicis of Florence, heel-and-toeing their way, single file, through hundreds of years of history; those are dynasties.

A football team that wins two straight championships, skips a year or two, then wins one or two more, I'd call it a ... help me find a synonym for dynasty, Roget ... a succession, a reign, part of a ruling cycle perhaps. That last one makes more sense. And what I'm looking at right now is how far we can take the Patriots on this progression, if they are truly ready to step into the terra incognita of three straight championships.

No one ever has done this, unless you want to count the Browns' four straight championships in the All-American Football Conference. But I believe the Patriots could do it and fortify their status as rulers of the cycle. They seem to be dedicated to avoiding the pitfalls that brought down the lords of the past, although some are impossible to escape, and a certain amount of luck is needed.

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So as an off-day project I drew up my own list of teams that commanded a ruling cycle, teams people describe as dynasties, and what did them in. How it all ended, for them. Qualifications for membership in the club include sustained excellence over a period of time, highlighted by two repeated championships. This is important, the ability to successfully defend a title. OK, I let one club slip in through the back door, the Packers of the late 1930s.

In the space of four years, they won two championships, not in succession, and lost a close one to the Giants in a third. Why do they make it when a team like the Raiders, who won three Super Bowls within eight seasons (1976-83), albeit with down periods in between, did not? Oh I don't know. Whim, I guess. I just kind of like those Packers teams, with Don Hutson and Buckets Goldenberg and the twin passing phenoms, Cecil Isbell and Arnie Herber. In chronological order, then (and Hall of Famers cited only include players, not coaches or club officials), here is my lineup:

1936-39 Green Bay Packers: NFL Champions in 1936 and '39, lost title game of '38. Five Hall of Famers. Dazzled the league with their aerial game, the most prolific in football during that era. Herber and Isbell, a rookie star in '38, occasionally appeared in the same backfield together, and either one was a threat to pass. And they were throwing to, Hutson, the greatest receiver the game had known until Jerry Rice came along almost 50 years later.

What did them in? Nothing of their own making. It was the rise of the Bears, the Monsters of the Midway, with an unbelievable array of talent. Green Bay was a top-level team for five more years, with another title in 1944.

1940-46, Chicago Bears: NFL Champions in 1940, '41, '43 and '46. Lost to Washington in the '42 title game. Seven Hall of Famers. Lost only five games in the four-year period of 1940-43. Once I asked Bronko Nagurski, the star of the 1930s, why he never put up big numbers, such as 100 yards rushing in a game. "George Halas believed in spreading things around," he said. "He always had a million running backs. He overwhelmed people with masses of troops. Don't forget, we had to play defense, too."

And what troops. The team that slaughtered the Redskins, 73-0, in the '40 Championship was young. Next year, when Chicago beat the Giants, 37-9, there was even more material. No one had ever seen such depth among halfbacks and fullbacks. For instance, Hugh Gallarneau and Norm Standlee from Stanford's unbeaten Rose Bowl team jointed the stars of 1940, the flashy George McAfee, the big bangers, Bill Osmanski and 220-pound Gary Famigletti, and on and on. No less than 10 running backs shared the wealth, which produced an average of 208 yards rushing per game.