For many sports fans, autumn is a time of death and monotony disrupted only by the weekly punctuation of Sunday NFL games. Never has this been truer than in the 21st century, as “Fantasy Football” has become an obsessive fixation for millions of rabid subscribers. But even their fandom pales in comparison with that demonstrated by late author Frederick Exley in the 1950s and early ’60s.

According to his “fictional memoir,” Exley spent his Sundays in a murky bar watching his beloved New York Giants and their star running back/wide receiver Frank Gifford clash with opponents. He would physically act out every play while offering a frantic running commentary on the game, guzzling beers during the huddles as other patrons looked on in amazement. “Oh, God, he did it! Gifford did it! He caught the goddamn thing!” he would holler after a reception.

For a man who fancied himself of exceptional intelligence and dreamed of literary eminence, football might not seem like the most enlightened of hobbies. In “A Fan’s Notes,” Exley attempts to explain his crazed obsession with the game, derived largely as a diversion from the sad circumstances of his life, which was characterized by chronic alcoholism and repeated admissions into mental institutions.

Although undeniably a gifted writer, Exley was not wired for life in conventional society. A native of Watertown in upstate New York, he attended school first at Hobart College and then at the University of Southern California, where a young Frank Gifford was rapidly becoming an All-American star.

After graduating, Exley enjoyed a brief period of employment before losing his job and entering a prolonged stretch of indolence, inebriation and mental illness. All this is described with tremendous insight and humor in the book, which serves not only as a chronicle of Exley’s life, but as an indictment of the culture in which he lived. In a way, Exley’s failures reflect the intangibility of the American dream.

That’s not to say Exley is some kind of martyr. His behavior and attitude in the book are marked by depravity, and he manages to uphold an unhealthily bloated ego even while spending month after slothful month on the davenport—either that of his mother or of some overly munificent friend. It’s as if, in his addled mind, Exley felt he was too righteous and superior to hold a common man’s job.

And yet, Exley also ridicules himself, recognizing the improbability of finding success as an author and acknowledging his irreconcilable shortcomings as a husband and father. Exley is openly aware of the fact that his infatuation with Frank Gifford stems largely from his vicarious fantasies of fame and adoration. When a woman suggests he ought to be envious of Gifford, he responds with incredulity. “But you don’t understand at all. Not at all! He may be the only fame I’ll ever have!”

As it would turn out, Exley did achieve some measure of celebrity before he died in 1992, but of a limited sort. Although he would produce two more semi-autobiographical novels, they were not nearly as successful as “A Fan’s Notes.”

But maybe one brilliant novel is enough. Exley’s writing in “A Fan’s Notes” is breathtaking, and his observations—whether describing a doomed romance, a door-to-door sales job or a stint in a mental asylum—are brimming with dark humor and shrewd cynicism. His mastery of the language is striking, and most any reader will be able to relate to some facet of his candid self-analysis.

“For my heart,” Exley writes in a letter to his estranged wife, “will always be with the drunk, the poet, the prophet, the criminal, the painter, the lunatic, with all whose aims are insulated from the humdrum business of life.”

Though he may not have a seat beside Hemingway in America’s literary pantheon, Exley has earned several posthumous tributes. Literary critic Jonathan Yardley published his biography, “Misfit: The Strange Life of Frederick Exley,” five years after his death. Last year, author Brock Clarke published a novel called “Exley,” which he presented at RiverRun Bookstore in Portsmouth. Perhaps Exley is better suited to immortality in fiction than he was to life in reality.