Sid is a former champion steeplechase jockey whose hand was so badly injured in a racing accident that he had to give up riding. He becomes a private investigator with the Hunt Radnor associates in Odds Against, but does little work for them until his father-in-law jolts him from his depression and dangles and interesting case in front of him. In later books he has his own agency, and specializes in racing inquiries.
Books:
Odds Against,
Whip Hand,
Come to Grief,
Under Orders