Rock of Gibraltar will play the percentages.

Europe's leading racehorse had been entered in two Breeders' Cup races, the Mile and the Classic, and trainer Aidan O'Brien had to choose between a safe bet and a high-stakes gamble. Rock of Gibraltar would be a heavy favorite running on the turf in the Mile, the distance that is his specialty. The Classic, at 11/4 miles on dirt, would be unknown territory, but a victory would propel his reputation (and stud fee) into the stratosphere.

In a decision watched closely by rival trainers as well as bettors, Rock of Gibraltar's management opted to run in the Mile on Saturday at Arlington Park.

Mike Dillon, racing manager for the colt's co-owner, explained, "He has a turf pedigree, and we decided we should stick with the race that he knew." He dismissed the argument that the colt didn't have much to prove by winning another turf race at his favorite distance. "He has a lot to gain if he can come to America and beat America's best," Dillon said.

Rock of Gibraltar drew post 10 in the 14-horse field, and was established as the even-money favorite by oddsmaker Mike Battaglia.

O'Brien opted to run Hawk Wing (who also had been entered in two races) in the Classic. Although Hawk Wing, like his stablemate, has done all of his racing on grass, he appears better bred for dirt than his stablemate. He was listed at 5 to 1 in a race in which three U.S. 3-year-olds -- War Emblem, Medaglia d'Oro and Came Home -- are the top choices.

With the large fields in most Breeders' Cup races, the post-position draw assumes a far greater importance than it does for most racing events. An outside draw in a race with a short run to the first turn can be fatal.

The Maryland-based 2-year-old Toccet, who won the Champagne Stakes at Belmont Park in his last start, was one of the unluckiest horses in this morning's draw, getting post position 14 in the Juvenile. Since the race starts near the first turn, he can't avoid being parked wide.

The Mile also has a short run to the turn, and while Rock of Gibraltar didn't get an ideal spot, his well-regarded stablemate Landseer was even less fortunate.

The winner of the Keeneland Turf Mile in his last start, Landseer will break from post 13.