The Elaine (Julia Louis-Dreyfus) story was inspired by a real-life experience of Larry David's. David asked executive producer Howard West if he knew anyone who could get him tickets for a Yankees-Angels game at Anaheim Stadium. West knew the accountant of Angels owner Gene Autry and was able to get David tickets to seats in Autry's box behind the dugout. David, a New York native, wore a Yankees cap to game. An Angels executive came down to the box and asked David to remove the cap because it might offend Mr. Autry. David could be seen wearing the hat on the front page of the Los Angeles Times sports section the following day.
After being hit in the head by a baseball, Kramer (Michael Richards) refers to Elaine (Julia Louis-Dreyfus) as "Carol" and to George (Jason Alexander) as "Mike." This is a reference to Carol Leifer, on whom Elaine is partly based, and Michael Costanza, a friend of Jerry Seinfeld's whose last name was used for George.
The film Nina (Catherine Keener) plundered for her letter to Jerry (Jerry Seinfeld) is Chapter Two (1979), starring James Caan. Elaine (Julia Louis-Dreyfus) also mentioned Neil Simon who wrote the script for the film.