Much maligned in the past for his footballing philosophy and underhand tactics, the Sunderland manager is in reality a deep thinker about the game who has learned his trade the hard way Sam Allardyce is the sort of man who walks into a packed room and immediately dominates it. If that hardly ranks as a rare trait among football managers, particularly those standing 6ft 3in, the difference with Allardyce is that he really listens to …