(ABC News) -- Gamblers are betting what could be a record amount of money on Super Bowl XLVII. It's still too early to predict exactly how much money will be riding on the line, come February 3, but experts say the total being wagered in Las Vegas alone could approach the all-time Super Bowl record--$94.9 million—set back in 2006.
"It's an intriguing match up because the coaches are brothers," says Jay Kornegay, vice president of Las Vegas' Superbook, the world's largest race and sports betting book. "The Ravens, the hottest team, may not have a large fan base, but they certainly add an intriguing element. There's the fact Ray Lewis is retiring. It's one of the better teams versus the hottest team."
It's hard to predict how much money ultimately will be bet, says Jay Kornegay, because about 80 percent of all wagers get made in the last few days before the game. Still, he says, he's expecting this year's Super Bowl to come very close to the record—probably between $92 million and $93 million.
And that figure, he says, represents "a drop in the bucket" compared to total U.S. betting on the outcome, almost all of which is illegal. The only legal place to place a Super Bowl bet in the U.S. is Nevada, though New Jersey is working to legalize sports betting at its 12 Atlantic City casinos despite a federal ban.
The line in Las Vegas right now, he says, has the 49ers a 4-point favorite. That will likely change as the bookmakers attempt to even out the betting before game time.
As in past Super Bowls, so-called proposition bets—wagers on such specific things as how big the point spread will be, how many touchdown passes will be thrown by a given player, or whether either team will score in the first 5 ½ minutes—are extremely popular, and can represent, Kornegay says, anywhere from 10 percent to as much as 50 percent of total betting on the game.
Although Superbook will eventually offer 20 pages of such betting possibilities—some 300 in all-- Nevada bookies are restricted to offering only those propositions whose outcome can be documented on the field of play. So, for instance, Superbook cannot take bets on how long it will take Alicia Keys to sing the National Anthem.
"Nobody keeps track of that," explains Kornegay. Moreover, there's no way to time it precisely: What if Alicia warms up with a little humming first? "In the state of Nevada," he says with audible regret, "We can't take the real crazy ones."
Bookies in the United Kingdom, however, labor under no such impediment.
Jessica Bridge, a spokesperson for Ladbrokes, the biggest bookmaker in the U.K., says they are offering all kinds of imaginative proposition bets. Example? They are offering odds of 10 to 1 that Beyonce will suffer what Bridge calls "a Janet Jackson" incident (nipple slippage, wardrobe malfunction, call it what you will). You also can bet on the likelihood that one of the Harbaugh brothers punches out the other (100 to 1) or sprays either Champagne or some other liquid in the other's face (20 to 1).
These and other sibling-related possibilities make up what Ladbrokes calls its "Brotherly Love Special" portfolio of proposition bets.
Ladbrokes has the 49ers as the favorite, with odds of 4 to 7. "So, if you place a $10 bet, you get back $15.71. You don't exactly become a millionaire. That's how sure we are they'll win." Bet on the Ravens, and Ladbroke gives you odds of 6 to 4: Bet $10, and, if you win, you get $23.50.