There's virtually nothing harmful in Diminished Capacity, a mild comedy about the difficulty of selling a rare baseball card when you're a picturesque old geezer with a faulty memory. The most appreciative audience will be, in fact, not the one that is interested in geezers, but the one that is interested in baseball; more specifically, interested in baseball fans and their fanaticisms—particularly the incandescence of those devoted to the "Lovable Losers," the Chicago Cubs.
The story begins with Cooper Zerbs (Matthew Broderick), mild-mannered editor with a Chicago news syndicate, who intervenes in a fight between a girl and a drunk coworker and ends up with a concussion. When we meet him, he's been convalescing for months, but still doesn't notice that the words of love in a strip cartoon should be coming from the mouth of the woman, not the dog. However, he has a new worry; his mother says that eccentric uncle Rollie (Alan Alda) is becoming more unhinged, and she needs Cooper to wrestle him into the kind of eldercare known as "benign confinement."
Cooper arrives at the ramshackle family home in rural Missouri to find that Rollie is continuing his long-term hobby of collecting poetry from fish. He has set up an old typewriter on the pier, with an unbaited hook tied to every key; on occasion the keys are tugged, and Rollie attempts to extricate words from gibberish. (This quirk inspires a lovely opening title sequence.) He's convinced that the fish are poetic prodigies; they are "deep." But now he's developing new hobbies, such as drying socks by turning on a propane burner and letting it hiss for long minutes as he tries to strike a match. Cooper's mom has reason for concern.
Rollie is determined to finish his life ...1