By Joe McGinniss. Simon & Schuster. 263 pp. $22.95 If you want to know why Joe McGinniss -- the author, most famously, of a true-crime bestseller, Fatal Vison -- bothered to write a book about horse racing, he's happy to tell you -- he read Laura Hillenbrand's book, Seabiscuit, and felt two urges revive. "It had been four years since I'd last published a book, and thirty-two years since I'd gone to Saratoga with the intention of writing a book about a racing season there. I had no idea whom or what I might find, but I decided it was time to go back." Fortunately for the reader, when he got there in the summer of 2003, he found P.G. Johnson, Racing Hall of Fame trainer of Volponi, who won the Breeders' Cup Classic in 2002. Johnson is an authentic "character" of the Damon Runyan sort, a horse trainer so steeped in the life, history and ways of the racetrack that everything he says and does is idiosyncratic as well as fascinating.

Horse racing is fun to write about, but books about horse racing are generally of two kinds: Either the scrappy trainer, owner, horse or jockey succeeds in winning the big race (a la Seabiscuit), in which case hard work and authenticity are rewarded, or the scrappy trainer, owner, horse and jockey do not succeed, in which case horse racing turns out to be a mugg's game after all (but colorful all the same). When McGinniss showed up at Saratoga last July, he didn't know which kind of book he was going to be writing, but he managed to double his bet by tangentially including Barclay Tagg, P.G. Johnson's friend and the trainer of Funny Cide, the New York-bred gelding who won the 2003 Kentucky Derby and Preakness Stakes. Both Johnson and Tagg were looking for big wins at Saratoga, to vindicate their horses' victories in big races and, perhaps, to vindicate their own methods and horsemanship.

If there is a track that redeems the long shady enterprise of horseracing in America, for McGinniss it is Saratoga, located not far from Albany in Saratoga Springs, "a peaceful old town of twenty-five thousand." Racing is popular at Saratoga. By contrast, elsewhere in the United States, "from Aqueduct to Hollywood Park, from Arlington to the Fair Grounds in New Orleans, people were staying away from racetracks in droves." McGinniss rented a house for the season for $8,000 and started hanging around the track in the mornings, but it was not fun. It rained and it rained, and it rained some more.

P.G. Johnson, Barclay Tagg and their other friend, Allen Jerkens, quickly acquired an antagonist, Bobby Frankel, the hugely successful stakes-winning trainer -- a onetime New Yorker but now a Californian -- who brought some good horses to Saratoga to run against the hometown talent. As soon as he introduces Frankel, McGinniss recycles rumors about him: that he originally left New York pursued by rumors (rumors about rumors being especially damning) and that his horses do suspicious things (like speed up suddenly in the last eighth of a mile). Since he needs this antagonist to add life to his book, McGinniss doesn't bother to note that in spite of all the talk, and a dour personality, Frankel has as many supporters as detractors in the racing world, who attribute his skill to talent and good horses, not to anything underhanded.

McGinniss made a better authorial choice in interspersing his narrative with Johnson's, which is also told in the first person. Johnson is, by his own testimony, too crusty and outspoken for his own good. His racing stable is full of cheap horses because he doesn't flatter owners or court them -- he prefers them to stay home and keep out of his way. (Barclay Tagg, too, is evidently discommoded by his riotous crew, the famous group of former high-school friends known as Sackatoga Stable, who brought a carnival atmosphere to Funny Cide's bid for immortality in 2003.) Johnson's chapters are a bit short, and it takes a while for him to get rolling, but as the book and the season progress, it becomes evident that he does have lots of stories to tell, and the only pity is that, owing to a throat condition, it is so difficult for him to tell them. Johnson is actually quite funny, but his delivery is dry and cranky. By the end of the book, he has become (God forbid) as appealing to McGinniss, and to the reader, as he is to his close-knit family.

Unfortunately for Johnson and Tagg, The Big Horse turns out to be the second kind of racing book. Neither Funny Cide nor Volponi lived up to his promise. Even Frankel did not have a very good year. As for McGinniss, his six rainy weeks at Saratoga were followed by an alternative hell -- heat, glare and despair -- in southern California. McGinniss mentions several times that he is 60 now, and so The Big Horse is really a meditation about aging and decline. Not only are McGinniss and Johnson older, sadder and more cynical than they were in the great days of the '70s; not only is Santa Anita, the site of the Breeder's Cup race where Volponi and Funny Cide ran last and second to last in the Classic, surrounded by fires (the worst in decades, according to McGinniss): Horse racing itself isn't what it was. The horses are more fragile, and racing is less fun, corrupted by corporate-style trainers and sacrificed for the sake of big sales at the yearling auctions by the breeders. The fans are, literally, a dying breed.

Well, yes. And no. The Big Horse is a pretty standard horse racing book, moody and detailed, hastily done and not very original. In spite of himself, McGinniss shows that the world of horse racing is still rich in material, much the same as it has been for hundreds of years now, a gathering place for eccentrics and misanthropes and wishful thinkers that turns out characters by the carload. *

Jane Smiley is the author of "Horse Heaven" and "A Year at the Races."