This NFL yearly trend has a very one-sided edge in its' favor and the trend is very straight forward. I came upon it about seven years back and have been following it each season to see if the trend continues to follow suit on a positive note. Now I haven't done a study lately to see where the trend stands based on a "make it or miss it" record but I do recall it was very solid the last time I did a quick review. In short here is how it reads:

One or both of the two teams that plays in the Super Bowl will miss the playoffs the following season.

This year of course I have my eyes focused on the Saints and Colts and when the season began, the odds that the trend would hit appeared to be slim to none given the overall talent on both these clubs. New Orleans and Indianapolis combined for a stellar 27-5 win-loss regular season record last year on their way to the championship game in Miami.
However heading into week 13 tonight, both the Colts and Saints most definitely have their work cut out for them as they work their way toward a possible postseason birth. A division title is of course the easiest way to solidify a playoff birth but avoiding that route makes for a definite grind to lock on to one of two conference wildcard spots. The Saints, at this point, look to be headed for the alternate route while Indy is in a current dogfight with the Jags for a division title in the AFC south, with Houston and Tennessee following close behind.
With five games remaining in the schedule, it'll be very interesting to see if one or maybe even both of these two clubs miss out on this year's postseason to keep the trend in tact for yet another year.