O'Brien eyes Kempton prize Aidan O'Brien today revealed three possible challengers for the inaugural Kentucky Derby Challenge Stakes at Kempton on March 18th. A guaranteed spot in the Kentucky Derby itself is on offer to the winner, as well as a 100,000 bonus if they make it to Churchill Downs at the start of May. Kempton are planning an American theme to the occasion and will offer free entry for the public. O'Brien was the last European trainer to have a Kentucky Derby runner when Johannesburg and Castle Gandolfo lined up to little effect in 2002. He said: "We have three possibilities for at this stage - Born To Be King, Chief Lone Eagle and Great Wisdom. "It's a great initiative on Kempton's part and the fact that the winner is guaranteed a spot in the Kentucky Derby is a major bonus." Kempton report so much interest from leading trainers that they may have to ballot horses out of the race. Brian Clifford, Kempton's director of racing, said: "Initially, trainers have really embraced the contest. "We had been thinking about November for the race but Aidan, John and others said if we make it in March they will be able to get their better horses ready. "John Gosden has four possibilities and hopes to run two, Paul Cole could run two, we hope Aidan may send us two across from Ireland and Richard Hannon is interested. "We may not even have the space for all of them in the field of 14. "I wouldn't rule (balloting) out. The dream is to go from here to the Kentucky Derby and run a good race there." There will be no Group One penalties in the nine-furlong Polytrack conditions event, which will be held at 7.50pm on a Wednesday evening.