John Feinstein, a sports writer for the Washington Post and the author of 23 New York Times best-sellers, has died. He was 69. His brother, Robert Feinstein, confirmed the death to the Post but said the cause was not immediately clear.

John Feinstein wrote “A Season on the Brink,” an inside look at volatile Indiana men’s basketball coach Bob Knight.

A Washington Post sportswriter, John Feinstein became the best-selling author of more than 40 books, including “A Season on the Brink."