How should a coach signal for a pitching change?

A coach should signal for a pitching change through verbal communication to the umpire because this method ensures that the communication is clear and official. When a coach approaches the umpire and informs them of the change, it creates a formal record of the action, which is important for maintaining the game's integrity and ensuring that all parties—players, umpires, and spectators—are aware of the change.

While there are various gestures and signals used in baseball for different situations, verbal communication is the most direct and least prone to misinterpretation. Other methods like holding arms outstretched or specific hand gestures might not have universal recognition or could cause confusion. Calling time on the field is also a necessary procedure but is not sufficient on its own to indicate a pitching change without the accompanying verbal notification to the umpire. Hence, the emphasis on verbal communication highlights the importance of clarity in the game.