The function of a catcher in baseball is to act as the player positioned behind home plate, responsible for receiving pitches and making defensive plays. Catchers play a vital role in game strategy, signaling pitches to pitchers and managing the game's tempo. They must be adept at blocking pitches in the dirt, fielding bunts, and controlling the running game by throwing out baserunners. The catcher is also essential for communicating defensive alignments and supporting the pitching staff throughout the game.