The cause was complications of pneumonia, his son, Martin, said.

A writer whose shrewdness and insight trumped his style, which was plainspoken and realistic, Mr. Asinof was productive and versatile. He wrote more than a dozen books, including a novel, “Final Judgment,” that is set on a college campus and concerns a protest to keep President Bush from delivering a commencement address, and is to be published in September by Bunim & Bannigan.

Weeks before his death, his son said, Mr. Asinof completed a memoir of his World War II service in the Army Corps on Adak Island in the Aleutians. “Seven Days to Sunday,” his 1968 account of a week in the life of theNew York Giants football team as it prepared for a game, was an early if not groundbreaking enterprise of journalistic embedding in the world of sports.

His first novel, “Man on Spikes,” published in 1955 and based on a longtime friend who spent years in the minor leagues, was a prescient condemnation of baseball’s feudal control over the players. That system was not dissolved until 1975 with the abolition of the so-called reserve clause in standard contracts, which allowed teams to retain in virtual perpetuity the services of players in their employ.

Mr. Asinof also wrote for television and the movies, although his published credits were limited, probably because he was among the many writers who were blacklisted in the 1950s. In his case, he once wrote after he got hold of his F.B.I. file, the blacklisting came about because “I had at one time signed a petition outside of Yankee Stadium to encourage theNew York Yankees to hire black ballplayers.”

But he is best known for “Eight Men Out,” published in 1963, and for the 1988 movie of the same title.

The book is an exhaustively reported and slightly fictionalized account of how eight members of the 1919 Chicago White Sox allowed their anger at the parsimonious team owner, Charles Comiskey, to corrupt their integrity, leading them to welcome the overtures of gamblers, who persuaded them to throw the World Series against theCincinnati Reds. A seminal event in the history of the game, it led to the appointment of the first baseball commissioner, Kenesaw Mountain Landis.

Mr. Asinof spent nearly three years researching the book, including interviewing Happy Felsch, one of several members of the team who were still alive. In the end, “Eight Men Out” was a book that made plain the connection between sport and money and between sport and the underworld. “Here is the underbelly of baseball vividly dissected,” said Fay Vincent, the former baseball commissioner.

In the Camelot of the Kennedy 1960s, the book also made plain, if only by inference, the unsavory potential in American culture, a theme that ran throughout Mr. Asinof’s work. Twenty-five years later, “Eight Men Out” was made into a popular film directed by John Sayles, with a script by Mr. Sayles and Mr. Asinof.

Eliot Tager Asinof was born in Manhattan on July 13, 1919, and he grew up in Manhattan and Cedarhurst, N.Y. His grandfather Morris, a Russian immigrant, was a tailor who eventually opened a men’s store in Manhattan.

Eliot’s father, Max, worked there, and when young Eliot went to work there as well, it was a tenet that he had to sew a suit before he would be allowed to sell one.

The dexterity he developed served him well. Mr. Asinof was an accomplished amateur pianist and sculptor. He was also a carpenter who in 1985, with his son, built the Ancramdale house he lived in for the rest of his life. He shot his age on a golf course for the first time at 79.

“He was really proud of that suit,” said his son, who lives in Tillamook, Ore. Mr. Asinof is also survived by a sister, Betty, who lives in the San Francisco Bay Area.

After graduating from Swarthmore, Mr. Asinof played baseball briefly in the minor leagues — he was a first baseman in the Philadelphia Phillies’ organization — before he joined the Army. When he returned, his son said, the Phillies invited him to return, but he pulled a muscle during his first practice, and that was it for his sports career. He turned to writing.

He also had a gift for finding the company of other gifted people. A compact man with a gravelly voice and a New York accent, he was gregarious and shrewdly charming.

A friend, at various times in his life, of the violinist Yehudi Menuhin and Joe DiMaggio, Mr. Asinof was married once, to Jocelyn Brando, Marlon’s sister. Their marriage lasted five years, ending in divorce in 1955. They met, his son said, in 1949, while Marlon Brando was starring on Broadway in “A Streetcar Named Desire” and Jocelyn was starring in “Mister Roberts.”

“As I always heard the story,” Martin Asinof said, “my father was on a date with Rita Moreno, and the four of them met for dinner. And Brando took a shine to Rita Moreno, and they left together. And my father was there with my mother.”

Eliot T Asinof