From chatgpt.

There are many American football coaches who have achieved a great deal of success and are considered among the best of all time. Some of the most widely recognized coaches in the history of American football include:

Vince Lombardi - Lombardi is widely considered to be one of the greatest coaches in the history of American football. He led the Green Bay Packers to five NFL championships in the 1960s and helped establish a winning culture for the team. Bill Belichick - Belichick has won six Super Bowl titles as the head coach of the New England Patriots and is widely regarded as one of the most successful coaches in NFL history.

Paul Brown - Brown was a pioneering coach who helped establish the modern era of professional football. He is credited with developing many of the tactics and strategies that are still used in the game today.

Tom Landry - Landry coached the Dallas Cowboys for 29 seasons and led the team to two Super Bowl titles. He is widely regarded as one of the most innovative coaches in NFL history. Don Shula - Shula is the winningest coach in NFL history, with 347 victories over his career. He won two Super Bowl titles with the Miami Dolphins and is widely respected for his longevity and consistency.

Ultimately, the best American football coach of all time is a matter of opinion, and different people may have different criteria for what makes a coach great. However, these five coaches are widely recognized as some of the most successful and influential coaches in the history of the sport.