Clock Stopper, who won the April 16 Commonwealth Breeders' Cup Stakes (gr. II) at Keeneland, was retired following the discovery of a bowed tendon in his left front leg following the race.Bred in Kentucky by Dr. Lance Bell and David Hochberg, Clock Stopper won six of 20 starts and earned $779,524 for the Young family's Overbrook Farm and trainer Dallas Stewart. The 5-year-old gelded son of Gilded Time captured only one other stakes in his career, the Perryville Stakes at Keeneland as a 3-year-old.He also placed in eight stakes, seven of which were graded. Those efforts included the Forego Handicap (gr. I) and Frank J. De Francis Memorial Dash Stakes (gr. I).Clock Stopper, who was produced from the Farma Way mare Great Fun, is under the care of Overbrook veterinarian Robert Copelan at Sunnyside Farm near Paris, Ky. Copelan owns the farm with Jeff Thornbury.