Why is Anton Chekhov (1860-1904) routinely and correctly described as the greatest short story writer ever? All answers to this question will seem inadequate but, to put it very simply, the fact is that Chekhov, in his mature stories of the 1890s, revolutionised the short story by transforming narrative. Chekhov saw and understood that life is godless, random and absurd, that all history is the history of unintended consequences. He knew, for instance, that being good will not spare you from awful suffering and injustice, that the slothful can flourish effortlessly and that mediocrity is the one great daemonic force. By abandoning the manipulated beginning-middle-and-end plot, by refusing to judge his characters, by not striving for a climax or seeking neat narrative resolution, Chekhov made his stories appear agonisingly, almost unbearably lifelike.
Source: A short history of the short story | Prospect Magazine