Las Vegas ? The AFC championship game was still in the third quarter, but the wise guys had seen enough. In small rooms inside glittering casinos on the Las Vegas Strip, they came up with the most anticipated — and most important — number of the NFL season.

You won’t find it on NFL.com, because the league likes to pretend the number doesn’t exist.

But by Monday morning, it was already the talk around office water coolers and inside truck stop diners across the nation.

Can New England win a second straight Super Bowl — make that three in four seasons — by beating the Philadelphia Eagles? Probably.

The real question is: Can the Patriots cover the 6 1/2-point spread that oddsmakers put up Sunday night even before New England was done routing the Pittsburgh Steelers?

That’s the question millions of Americans will be trying to answer in the next two weeks as the hype builds to a Super Bowl game climax on Feb. 6 in Jacksonville, Fla.

They’ll come to Vegas with wads of cash, bet with the corner bookie, or punch a few keys to link up with an Internet betting site. They’ll buy squares at bars, get in office pools and wager with the neighbor next door.

They’ll make big bets, small bets, stupid bets and crazy bets. Some will bet their favorite team with their heart; others will bet the opening coin flip comes up tails.

By the time they’re done, billions of dollars will have changed hands.

Like it or not, betting and pro football are joined at the hip. The lines that came out of Las Vegas in the ’40s and ’50s helped make the league what it is today, and the amount of money wagered on pro football grows unabated every year.

The NFL doesn’t need betting booths in stadiums, but it should understand that it no longer needs to hide from the point spreads. The league could even use them as a promotional tool — on its broadcasts, on its Web site and programs sold at games. What kind of spread did Joe Namath overcome in Super Bowl III? You won’t find that out from watching NFL films.

And fantasy football is openly discussed on NFL.com, the NFL Network and during just about every broadcast, but not too many fantasy football leaguers play just for fun.

Every NFL game is so scrutinized on the field and in the sports books that even players who wanted to throw a game wouldn’t be able to. What kind of money would it take for a quarterback earning $10 million a year to put the fix in?

“The NFL should thank the Lord every day that Nevada has the regulatory agencies that are able to assure betting is legitimate on football,” Las Vegas Mayor Oscar Goodman said.

Forgive Goodman for sticking up for his town. He would like to see an NFL team in Las Vegas, but that’s not likely to happen anytime soon. Just two years ago, the NFL refused to even allow a Super Bowl ad promoting Las Vegas as a place to visit.

At the same time, the league allowed advertisers to fork over $2 million or so a shot to air erectile dysfunction drug commercials laced with sexual innuendo. It also thought it was fine to have talking frogs and cute dogs promote the virtues of drinking beer.

And so, while New England and Philadelphia have rabid fans who care deeply about their teams, there will be millions more watching the Super Bowl wondering just this:

Will the Patriots cover the spread? And why did I bet the coin flip would be heads when I knew all along it would come up tails?