The Walter Mittyish flirtation of Paris Review editor Plimpton with pro sports (Shadow Box: boxing; Paper Lion: football; Open Net: hockey) now extends into his first novel. But despite its winsome premise--a Buddhist monk storming baseball's Major Leagues with a 168-mph fastball--this fluffy tale, puffed up from a story Plimpton wrote for Sports Illustrated, is more a towering pop fly than a home run. Narrator here is Bob Temple, a once-hot reporter suffering from writer's block induced by Vietnam War horrors. Retired to Florida. Bob is invited one spring to cruise in tire Goodyear blimp along with Frank Cashen, Nelson Doubleday, and other real-life N.Y. Mets officials. Aloft. Bob enjoys tire odd spectacle of the men dropping balls to Met catchers 1000 feet below. Days later, Cashen summons Bob and fills him in: Sidd Finch, an English orphan and graduate of years of Tibetan Buddhist Raining, is arriving at the Mets' camp with a pitch 50% faster than any previously thrown. At the Mets' request, Sidd and his new girlfriend Debbie Sue move in with Bob; but it's only after a lot of digressive talk about Sidd's days in Tibet, some novel trivia about past pitching greats, and the appearance in (where else?) Sports Illustrated of an article about Sidd written by (who else?) one George Plimpton that Bob finally sees Sidd pitch. He's that fast, but so wild as to skip town, scared of killing someone. But when the new season begins, Sidd returns to pitch the most perfect game ever pitched; then after some silly filler plotting involving two Mafiosa and Sidd's abilities at mimicry, Sidd pitches most of a second most perfect game ever pitched--only to leave the game, N.Y., and the novel one out away from victory, when his control falters. But never mind; Bob's now lost his writer's block and sits down to write this tale. . . Plimpton starts strong, with charming characters and that nifty premise: but charm soon devolves into cute and the plot into a talky pastiche. Still, full of enough lore to please baseball fans--although others should head out to the ballpark instead.