FOXBOROUGH, Mass. — For some franchises, four years is a fragment of time. For the New England Patriots, it is a millennium. Their transformation over that span has been swift and overarching. Their offense, if possible, is more capable and explosive. Their defense is not as formidable or feared. The imbalance created the perception that they were too flawed, too unreliable, to restore glory to Patriot Place.

Indeed, the Patriots are hardly perfect. But they are the best team in the A.F.C., a distinction earned Sunday with a 23-20 victory against the Baltimore Ravens. New England escaped when Billy Cundiff hooked a 32-yard field-goal attempt wide left with 11 seconds remaining.

“It’s a kick I’ve kicked a thousand times, and I just went out there and I didn’t convert,” Cundiff said.

As the ball sailed outside the goal post, the Ravens stood on their sideline as if their feet were entombed in concrete while the Patriots spilled onto the field, overcome with euphoria, with that feeling many of them know so well. Of returning to the Super Bowl.