Diamond arbiters, also known as umpires, are responsible for making decisions during a baseball game. They are the final authority on all matters related to the rules of the game and are responsible for ensuring that the game is played fairly and in accordance with the rules. Umpires are also responsible for calling balls and strikes, determining whether a batted ball is fair or foul, and making other calls such as safe or out. Umpires must be impartial and have a thorough knowledge of the rules of the game.