2012 champs: Houston Texans
Likeliest threat in 2013: Indianapolis Colts
Indy is listed for a simple reason: quarterback play. If we were going 21-on-21, then the Tennessee Titans certainly could stake a claim, what with the improvements they've made this offseason. Nonetheless, Andrew Luck > Jake Locker. Acquiring veteran back Ahmad Bradshaw only helps the Colts' cause here; if their young quarterback gets some ground support, he won't have to put the whole game on his shoulders. Defensively, Indianapolis re-tooled its roster with mid-tier free-agency acquisitions in Ricky Jean Francois, Erik Walden, LaRon Landry and Greg Toler, as well as top draft pick Bjoern Werner.
How it can happen:
» Toler and Landry need to ball out. The Colts' defense finished 21st in passing yards allowed and tied for 20th in interceptions, while producing just 32 sacks. A few "coverage" sacks would help. So would more pass rush. Hello, Mr. Werner.
» New offensive coordinator Pep Hamilton has to pick up where the departed Bruce Arians left off, building on Luck's growth while developing a consistent running game.
» Reggie Wayne has to avoid pulling an Andre Rison/Hines Ward -- that is to say, he has to avoid hitting the wall. Wayne turns 35 in November.