Belichick really needs no more additions to his résumé. He is generally regarded as the NFL’s best head coach, and perhaps the best ever. If the Patriots get this far and lose, he will remain among the elite of the elite. Yet his aura of invincibility, which has been carefully sewn together little by little this season in anticipation of a history-making event, will unravel. He’ll still be a great coach, just not a god.

As for his Giants counterpart, Tom Coughlin, it’s safe to say his job security will improve as a result of upending the unstoppable Patriots. Coughlin already is safe, given the way he reached out to players this season, altered his approach, improved his people skills and convinced his guys they could get this far.

But if he outcoaches Belichick and spoils the Patriots’ season? Coughlin will assume — dare I say it? — Bill Parcells-like stature in and around the New York metropolitan area and across the entire football landscape.

A Giants’ stunner against the Patriots will have an impact on everyone directly involved, from Randy Moss (Can he continue to be a good soldier in the face of adversity, or will he turn into T.O.?) to Junior Seau (Will he give up his quest for a Super Bowl ring?) to Michael Strahan (Will he use a Giants’ championship as a springboard to a career as a TV personality?) to Tiki Barber (Wouldn’t he look like a world-class idiot for ripping into Eli earlier, not to mention retiring when he did?).

But such an upset will also stagger fandom.

There are no sure things in sports. History has taught us that time and time again. Yet these Patriots might have come the closest in recent memory. If they lose, it threatens our entire belief system. What’s next? Dogs and cats living together?

Super Bowl XLII interactives Matchups: Who has the edge? Compare Pats, Giants lineups X-factors  |  Fans’ photos

A Giants victory will help illustrate to sports fans that anything is possible, that the lowly high school team can knock off the league Goliaths, that Tiger can choke on Sundays, that Josh Beckett is hittable, that Roger Federer can be stopped (see weekend results), that just about anybody or anything that is considered unbeatable can be beaten.

If the Patriots fall, it shouldn’t be much of a surprise at all, considering the fact that in sports we should all be conditioned by now not to ever be surprised. If George Bailey can dig himself out of his financial hole, anything is possible.

Don't miss this on MSNBC.com Pass it on: Sons of infertile men may be next The eight biggest Olympic marketing debacles Reality show judges range from wise to wacko Cosmic Log: Is this your jetpack? Forget your inhibitions: World's sexiest islands