The 2020 older-dirt male champion Improbable, a Grade 1 winner at 2 and 4 who stood at WinStar Farm in Versailles, Ky., died Saturday night at Rood & Riddle Equine in Lexington, Ky., where he was being treated for the muscle disorder ataxia.

Improbable, who was 8, will have his first sire crop on the racetrack this year.

Improbable burst on the scene in 2018, winning his first three career races for Hall of Fame trainer Bob Baffert, including the first of four career Grade 1 victories in the Los Alamitos Futurity.

His 3-year-old season was lackluster by the standards he set in his other two years on the track, winning just the Shared Belief Stakes at Del Mar, although he did finish fourth in the Kentucky Derby and sixth in the Preakness in 2019.

His 4-year-old season was by far his best as the City Zip colt reeled off consecutive Grade 1 wins in the Santa Anita Gold Cup, Whitney and Awesome Again before finishing second in his final race to stablemate and eventual horse of the year Authentic in the 2020 Breeders’ Cup Classic at Keeneland.