Few movie stars are more ubiquitously typecast than Benedict Cumberbatch, whose rise to cultural prominence has been nothing short of meteoric. Cumberbatch is now a go-to star for directors seeking a genius or supervillain, coupling a certain aristocratic British charm with a Sheldon Cooperesque tendency to hold average society in utter contempt. “The Imitation Game,” in which Cumberbatch stars as cryptologist and early computer engineer Alan Turing, capitalizes on these strengths while simultaneously probing deeper.