When he came up for auction at a 1975 summer sale of Kentucky yearlings, he was just Hip No. 128, an anonymous colt with an awkward bearing and a slightly skewed front foot. He was gaveled off at the paltry price, by thoroughbred standards, of $17,500, and led away to his new owners, Karen and Mickey Taylor. It seemed hardly an auspicious union—an unassuming yearling and a stable whose racing silks were just two years and a handful of horses old.
The Taylors bid for the big dark bay on the advice of a friend,...