The term 'Authority Diamond' is a baseball term that refers to the four people who are responsible for making decisions on the field during a game. These four people are the UMPIRE (3 letters), UMPIRE in Chief (6 letters), League Investigator (3 letters), and League President (4 letters). The UMPIRE is the person who makes the calls on the field, while the UMPIRE in Chief is the person who oversees the UMPIRE's decisions. The League Investigator is responsible for investigating any disputes or complaints that arise during the game, and the League President is the ultimate authority on any decisions made during the game.