Great performances in lighthearted roles are hideously undervalued; one need only consider the total number of competitive Oscars awarded to Cary Grant (hint: the number starts with a 'z') to recognize that grave, dramatic characterizations are more impressive to most people than are relaxed, funny ones. Everybody seems to think that movie stars can be appealing and sexy and likable on demand, without expending any effort whatsoever -- it's the ability to convincingly suffer onscreen that separates the stars from the stand-ins. So few people will likely concur when I suggest that Kevin Costner's wry, low-key, intensely charismatic work in Tin Cup constitutes one of the year's best performances. Some of you are probably gasping aloud right now, in fact. Get wise: Costner, who's invariably stiff and monotonous in Superguy roles (my head still hurts from enduring his endless summation in JFK five years ago), is Hollywood's best contemporary romantic comic, and his portrayal of Roy "Tin Cup" (dumb nickname, dumb title) McAvoy, an unambitious golfer more interested in sinking impossible shots than in winning tournaments, is first-rate. I wish the film itself were as brilliant as he is; instead, it's a fun, pleasant, above-average movie which suffers mostly from the fact that it isn't Bull Durham. That film, also written and directed by Shelton and starring Costner, was one of the best films of the last decade (no, really, it was -- watch it again), and Tin Cup bears more than a passing resemblance to it...except that golf isn't baseball (no mythic quality, no camaraderie, no ridiculous hand signals), Rene Russo isn't Susan Sarandon (though her work here, unlike that in In the Line of Fire and Get Shorty, is at least tolerable), and Don Johnson definitely isn't Tim Robbins (no parenthetical comment required, I trust). Tin Cup is too often crass and obvious when it should be subtle and sly, particularly where Johnson's smarmy antagonist is concerned. Most of the time, though, it's refreshingly intelligent and assured. Shelton's dialogue (the script was co-written with John Norville, but most of the dialogue is unmistakably Shelton's) is typically hilarious and goofily verbose, and the story moves briskly and resolves in an unpredictable and immensely satisfying way. (I speak here of the resolution of the U.S. Open -- the film's final scene is kinda lame, actually.) And then there's Costner, who, if he's smart, will volunteer for all of Shelton's future projects. Excepting Cobb 2, of course.