In the following excerpt, Morris draws parallels between author Hillenbrand, a sufferer of Chronic Fatigue Syndrome, and the against-all-odds champion she chronicled.

The best-selling American sports book of the year 2001—and one of the year's bestsellers in any genre—is Seabiscuit: An American Legend by Laura Hillenbrand. The success of the book is as unlikely as the success of Seabiscuit himself. How does a book about a half-century-dead racehorse become a publishing sensation? Sales of the book don't depend much on nostalgia, since most Americans are too young to have seen Seabiscuit race. Nor is Thoroughbred racing the cynosure of media attention that it was when Seabiscuit briefly dominated the sport in the 1930s. One can barely imagine selling such a book to a publisher in 2001, let alone to hundreds of thousands of readers.

But the Biscuit always beat the odds. Overmatched at ages two and three...