The quarterback (QB) is a position in gridiron football who are members of the offensive side of the ball and mostly line up directly behind the offensive line. In modern American football, the quarterback is usually considered the leader of the offense, and is often responsible for calling the play in the huddle. The quarterback also touches the ball on almost every offensive play, and is almost always the offensive player that throws forward passes. When the QB is tackled behind the line of scrimmage, it is called a sack. The position is also colloquially known as the "signal caller" and "field general".[1]