Contender Angst Index: Top NFL teams off to the worst starts

Clark explains why Bell's absence is now being exposed (2:06)

After a 26-14 loss to the Ravens, Ryan Clark explains why the Steelers' offense has been stagnant without Le'Veon Bell in the backfield. (2:06)

The New England Patriots and 10 other NFL contenders entered the 2018 season as clear Las Vegas betting favorites to win the Super Bowl.

Several of those teams, such as the Minnesota Vikings, who are staggering after the first month, have not met those high expectations. Other favorites, most notably the Patriots, appear to have steadied themselves for now, despite some serious concerns.

"I think the Patriots believe they're back and everyone else believes it, but are they?" an exec asked Sunday night.

The angst levels remain nerve-wrackingly high even for some of the contending teams that prevailed in Week 4 (here's to you, Los Angeles Chargers). I've placed these 11 preseason favorites in categories that represent each level of angst, from one extreme to the other.

Each contender below includes its preseason Super Bowl odds, plus its updated chances for reaching the Super Bowl this season, courtesy of ESPN's Football Power Index (FPI). The Westgate Las Vegas SuperBook listed all of these teams' Super Bowl odds at 14-1 or better entering the season. None of the league's other 21 teams was given anything shorter than 25-1 odds.