Polo is the only game where it is impossible to use your left hand. The United States Polo Association rulebook states, “All players shall play the mallet with their right hand.”
The reason is the panic created in a situation where a right-handed polo player feels when he and a left handed player approach the ball from opposite directions. A left-handed polo players association was created to fight for their rights and change this rule. Only 3 players in the world have been left handed.