Billy Elliott is the name of a hard-ass eleven-year-old British kid who enrages his coal-miner dad by switching from boxing lessons to ballet. Go ahead, groan. I did, too — that is, until I saw stage director Stephen Daldry (An Inspector Calls, Via Dolorosa) transform a potential sapfest into a bracing triumph. Daldry scores a sensational film debut. Working from a sharply observant script by Lee Hall, who sets Billy’s need to dance against the harsh background of a 1984 miner’s strike, Daldry benefits from a superb cast, notably Julie Walters as Billy’s teacher and Gary Lewis as his beleaguered dad. Above all, there is newcomer Jamie Bell, 14, as Billy. Watch your back, Haley Joel Osment: Bell explodes onscreen in a performance that cuts to the heart without sham tear-jerking. When Billy confronts his father not with words or fists but with a dance that gives form and grace to his anger, the result is one of the most powerful scenes of the movie year. Look for Billy to blast off.