Blue Grass of Kentucky plot
Major Randolph McIvor has a son, Lin, who helps train his horses and another, Sandy, who rides them. Their stable has struggled, but they are preparing their promising new thoroughbreds Encino and Tarzana for the Kentucky Derby. Lin is in love with James B. Armistead's daughter Pat, though her wealth intimidates him. Armistead has a star horse named Blue Grass who will be competing for 1st place in the derby. What no one knows except Pat is that Blue Grass' sire was a different horse than originally intended. A trainer, Layton, makes a formal complaint after Blue Grass won the Derby, claiming the winner's pedigree cannot be proven.