Pomona Fairgrounds, 1956. Abandoning his hopes of becoming an attorney, Gary Biszantz was going home to try to turn round his father's automobile dealership in Los Angeles. He broke his journey at a horse sale, having loved Thoroughbreds since being taken racing as a kid, when he would stand on a chair and marvel at "the epitome of strength, speed, skill and style." "And the guy next to me puts up his hand at $400 and the auctioneer says: 'Sold!'" Biszantz recalls. "The guy looks at me and says, 'Would...