The Saints were 9-4 and had 3 EASY games left... and lost their way out of the playoffs. SD Chargers were 6-1, the Broncos were 6-2, the 'Phins were 5-1, and all found a way to miss out... The defending champion Patriots were 8-5 and hot (winning 5 of 6), but couldn't get in.
On the other side of the coin, the Jets and the Titans both start 1-4 (both losing 4 straight)... the Browns were 2-4 and even found a way to lose a game after the clock had expired.... Oakland was collapsing into a 4-4 record (losing 4 straight)... Pittsburgh and Atlanta started 1-3 (and tied each other later in the season)... the Giants were 3-4... and all are in at the end.