The Truth Behind Abbott And Costello's Popular 'Who's On First?' Routine

"Who's on First?" (which can be seen here via YouTube) relies on the Straight Man, in this case Abbott, feeding information to the Stooge, in this case Costello, who fails to understand what he's being told because the words he's hearing can have two meanings. The audience laughs hysterically while an increasingly frustrated Costello hears "Who is on first?" and thinks he's being asked the same question he just asked, while Abbott is telling him that the first baseman is actually named "Who."

Such bits that rely on misunderstanding based on multiple word meanings had been around well before Abbott and Costello got big. The structural basis for "Who's on First," according to the Library of Congress, may have been a minstrel routine called "Who's the Boss?" in which the boss was named "Who" and the employees were "What" and "Ida Know." Other performers then began adapting the bit to baseball, which was not uncommon in the show business of the era. Abbott and Costello took the basis for those sketches and made it their own, using baseball references instead. The duo first performed "Who's on First?" in 1937, and over the course of their careers, would go on to repeat it hundreds if not thousands of times.