Non-verbal communication is not just commonplace in team sports, it is sometimes essential to the success or failure of a team. The game of baseball is ruled by the giving, and sometimes stealing, of signs and signals, and other team sports have their own unspoken codes that allow teams to work together without giving away their secrets to the opposition.
The most common non-verbal communication in all of sports is the signs passed between a pitcher and catcher in baseball. Before every pitch is thrown, the catcher will put down a sequence of finger signs, with the number and order of hand signals representing a certain type of pitch. For instance, one finger almost always means "throw a fastball." In turn, the pitcher accepts the sign with a nod or "shakes off" the catcher with a shake of the head, indicating he wishes to throw a different pitch.
Unlike other sports, where timeouts and headset communications allow coaches and players to discuss strategy during games in relative privacy, baseball managers must make their intentions known to batters, runners and fielders through an intricate series of hand gestures, often relayed through the first and third-base coaches. Signs for stealing, hit-and-run, taking pitches and defensive positioning are related with a series of coded hand movements, such as wiping a hand across the chest or touching the hat with a particular hand. Often several signs are given at once to discourage the opponent from trying to decode the sequence.
In football, a quarterback often must resort to using non-verbal communication at the line of scrimmage, especially in noisy, opposition stadiums. A common non-verbal signal is directed to the wide receivers. To indicate which receiver should go in motion from one side to the other, the quarterback will tap the hip of his center on the side of the leg in which the receiver is lined up, cuing the receiver to make his move. In the shotgun formation, the quarterback will use a "silent snap" by tapping his foot on the ground, indicating to the center to hike the ball.
Basketball point guards use verbal and non-verbal cues to call out plays in a half-court set. Sometimes, he will call out a word, which is the code for a particular play. But he will also use a non-verbal code, such as a clenched fist over his head, or by holding up a certain number of fingers, to indicate the number of a pre-determined play.