Zimmerman, known as Dr. Z, was one of the first reporters to write about the intricate details of a game others had overlooked. He might explain in great detail how the offensive line was able to spring a running back for big gains in a given game.
His interviews with players and coaches revealed some of the minute details involved in winning football.
He made his mark in the 1980s, long before there were regular programs about the NFL and easy online access to videotape of players and teams.
Born in 1932, Zimmerman was the son of Charles Zimmerman, a union leader and onetime chairman of the Socialist Party of America. Paul Zimmerman embraced his father's pro-labor stances.
He attended Stanford and Columbia and played football at both.
Zimmerman became known nationally while writing for Sports Illustrated, making preseason Super Bowl predictions, picking games each week and choosing All-Pro teams at the end of the season.
He was one of the first NFL draft experts when ESPN began televising the draft.
However, his desire for deep analysis did not work well on television, and many of his TV colleagues did not appreciate his argumentative personality.
Zimmerman's writing career ended in 2008, when he suffered a stroke.