Let's see
Raiders, 81 and 84
Redskins 82 and 88
Niners 80, 85, 89
That's 7 Super Bowls won by three teams. Add the 1980 Steelers (the last of 4 SB) the 1986 Giants (who in 90 would win their second SB) and then the FLUKE 85 Bears. Who are still waiting for a return trip to the Super Bowl. If winning a championship every 21 years isn't a FLUKE, I don't know what is. 63. 85. 2006??? With the losers on and running the Bears that's really going to happen.
Is that so hard for you to figure out? Oh don't answer that, it may take you forever to figure it out, moron.