there is no parity,otherwise the Giants, Steelers, Ravens, Patriots, Packers,Colts, Broncos wouldnt keep getting in the playoffs.
Look at the last 20 years or so.
There are no dynasties, like in baseball. Teams have gone from worst to first and back again.
The constant is the FO. If an owner, HC, GM, and staff get it figured out, they can have a successful run, with that continuity as a major factor.
The Cowboys had one of the longest winning and playoff streaks in history, but they lost their formula, and it took several years to get it back (with Jimmy).
That broke up, and we've been down ever since, but looked good last year.
Look how long the 49ers were on top -- they've been mostly down since, but hey put something together with Harbaugh and Kaep, and rebounded for a short while.
The difference in the modern capped and schedule-adjusted era is that there isn't as much distance between the top and bottom. Many teams really are just one or 2 players away, but those difference-makers can end up being lost instead of found.
Some of the teams you mentioned are actually not currently dominant; the only one on the list with any sort of run is the Patriots.
Denver has been fairly steady as well. But you take away some of their continuity, like at QB or key coaches, and they start to look more average.
That's what Rozelle wanted -- a bunch of average teams, so that everybody is in every game.
Like it or not, he has mostly achieved the objective.
