AmericanPharoah is the 5-2 favorite, followed closely by Dortmund at 7-2, as of Friday morning. Frosted is next at 7-1, followed by Carpe Diem and Firing Line, both at 10-1.
AmericanPharoah has been the favorite to win the Derby since September in Las Vegas. John Avello, executive director at the Wynn race and sportsbook, opened American Pharoah at 40-1 on Sept. 15.
AmericanPharoah has won four of five races entered, including an impressive showing at the Arkansas Derby. AmericanPharoah is Avello's biggest liability in his futures book.
"I've taken some big bets on him at 3-1 and 7-2," Avello said. "Good, solid four-figure bets."
Dortmund, the other top-tier contender in Baffert's powerful one-two punch, is undefeated in six races and is a bigger threat to some Las Vegas sportsbooks than AmericanPharoah.
At William Hill, Dortmund attracted 32 percent of all money bet on the Kentucky Derby futures book, including a $2,500 wager at 8-1 placed on March 15. That's nearly double the amount of money that was placed on AmericanPharoah at William Hill, before the future book was closed prior to post positions being released. A Dortmund victory would cost the William Hill book a six-figure loss, according to director of marketing Michael Grodsky.
Bettors also are backing Dortmund to finish ahead of AmericanPharoah in an individual matchup prop bet at sportsbook operator CG Technology. Baffert, who has trained three Kentucky Derby winners, has never raced his two stars.
"We took a couple sophisticated gets on Dortmund to beat AmericanPharoah," said Jason Simbal, CG Technology vice president of race and sports.
The Kentucky Derby is slated to start at 6:24 p.m. ET, kicking off what will be a raucous Saturday at Churchill Downs and in Las Vegas. Game 7 of theLos Angeles Clippers-San Antonio Spursplayoff series tips at 8 p.m., followed by the Floyd Mayweather-Manny Pacquiao blockbuster fight.
A record $133.07 million was bet on the Kentucky Derby in 2012 nationwide. The betting handle has been on the decline the past two years, dropping to a three-year low of $129.15 million last year, according to KentuckyDerby.com.
Vegas bookmakers hope the surrounding events will help produce a boost in Derby handle.
"I think the Derby is going to get a little benefit from the fight," said Jay Rood, vice president of MGM race and sports. "Derby handle has sort of been on the decline and horse racing in general is not prospering by any stretch of the mean."
American Pharoah and Dortmund the favorites for Kentucky Derby
Jeannine Edwards speaks with Bob Baffert, the trainer of both American Pharaoh and Dortmund, as he looks to win his fourth career Kentucky Derby as a trainer.