The Kentucky Wildcats' dominating start to the college basketball season has one Nevada sportsbook in a precarious position.

In July, a customer at the William Hill sportsbook requested odds on Kentucky going undefeated. The book obliged and gave coach John Calipari's team a 50-to-1 chance to win every game, including the NCAA tournament. Five months later, the top-ranked Wildcats are 13-0 and William Hill is staring at a six-figure liability that keeps growing.

"It's pretty good six figures, too," William Hill director of trading Nick Bogdanovich said of the liability on the popular prop bet. "They keep betting it."

Kentucky defeated No. 4 Louisville 58-50 on the road Saturday, the Cardinals being the biggest challenge remaining on the Wildcats' regular-season schedule. They're expected to be solid favorites in their remaining 18 games and are outright favorites to win the national championship at multiple Vegas sportsbooks. But Kentucky is still an underdog to complete the first undefeated season since the 1975-76 Indiana Hoosiers.

Entering the week, William Hill has Kentucky at plus-450 to run the table. You can bet "No," Kentucky doesn't finish undefeated at minus-650, meaning you'd have to wager $650 to win $100. Before the Louisville game, 95 percent of wagers were on "Yes."

William Hill took 39 bets on the Wildcats going undefeated at 50-1 odds. The biggest bet at that price was $500, which would produce a $25,000 payday if Kentucky runs the table. Bogdanovich said he's taken several four-figure bets on the prop as the odds have shrunk.

At the Westgate SuperBook, Kentucky is a 4-5 favorite to win the national championship. It's rare to have a team listed as an outright favorite this early in the season.

"It's been a long time since that's happened," SuperBook oddsmaker Ed Salmons said.

At the MGM sportsbook, Nevada's largest book, Kentucky has attracted nearly double the number of bets to win the national championship than any other team.

"Arizona, Duke and Wisconsin are next, but Kentucky has more than double than most of those teams," Jay Rood, VP of MGM Race and Sports, said.

Salmons and Bogdanovich both have Duke second in their power ratings and project the Blue Devils would be "4-6-point" underdogs against Kentucky.

Kentucky opens its 18-game Southeastern Conference schedule Jan. 6 at home against Mississippi. Calipari is sticking to the moment, and not what people are saying his program can accomplish over the long haul.

"They picked the Germans in World War II also. Look, the good news is we have another break," Calipari told reporters after beating Louisville. "We have [time] to get my team right. We have to put in a different zone because we're going to face some different things. I want to put in a different rotating press. I want to do some different things offensively to try, because we have time."