The Clarke-Asimov Treaty

According to Arthur C. Clarke, one day in the late 1960s he and Isaac Asimov shared a New York taxicab. During the ride they agreed that Clark was the world's leading science fiction writer and second-ranking nonfiction science writer, while Asimov was the leading science writer and second-ranking science fiction writer.

Robert Heinlein, the third member of the "trinity" of science fiction writers who dominate the postwar growth of the genre, was not in the cab, so Clarke and Asimov did not have to deal him in.