Your league seems to be topsy turvy with teams coming from nowhere to win the superbowl only to fade back into oblivion again a couple years later.

It wasn't like that before the salary cap was introduced. Now the "rich" city teams like Dallas and SanFransico don't have an advantage over teams like Cleveland and New Orleans.

www.Wikipedia.com
Unlike other leagues, for example the NBA (which permits certain exemptions) or Major League Baseball (which has a "soft cap" enforced by "luxury taxes"), the NFL has a "hard cap": an amount no team under any circumstances may exceed.

The NFL salary cap is calculated by the current CBA to be 59.5% of the total projected league revenue for the upcoming year. This number, divided by the number of teams, determines an individual teams maximum salary cap. For 2006, this is approximately $102 million per team. For 2007, it is projected that this will rise to $109 million.