Group I winner One Cool Cat, the highest-priced U.S. auction yearling of 2002, has been retired from racing after suffering a condylar fracture of a hind leg during a Sept 29 workout at Ballydoyle in Ireland. The prognosis following an operation that afternoon is "very good," according to Irish-based Coolmore Stud.One Cool Cat, by Storm Cat, won four Irish stakes for Sue Magnier, whose husband, John, is managing partner of Coolmore, and Coolmore associate Michael Tabor. Another Coolmore associate, Demi O'Byrne, bought One Cool Cat for $3.1 million at the Keeneland July yearling sale from Taylor Made Sales Agency, agent.Bred in Kentucky by WinStar Farm, One Cool Cat captured the Independent Waterford Wedgwood Phoenix (Ire-I), Dunnes Stores National (Ire-I), and Dubai Duty Free Anglesey (Ire-III) Stakes as a 2-year-old and the Patrick P. O'Leary Memorial Phoenix Sprint Stakes (Ire-III) at three. An English winner, he ran third in this year's Victor Chandler Nunthorpe Stakes (Eng-I).One Cool Cat's dam, Tacha (by Mr. Prospector), is out of grade II winner Savannah Dancer. No decision has been reached as to whether One Cool Cat will stand at Coolmore or at its North American satellite, Ashford Stud, near Versailles, Ky. One Cool Cat concluded his racing career with five wins from 10 starts and earnings of $568,086.