The 28th Breeders' Cup Championshipsget underway tomorrow afternoon at Churchill Downs. The event includes 15 races over two days, featuring some of the world’s top thoroughbred champions.Breeders’ Cup President Craig Fravel says one of this year’s big story lines is the return of Goldikova, the six year old Irish mare seeking a fourth straight Cup victory."We actually moved the Mile turf race to the second to last race on the card immediately preceding the Classic this year. We think that’s one hell of a double to end the race card and we’ll highlight just how special this effort by Goldikova is," Fravel said.In the final race---the Classic—the early favorite is Uncle Mo, who was the morning line favorite in last year’s Kentucky Derby before he was scratched due to illness.The 2011 Breeders’ Cup is expected to have an economic impact of more than $50 million on the Louisville area.(Photo of Goldikova from Facebook)