"Who's on First?" is a comedy routine made famous by Abbott and Costello. The premise of the sketch is that Abbott is identifying the players on a baseball team for Costello . Federation under the ring name "Who" in , serving as an excuse for commentators to make "Who's on First" jokes during his matches. In One of the most famous baseball comedy acts to ever take place was the following Abbott: I say Who's on first, What's on second, I Don't Know's on third. In , they performed Who's on First, a rapid-fire routine that had been in the National Baseball Hall of Fame and Museum in Cooperstown, New York.
Costello: I love baseball. Abbott: We all love baseball. Costello: When we get to St. Louis, will you tell me the guys' names on the team, so when I go to see them . Abbott: Well, let's see, on the team we have uh Who's on first, What's on Abbott: I say, Who's on first, What's on second, I Don't Know's on third and then you. Just about the greatest comedy routine ever, by comedians Abbot and Costello, with Abott telling Costello the names of the players. In this context, the first.
The thing is, he doesn't understand it's a joke—that the question "Who's on first?" isn't really a question at all (since there's a dude named "Hu/Who" who is. This is named from a vaudeville routine regarding baseball which, while popular at the Occasionally, characters have this as a running joke about their name.