There are just five entrants in Saturday&rsquo;s Group 1 King George VI and Queen Elizabeth Stakes at Ascot in England, but the race is a dandy, with two champions, Workforce and St. Nicholas Abbey, opposed by Rewilding and the dangerous 3-year-old Nathaniel. The fifth horse is Debussy, who won the 2010 Arlington Million but has shown little so far in 2011.\r\nBREEDERS' CUP&nbsp;CHALLENGE: Racing schedule, replays, and past winners &raquo;\r\nIt was in the 2010 King George that the bloom briefly came off Workforce&rsquo;s rose. Fresh off a dominant victory in the Epsom Derby, Workforce turned in a shocking fifth-place finish in this race last summer, though Workforce validated his high quality by winning the Arc the next time he raced.\r\nThe King George is a Breeders&rsquo; Cup Challenge race, offering the winner a fees-paid berth in this fall&rsquo;s Breeders&rsquo; Cup Turf at Churchill Downs.\r\nWorkforce&rsquo;s connections might well have passed this King George had rain not recently softened the Ascot course. Workforce prefers give in the ground, and fairly quick, firm going at Sandown might have contributed to his last-out, half-length defeat at the hands of So You Think in the 1 1/4-mile Eclipse Stakes. Neither course condition nor distance will provide an excuse Saturday, and Workforce deserves to be favored.\r\nTrainer Aidan O&rsquo;Brien got the better of Workforce with So You Think and will attempt to take the Michael Stoute-trained horse down again with St. Nicholas Abbey. A champion 2-year-old in 2009, St. Nicholas Abbey raced just once last year, finishing unplaced, but has come back into form again this season. He won a Group 3 at Chester in May and then defeated the fine mare Midday last out in the Coronation Cup over 1 1/2 miles at Epsom. O&rsquo;Brien&rsquo;s son, Joseph, has been given the mount in the King George.\r\nGodolphin&rsquo;s Rewilding is working on a perfect 2011, with impressive wins this year in the Sheema Classic on Dubai World Cup Night and a surprising upset of So You Think in the Prince of Wales&rsquo;s Stakes at Royal Ascot. Trained by Mahmood al Zarooni, Rewilding has a big late run that seems equally effective at 10 and 12 furlongs.\r\nNathaniel steps up to face older rivals for the first time, but appears to be a lightly raced horse with upside for trainer John Gosden. Nathaniel lost the May 5 Chester Vase by a head to Treasure Beach, who returned to just miss in the English Derby before capturing the Irish Derby. Gosden held Nathanial out of the Derby, instead sending him out to easily win the Group 2 King Edward over 1 1/2 miles at Ascot last month. Debussy, another Gosden horse, has shown little in his last three starts and may be out for a test drive in preparation for a possible return trip to Arlington.