When the best seller "Seabiscuit: An American Legend" was being made into a movie, readers who loved Laura Hillenbrand's book and people who love horse racing had reason to be apprehensive. Depictions of the sport on the screen are typically cliched, inaccurate or mawkish. Even a TV series with the gritty realism of "The Sopranos" filled a racing subplot with a succession of absurdities.

The movie "Seabiscuit," which opens today at theaters across the country, didn't avoid all potential pitfalls. Director and writer Gary Ross occasionally sought dramatic impact at the expense of accuracy or plausibility. Nevertheless, the film ought to delight hard-core racing fans as well as general audiences. Visually, it is marvelous, and its racing sequences are grippingly realistic. But its greatest asset, of course, is the true story of Seabiscuit. His improbable success made him a national hero during the Depression, and Hillenbrand's book has already enthralled countless readers who had no prior interest in horse racing.

Ross accomplished the difficult task of bringing together the disparate stories of three people -- owner Charles Howard, jockey Red Pollard and trainer Tom Smith -- whose lives intersected with Seabiscuit. To racing fans who read the book and understand the central role of the trainer in almost any horse's development, Smith was the most intriguing character. Hillenbrand brought him to life in her most memorable passages: "He talked to virtually no one but his horses, and then only in their vernacular of small gestures and soft sounds. . . . People merely brushed up against him. Only the horses seemed to know him well."

But a character whose chief trait is taciturnity -- he was known as "Silent Tom" -- doesn't make a good focus for a popular movie, even with the superb Chris Cooper playing him. So Howard (Jeff Bridges) and, especially, Pollard (Tobey Maguire) are the central figures in the film. Although I am dubious of the proposition that any horse's success may be due to a magical affinity between him and his rider, Hillenbrand tells the Seabiscuit story this way and Pollard's relationship with the horse gives the movie much of its appeal. When the struggling rider starts working with the horse who has been adjudged a total failure, and the two of them transform each other's lives, the portrayal of their relationship is touching without seeming sappy.

The racing sequences in "Seabiscuit" are vivid and believable -- a result, surely, of the involvement of Hall of Famers Chris McCarron, who served as technical adviser, and Gary Stevens, who played jockey George Woolf. When the young Pollard is competing at a bush track, the race is filled with jostling, shoving and dirty tricks. The famous match race between Seabiscuit and War Admiral -- with Woolf subbing for the injured Pollard -- is as realistic as the old, grainy race films themselves.

Ross did take liberties with the historical facts of Seabiscuit's career. The movie shows Pollard getting hurt virtually on the eve of the match race, but the injury occurred months before. In the movie he makes his comeback just in time to ride the Santa Anita Handicap, while in reality he had ridden Seabiscuit in three prep races. The depiction of that Santa Anita Handicap bears not even a faint resemblance to the way the race was run. These alterations constitute acceptable poetic license, but the Santa Anita Handicap nevertheless is the one unfortunate part of the film.

Woolf is on one of Seabiscuit's rivals, and in the starting gate he hollers to Pollard to inform him that he's riding in the race, too, but he doesn't think he can win -- an absurd moment. Seabiscuit trails the field in the early running, but as he rallies, Pollard pulls alongside Woolf and they have a brief mid-race chat, with Woolf wishing him luck. It was the kind of preposterous departure from plausibility that the movie had avoided till the final scene.

The thoroughbred racing industry hopes that the excitement and publicity surrounding "Seabiscuit" will stimulate a resurgence of interest in the sport, and this might indeed happen. (Judging from the interest in this year's Belmont Stakes and the stunning size of the television audience, an upsurge may have begun already.) For even if critics may quibble with some elements of "Seabiscuit," the film's depiction of the racing world rang true and captured the elements that make the sport so appealing. The athletes are magnificent; the competition is a mesmerizing visual spectacle; the people involved the game are fascinating, diverse and, in most cases, genuine; and the sport has the power to stir strong emotions. Now the industry needs to remind people that these virtues are just as present in modern racing as they were in Seabiscuit's era.