Change is in the wind, but will that change anything for the New England Patriots and the 31 teams chasing them? If you haven't learned not to bet against the Patriots, you're a slow learner.

New England opens training camp Sunday in hopes of becoming the first team in NFL history to three-peat as Super Bowl champions and the first to win four world titles in five seasons. The odds are against them because it never has been done before, but neither had 25 straight wins, losing your starting quarterback and coming on to win your first Super Bowl title four months later or having a 27-year-old quarterback win three Lombardi trophies and two Super Bowl MVPs as quickly as young Tom Brady has.

Still, new challenges abound for the defending champions despite coming off a 14-2 season with a roster that returns at least 19 starters from a year ago and seems to have improved in its areas of greatest weakness: the secondary and the offensive line.

But everything is not perfect in New England these days because coach Bill Belichick must solve a unique problem, the loss of both his coordinators to better jobs.

The defection of one coordinator is expected from teams as successful as the Patriots have been in recent years, but losing both in the same off-season is all but unprecedented. It will create logistical and strategical difficulties that could prove more daunting than the loss of four-time Pro Bowl cornerback Ty Law for salary-cap reasons; Pro Bowl linebacker and the defense's spiritual leader, Tedy Bruschi, to an off-season stroke; or any other player not named Brady.

Defensive coordinator Romeo Crennel left after 25 years as an NFL assistant to become the Cleveland Browns head coach. He was a long time co-worker with and coordinator under Belichick, and they seldom had to waste time discussing what one or the other wanted to do or how they planned to do it. Crennel was the architect of many of the schemes that baffled opposing offenses the past few seasons and he called the bulk of the defensive game, so he will be greatly missed. Crennel also was a calming agent to Belichick's sometimes cryptic and clipped style with unhappy players.

No one doubts Belichick can handle that role again if necessary, because he once was considered the best defensive coordinator in the game. But he's hoping he won't have to get too involved after convincing 34-year-old Eric Mangini to stay by his side rather than leave to run Crennel's defense in Cleveland.

The problems for Mangini are threefold, though. First, after three superlative Super Bowl seasons in four years, he's got nowhere to go but down in his first season being responsible for the entire defense and will be harshly judged by the standard Crennel set, both by the public and, more importantly, by players not much younger than he is.

Second, Mangini never has been responsible for calling a game, a skill that is as much a gift as it is a product of hard work.

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Lastly, he might not have the full attention and aid of Belichick because for the first time, the coach will be calling the bulk of the offensive plays after his longtime associate Charlie Weis accepted the job as Notre Dame's head coach.

Weis was an innovative playcaller whose style could be abrasive at times but was clearly successful. He might call plays early in a game he knew were likely to fail simply to set up something later that didn't. He was a tireless worker, studying film late into the night, and he had much to do with the development of Brady. Weis, like Crennel, seemed a master of putting his athletes in the best position to succeed while avoiding putting them in positions that failed to maximize their talents.