Bill Hartack won the Kentucky Derby five times, and seemed to hate every moment. "If only Bill could have gotten along with people the way he got along with horses," a trainer said. His impoverished upbringing didn't help: his mother was killed in an automobile accident; the family home burned down; his father was murdered by a girlfriend; and he was estranged from his sisters for most of his life. Larry King, his friend, said it was just as well...