Quadratic, the sire of 25 stakes winners, died Oct. 24 at Morgan Kenyon's Deer Haven Farm near Keysville, Va. He was 30. The son of Quadrangle had been at Deer Haven the past four years.Quadratic was bred in Maryland by Ryehill Farm owner Jim Ryan and raced for Ryan and August Belmont IV. He won five stakes during his 19-start career including the 1977 Cowdin Stakes (gr. II). At three, he ran second or third in six graded stakes, retiring with six wins from 19 starts and earnings of $233,941. He missed the Triple Crown races due to a knee injury.Quadratic began his stallion career in 1979 at Blue Ridge Farm near Upperville, Va., and moved to Claiborne Farm in Kentucky in 1982. He moved to Meadowville Farm in Virginia in 1990.Among Quadratic's stakes winners are Super Derby (gr. I) winner Home At Last and Monmouth Oaks (gr. II) winner Quixotic Lady.Quadratic is out of Broodmare of the Year Smartaire, by Quibu. Smartaire is also the dam of champion filly Smart Angle (by Quadrangle), graded stakes winner Smarten, and stakes winner Smart Heiress.