Subtly subversive in his fiction — less so in his left-wing political writing — he consistently upended expectations with a cocktail of fiction and fact, remixed in book after book; with clever and substantive manipulations of popular genres like the Western and the detective story; and with his myriad storytelling strategies. Deploying, in different books, the unreliable narrator, the stream-of-consciousness narrator, the omniscient narrator and multiple narrators, Mr. Doctorow was one of contemporary fiction’s most restless experimenters.