As Sadie Hawkins Day approaches, Daisy Mae hopes to win the hand of Li'l Abner by catching him in the traditional race. A senator comes to visit to tell the residents of Dogpatch that their town ...

The graph tends to show shifting, rounded curves that resemble the lumpy, bubble-shaped shmoo character in the Li'l Abner comic strip series. The term is also a verb: "to shmoo" is to run the test.