A longtime columnist for The Washington Post, he also wrote dozens of books about basketball, baseball, tennis, golf, football and the Olympics, many of them best sellers.

John Feinstein, an indefatigable sportswriter for The Washington Post and the author of more than 40 books, including the best sellers “A Season on the Brink” (1986) and “A Good Walk Spoiled” (1995), died on Thursday at his brother’s home in McLean, Va. He was 69.

His brother, Robert, said the cause was probably a heart attack.

Mr. Feinstein’s last column, about Michigan State men’s basketball coach, Tom Izzo appeared in The Post on Thursday.

Mr. Feinstein became one of America’s best-known sportswriters after “A Season on the Brink,” which focused on the 1985-86 Indiana University basketball team led by the mercurial coach Bobby Knight, became a best seller. The book gave readers the kind of journalistic access to Mr. Knight — a brilliant tactician but a complicated personality — that sports books usually did not offer.

Although Mr. Knight didn’t speak to Mr. Feinstein for eight years after the book’s publication — angry about all the profanity that spilled from his mouth and onto its pages — Mr. Feinstein praised the coach after his death in 2023  for boosting his career.

In a column for The Post, Mr. Feinstein wrote that the open door Mr. Knight gave him made “A Season on the Brink” an enormous success, “which has allowed me to pick and choose book topics for the past 38 years.”

“Not once did Knight back away from the access,” he added, “even during so

me difficult moments for his team.”

The book was adapted into a television movie in 2002, starring Brian Dennehy as Mr. Knight.

With astonishing speed, Mr. Feinstein wrote and reported books on basketball, baseball, tennis, football, golf and the Olympics. (“A Good Walk Spoiled” is about golfers on the PGA Tour.) He was especially well known for his insightful portraits of athletes and coaches.

His most recent books include two published last year: “Five Banners: Inside the Duke Dynasty” (he graduated from Duke University in 1977) and “The Ancient Eight: College Football’s Ivy League and the Game They Play Today.”

Mr. Feinstein also wrote novels for young readers; his “Last Shot: A Final Four Mystery,” won an Edgar Award from the Mystery Writers of America for best young-adult book in 2006.

His family knew about his work ethic from a young age.

“He was a cuckoo head — seriously,” Robert Feinstein said in a phone interview. “He would watch Met games and keep a box score of every game he watched — and he did that forever.”

A full obituary will appear shortly.