California Split

Old school poker. "California Split is a 1974 film directed by Robert Altman and starring Elliott Gould and George Segal as a pair of gamblers.
The film is less concerned with plot than behavior as we watch the friendship between Bill (Segal) and Charlie (Gould) develop over a mutual love of gambling. Charlie is a wisecracking joker and experienced gambler constantly looking for the next score. Initially, Bill isn’t as committed a gambler (he works at a magazine during the day) but he’s on his way. As the film progresses and the two men hang out more, Bill starts to become more addicted to the gambling lifestyle." source: Wikipedia.
Keep an eye out for a very young Jeff Goldblum, and Amarillo Slim playing himself.