Martin Balsam won his Oscar from his only nomination for portraying Arnold Burns in A Thousand Clowns.
A Thousand Clowns is a terrible film because it is one of those films that thinks it has a profound message but comes off as just pretentious, as well as because it is one of those comedies that after it tells its "jokes" you don't laugh at them, but oh boy do those characters laugh at them. Martin Balsam plays the brother of the obnoxious Murray, who also acts as his agent as well.
Martin Balsam is a character actor that I sort of like, not one of my favorite but he usually adds to a film rather than take away from a film. Here though Balsam cannot really overcome the material which is at hand. Although Arnold is considerably less annoying that Murray or Nick that does not stop him from begin pretty annoying himself. Although he is not all the time, Arnold has his annoying moments where Balsam overacts a great deal.
These overacting moments come really from the material where he finds Murray's antics funny or is required to bring attention to a joke that he has made as well. Balsam over does his facial reactions in all of these moments that come off as just obnoxious opposed to anything entertaining endearing. Balsam's performance is not entirely overacting though.
Balsam does have a few minorly better moments when he questions Murray's philosophy. There is certain degree of sensibility as well as satisfaction suggested fairly subtly within himself that refreshing in the face of Jason Robards' theatricality as Murray. Balsam though is only refreshing at best though, his performance still amounts to very little in the end, and in many moments fails to overcome the awfulness of the film.