Still the greatest? Never was.
The undisputed greatest all time coach is Guy Chamberlin. Chamberlin won four NFL championships as a player-coach. He won 78.4% of the games he coached in the NFL, the highest winning percentage all-time for a coach with 50 or more games.
I'd like to see Bill Belichick strap on the pads and take a few snaps. Until then, he's just a poorly dressed guy with a headset getting all his ideas from some guys in the booth.
Coaches, Records, and Coaching Totals
www.pro-football-reference.com