There are different aspects to "peaking in December," as we saw with the Texans and Bronco's. Like most teams before them the Bronco's were unable to run out a long winning streak in the regular season to a SB championship. That's not unusual and in fact is the norm, teams simply don't run off 13-14 game winning streaks to a title very often, so the fact that they were unbeaten in December didn't so much mean that they were peaking. The Texans in the other hand needed wins to get the bye and couldn't get them against teams they should have beaten, Minny and Indy, and that's the mark of a team that is slumping.