Secretariat is arguably "the greatest all-time American thoroughbred," and turf editor Capps's devotion makes him the voice to call the race. His is probably not, on the other hand, the voice to bring the "Big Red colt's" legend alive for casual readers. Capps's thralldom to Secretariat started two generations back in Meadow Stable's bloodlines, with Secretariat's sire, Bold Ruler and his sire, Nasrullah. Secretariat is always physically present, but the successive trainers and stable managers and jockeys in this legend are only racing diary entries. Capps (Spectacular Bid, also in this series of "Thoroughbred Legends") re-creates some of Secretariat's best races (including a record-breaking under-two minute Derby run). He lays on the kind of statistical detail, stable gossip and racetrack argot that fans love, borrowing text excerpts from every major racing journal, and a corny horseman's poems. His best moment of exposition comes after the 1973 Triple Crown Belmont run: "They were cheering the most incredible two-and-half minutes in American racing history.... Secretariat was no longer a rarity among thoroughbreds. He was singular." The casual monotone of most of Capps's account stems from not solving the "replay problem" inherent in any sports drama. Despite Capps's digressions into thoroughbred culture, including the origins of the Triple Crown, he does offer a detailed history on Secretariat—including 16 handsome pages of photographs. (Mar.)