Only one undefeated team remains: the 5-0 Minnesota Vikings. Nine teams, however, have just one loss, with six at 4-1 and three at 3-1.

With every team at least 25 percent of the way through its schedule, we are checking the #PulseOfTheNation:

The Vikings have reached rarefied air, despite Teddy Bridgewater's preseason injury and Adrian Peterson's being out the past three weeks. The New England Patriots (4-1) struggled in a home loss to the Buffalo Bills last week but welcomed Tom Brady back in a road win at the Cleveland Browns. The defending champion Denver Broncos (4-1) have navigated the post-Peyton Manning era well, but they suffered a setback (with quarterback Trevor Siemian out) against the 4-1 Atlanta Falcons. The Pittsburgh Steelers (4-1) have looked downright unstoppable at times but were handled by the surprising Philadelphia Eagles (3-1), who just lost their first game.

Speaking of surprises, the Dallas Cowboys and Oakland Raiders are 4-1, well ahead of expectations. The Green Bay Packers and Seattle Seahawks, meanwhile, are high-expectation teams currently sitting at 3-1.