Plot

Jerry learns that his new artist friend, from whom George has been forced to buy a painting, plagiarized a letter to keep him from breaking up with her. Elaine refuses to remove her Baltimore Orioles cap during a New York Yankees game.

Jerry's new girlfriend, Nina, is an artist and while he likes her a lot he's a little concerned that she is overly possessive and jealous. It clearly bothers her that he and Elaine have remained such good friends even after they stopped dating. When Jerry obviously begins to waver, she writes him a wildly romantic letter. Only later does he realize it's a piece of dialog given by Marsha Mason in Chapter Two (1979). Sitting in the owner's box at a Yankees game, Elaine insists on wearing her Orioles cap and refuses to remove it when asked to.—garykmcd

Kramer poses for a portrait to be painted by Jerry's new girlfriend, Nina (Catherine Keener), which an elderly, art-loving couple (Elliott Reid and Justine Johnston) admire. Kramer tells Nina that Elaine and Jerry were a big thing back in the day. She feels that Jerry and Elaine being friends now is strange. George feels obligated to buy something when he accompanies Jerry to Nina's art studio, especially when she offers George her father's tickets to the owner's box at Yankee Stadium. Jerry cannot come as he has a show out of town that weekend. Jerry tells George that Nina is the jealous type and doesn't like when he has fun with anyone except her. George then reluctantly purchases a painting from Nina, not knowing how much it cost.

With Nina's tickets, George brings both Elaine and Kramer to the owner's box at Yankee Stadium. In order to get out of a prior engagement (her boss's son's Bris), Elaine lies to her boss, Mr. Lippman, saying she must tend to her ill father. However, once the three are seated in the box, they are met by Nina's father who is a Yankee's accountant. As they are seated in the New York Yankees owner's box, Nina's father insists that Elaine remove her Baltimore cap. Elaine refuses to remove her Baltimore Orioles baseball cap and they are consequently evicted. In the melee Elaine throws George's cap over the player's dugout. Kramer, while attempting to climb over the dugout to pick up George's cap, is struck in the head by a baseball. At the same time, Nina and Jerry have an argument and break up. Nina says that Elaine was a guest of her father and should have taken off the baseball cap. Jerry defends Elaine and says that it was preposterous to make such a request in the first place. Nina tells Jerry to ask George to pay her $500 for the painting. This makes George livid and he refuses to pay for it.

Upon returning to Jerry's apartment, Elaine discovers her confrontation in the Yankees' owners' box was published with a picture in the sports section of the paper. After an unsuccessful attempt at stealing the sports section of the paper from his office, Elaine fears her boss will realize and fire her. Meanwhile, a poetic and emotional letter is delivered to Jerry's from Nina. Although he is initially moved and humbled, Jerry soon finds out, while watching a movie, that the letter was plagiarized from the Neil Simon play Chapter Two. when Jerry is confronting Nina, the elderly couple who admired Kramer's portrait walk in to confirm their purchase for $5000. George sells his painting to Jerry for $10.

Elaine is summoned to her boss's office, whose personal accountant is revealed to be Nina's father. As he recites the baseball cap story over the phone, Lippman is amused and apparently does not realize that the offender was Elaine. He informs her that Nina's father has given him tickets to Yankee Stadium and invites her to wear a Baltimore cap (which she coincidentally has in her office) as a joke.

In the closing scene, Kramer dines with the elderly couple who purchased his portrait, and Jerry and George watch the televised Yankees game, only to find Elaine in yet another cap altercation as described by Phil Rizzuto.