Why do you argue statistics and probabilities if you don't understand how they work? First of all I'm well aware when each seed was introduced and the numbers have been grouped accordingly for each time segment. No the system isn't designed for perfect parity. That is nonsense. First of all, despite parity, seeds are not exactly of equal strength. Second of all, it is designed, to produce more #1 and #2 seeds in a Superbowl, both as appearances and as winners compared to any other. This is a fact. It requires only 3 wins for a #1 and #2 seed to win a Superbowl. Plus they have homefield advantage. It requires 4 wins for seeds 3-6 to win a Superbowl. You would EXPECT over any time period for #1 and #2 seeds to appear and win more Superbowls than any other. It is designed that way. And for the longest of time, all the way up to about the early 2000s, it worked exactly as designed with some minor fluctuations. There were NO changes in the playoff system in 2005. None. But the results began changing drastically without any sort of explanation that would account for it. It deviated so far off what anyone would expect, and what this format is supposed to produce in terms of probability, that there is no way in hell, this is a natural occurrence. If you wanted the type of results that they have been churning out, then some serious changes would have need to take place in the playoff format. They got the results, without any changes. It's been hand picked. Somebody got tired of #1 and #2's popping up in the Superbowl just about every year and winning it which is something that happened very regularly in the history of the NFL. It was very predictable. It was what the system was designed to produce and was working just fine. It just wasn't very exciting. Over 30 years the #1 seed was about a 55% winner of Superbowls, and #2 seed about a 45%. In general though, ANY seed was roughly 50-50 in a Superbowl. The problem is once again for about the past 10 years, the #1 seeds are losing 80% of the time. The lower seed is dominating the higher seed 80+% of the time. Once again, a pretty significant deviation.