Eugene Onegin, the original antihero of literature, always dressed in black. On stage, in John Cranko's 1965 ballet of Aleksandr Pushkin's 1820s verse novel, the somber color brings Onegin into instant focus in such surroundings as a bright garden, a lively party, a glittering military ball, even in the curtained boudoir. He is the fulcrum of the work that the Stuttgart Ballet danced again in the Kennedy Center at both of its Saturday performances.

Yet Onegin is an enigma. To the other characters, to the audience and especially to himself, he's a cipher, and the performer taking the part has the difficult task of making him plausible without solving the riddle that must remain at his core.

The ballet (and Tchaikovsky's 1878 opera) elevated Tatiana, one of the characters whose lives Onegin affects, to the vacant heroic role. Cranko, especially, makes her as open as the books in which she loves to bury her nose. From plentiful material, the performer taking this part must choose what to show and what merely to suggest.

In other words, "Eugene Onegin" is the sort of ballet that needs the right cast; adequate performances won't do.

Saturday night, Richard Cragun mixed one spoonful of Iago's jealous irony, two of Hamlet's hesitant deliberation and lots of animal lust to make Onegin a narcissist as attractive to others as to himself. Cragun is a sensual dancer; taking an arabesque or launching into a spin, he conveys muscular pleasure as well as the satisfaction of fulfilling a choreographic design. In the afternoon, Tamas Detrich made meticulousness Onegin's principal trait, though it seemed more a matter of the dancer's own temperament than to Onegin's being a snob. Detrich has the looks but not the dash of a matinee idol. His dancing, too, lacks sweep because of its step-by-step neatness. These characteristics, though, are valid for the role.

Marcia Hayde'e, Cragun's Tatiana, introduces herself with simplicity. As the bookish girl who adores Onegin, she remains aloof from the action as much as possible, but, almost like a member of the audience on stage, she observes. But when she does become involved in events, Hayde'e seems to react with spontaneity. It's an exhilarating interpretation.

At the moment when she must disdain Onegin and she becomes a woman, Hayde'e appears to grow in stature; her almost imperceptible stretching doesn't cease until the curtain comes down on the scene.

Annie Mayet, Tatiana in the afternoon, is well on her way to being a dance actress of stature. She has modeled herself on Hayde'e and while not everything is yet projected at quite the right dynamic level, she's a stronger technician than her mentor is now. This made a crucial difference in the final scene. Hayde'e wasn't fully up to to Tatiana's ultimate encounter with Onegin, in which she's momentarily seduced but then issues a rejection that is irrevocable. Cragun had to pull Hayde'e through some of the strenuous adagio.

Perhaps to compensate, perhaps giving in to her instinct for improvisation, Hayde'e overacted. Her histrionics elicited an ovation, but Mayet, with her finely controlled counterpoint of feelings and increments of pathos, produced a more haunting impact.