Although there are a few mounts still open, the jockey assignments for the Breeders' Cup World Thoroughbred Championships are pretty much confirmed. Of the leading riders, Mike Smith, Jerry Bailey, Pat Day, and Edgar Prado are particularly deep in talent.Smith, who is the only jockey ever to have won six different Breeders' Cup races, has made a remarkable comeback since moving his tack to California, and is well stocked in talent, riding in six of the eight races. Bailey, who is never wanting when it comes to Breeders' Cup mounts, has been named on seven live horses, as has Prado. Speaking of comebacks, Pat Valenzuela, who has returned from his substance abuse battle in dramatic style, also is named on seven horses.Smith will be on four leading contenders -- Azeri in the Distaff, Came Home in the Classic, Vindication in the Juvenile, and Composure in the Juvenile Fillies, the last two for trainer Bob Baffert. He also rides The Tin Man, winner of the grade I Clement Hirsch Memorial in his last start, and Kalookan Queen, who defeated colts in the grade I Ancient Title BC Handicap. Bailey, who is tied with Day for most Breeders' Cup victories with12, not only has seven mounts, but everyone of them has a legitimate shot to win. He rides Medaglia d'Oro in the Classic, Imperial Gesture in the Distaff, Orientate in the Sprint, Beat Hollow in the Mile, Banks Hill in the Filly & Mare Turf, Bull Market in the Juvenile, and Santa Catarina in the Juvenile Fillies.Day's six mounts are Farda Amiga in the Distaff, With Anticipation in the Turf, Good Journey in the Mile, Dollar Bill in the Classic, Whywhywhy in the Juvenile, and Day Trader in the Sprint.Prado, who captured his first classic this year, winning the Belmont Stakes on Sarava, will ride Milwaukee Brew in the Classic, Take Charge Lady in the Spinster, Sky Mesa in the Juvenile, Denon in the Turf, Landseer in the Mile, Owsley in the Filly & Mare Turf, and Thunderello in the Sprint.John Velazquez also is well stocked with Storm Flag Flying in the Juvenile Fillies, Harlan's Holiday in the Classic, Summer Colony in the Distaff, Carson Hollow in the Sprint, and Starine in the Filly & Mare Turf. He also will ride one of Aidan O'Brien's horses in the Juvenile. With first-call rider Mick Kinane expected to choose Hold That Tiger, Velazquez could wind up on the $6.4 million yearling Van Nistelrooy.Valenzuela's best chance will be on Golden Apples in the Filly & Mare Turf. He also rides Falcon Flight in the Turf, Starrer in the Distaff, Most Feared in the Juvenile, Crafty C.T. in the Sprint, Sea Jewel in the Juvenile Fillies, and Del Mar Show in the Mile. Del Mar Show is owned by Allen Paulson Living Trust, and Valenzuela has already won Breeders' Cup races on Paulson Family horses Arazi, Fraise, Eliza, and Opening Verse.Jorge Chavez, who scored both his Breeders' Cup victories in 1999, has only four mounts firmed up, but agent Ronnie Ebanks still is working on landing one or two more. Chavez is named on Toccet in the Juvenile, Aldebaran in the Mile, E Dubai in the Classic, and Kazzia in the Filly & Mare Turf, the last two for Godolphin.Jose Santos, who has been riding in top form, will be aboard Mandy's Gold in the Distaff, Volponi in the Classic, and Blazing Fury in the Turf, with a couple of other possibilities that haven't been finalized yet. Santos has six Breeders' Cup victories to his credit.Corey Nakatani, with five Breeders' Cup victories, will be aboard Momentum in the Classic, and Swept Overboard in the Sprint. He has already won the latter twice with deep closers like Swept Overboard. There is a possibility that he also will be on Forbidden Apple in the Mile and Voodoo Dancer in the Filly & Mare Turf, both for Christophe Clement.Victor Espinoza, who burst into the national spotlight in this year's Triple Crown, will ride his Kentucky Derby and Preakness winner War Emblem in the Classic, as well as Kafwain in the Juvenile, Disturbingthepeace in the Sprint, and Atlantic Ocean in the Juvenile Fillies. Other than in the Sprint, he will be seen only in the colors of the late Prince Ahmed Salman's The Thoroughbred Corp.Kent Desormeaux, winner of two Breeders' Cup winners, will be aboard Ballingarry in the Turf, Dublino in the Filly & Mare Turf, and Touch of the Blues in the Mile. He also may land the mount on d'Wildcat in the Sprint.Gary Stevens, who has won eight Breeders' Cup races, will ride Macho Uno in the Classic, Zavata in the Juvenile, and Nuclear Debate in the Mile. He also is a possibile rider for Voodoo Dancer in the Filly & Mare Turf.