American football American football American football, referred to as football in the United States and Canada and also known as gridiron, is a team sport played by two teams of eleven players on a rectangular field with goalposts at each end. The offense, which is the team controlling the oval-shaped football, attempts to advance down the field by running with or passing the ball, while the defense, which is the team without control of the ball, aims to stop the offense's advance and aims to take control of the ball for themselves. The offense must advance at least ten yards in four
Formation (American football) player football field. Formation (American football) A formation in football refers to the position players line up in before the start of a down. There are both offensive and defensive formations and there are many formations in both categories. Sometimes, formations are referred to as packages. At the highest level of play in the NFL and NCAA, the one constant in all formations is the offensive line, consisting of the left and right tackle, left and right guard, and a center. These five positions are often referred to collectively as the "line", and have the primary role of blocking. By