JACKSONVILLE, Fla., Feb. 7 - In the frantic final days before Super Bowl XXXIX, with schemes to study and history to clutch, the New England Patriots dispatched members of their personnel department to begin scrutinizing salary-cap numbers and college rosters for the draft in April.

Those are some of the behind-the-scenes maneuvers that have elevated the Patriots above the gravitational pull of parity. By preparing for every possibility -- be it a coaching departure or the loss of a player -- Coach Bill Belichick has rarely been caught unprepared.

"A lot of coaches in the N.F.L. work hard," Jimmy Johnson, the former coach of the Dallas Cowboys and the Miami Dolphins, said in praising Belichick last week. "But there is a difference between working hard and working smart."

The Patriots stamped themselves as a dynasty Sunday with their 24-21 victory over the Philadelphia Eagles at Alltel Stadium for their third Super Bowl title in four seasons. But New England's bid to claim a fourth Super Bowl crown next season -- and a third straight, which would be a first -- will face its most challenging test since the run began.