Why California Split remains among the most obscure of Robert Altman's extraordinary 1970s oeuvre is a mystery. Its stars -- Elliot Gould and George Segal -- were at the top of their form, free and comfortable working in Altman's off-the-cuff, low-key style. Its supporting cast -- Ann Prentiss, Gwen Welles and especially Bert Remsen, as the cross-dressing old jane "Helen Brown," -- is memorable. And its full gallery of extras (many drawn from the therapeutic community Synanon) populate a surreal gambling netherworld in California and Nevada. Altman is working in highest gear with the layered, semi-improvised and alluringly murky style he pioneered. As in Altman's best work, the story just sort of happens, without much distinction between foreground and backdrop, principal characters and walk-ons. Lacking the rigid and didactic "dramaturgy" of its competitors, California Split endures as one of the most probing examinations of the soul and psyche of the abnormal gambler ever filmed.