The ""movie brats"" of the title are a core of six young movie-weaned filmmakers--Francis Coppola, George Lucas, Brian DePalma, John Milius, Martin Scorsese, Steven Spielberg--who share film school or buff backgrounds, commercial ideas, and the clout to make films (The Godfather, Star Wars, Jaws, etc.) ""more successful than any other in history."" Unfortunately, the lengthy introduction and the chapters devoted to each of the six are all colored by the authors' weak thesis that the postwar growth of American suburbs killed the ""old"" Hollywood and spawned the ""new."" (Steven Spielberg's Close Encounters of the Third Kind is said, for example, to ""encapsulate the death of suburban ideals."") Neither does it make sense to say that, at the end of 1977, men like Coppola and Scorsese stood ""unchallenged as the powers within a new Hollywood."" Yet the authors' knowledge of film history, their manifest intelligence, and clear, lively writing together claim attention. They reexamine why, after the stellar year of 1946, the movie business declined in the Fifties and Sixties and came back to life in the Seventies. (The 1971 sanctioning of films as tax shelters, they point out, provided financing for independent productions.) Their chapters on the filmmakers interweave industry talk, interviews with directors and moguls, and provocative--often lengthy--analyses of the films themselves. Taking up American Grafitti, for instance, they describe both what is artistically compelling about the film and how Universal ""quavered and dithered"" about releasing it. Altogether, they are best at analyzing films they like--notably, New York, New York and Sisters--and tend to employ dubious sociological standards when discussing films like Carrie, they don't admire. But they're not afraid to come down hard on celebrated works (Star Wars is ""pinball on a cosmic scale""), and they offer enough insights on Hollywood filmmaking that ""cine-literates"" may be willing to overlook their simplistic thesis.