A quarterback (QB) is a position in American and Canadian football. Quarterbacks are members of the offense, or attacking team. They line up directly behind the center, in the middle of the offensive team's line. A quarterback is usually the leader, and starts most plays. In addition, the quarterback gives commands to the other players before the start of a play. A quarterback will in most attacking plays throw the ball to a member of their team, ready to run to the end of the pitch. Quarterbacks may also run the ball themselves, as well as hand the ball to a runningback. These players are usually the faces of their respective teams. Some very notable players at this position in history are Tom Brady, Jim Kelly, and Peyton Manning.