The Pats had a ton of luck - which takes nothing away from them being well run, well coached and well quarterbacked.
The biggest luck they had was the fact that their division rivals bumbled their way through 2 decades. Without doubt, New England's excellence had something to do w/ that. But it was more than that. It was really a perfect storm of all 3 teams failing to find a true top-tier QB, or coach, and never giving the Pats any kind of challenge to win the division, and even to get the 1 or 2 seed most years.