California Split (1974) on Netflix

When a casual gambler (George Segal as Bill) befriends a professional one (Elliott Gould as Charlie), he begins to mirror his life, sending both deeper into the sleazy gambling world where the stakes keep getting bigger.

A down on his luck gambler (George Segal as Bill) links up with free spirit Elliot Gould (Elliott Gould as Charlie) at first to have some fun, but then gets into debt when Gould takes an unscheduled trip to Tijuana. As a final act of desperation, he pawns most of his possessions and goes to Reno for the poker game of a lifetime. A film set mainly in casinos and races, as the two win and lose (but mainly win), get robbed, and get blind drunk.

—David B-2

Bill Denny (George Segal) and Charlie Waters (Elliot Gould) meet when they are both on the same end of a fellow gambler's wrath at a Southern California gambling club. Bill is a casual gambler who has a full-time job as a magazine writer; whereas Charlie is a small-time career gambler, with the moxie to match his need to portray himself as the winner, specifically to those at his poker table. As Bill and Charlie spend more time together, Bill begins to want to emulate Charlie's life, including hanging out with Charlie's prostitute friends, Barbara Miller (Ann Prentiss), but most specifically Susan Peters (Gwen Welles). Bill even goes into debt to his loan shark as he gambles more. Regardless, Bill and Charlie try to raise enough cash to take a trip to Reno with the goal for Bill to win some money at among others a high-stakes poker game, but more importantly to get the gambler's fix associated with winning big.

—Huggo