: The team without the ball tries to stop the offense's advance by tackling the ball carrier, intercepting passes, or forcing fumbles to gain possession. Player Units and Positions
Teams utilize a "platoon system," switching between three specialized units: american football
: Includes the defensive line , linebackers , and the secondary ( cornerbacks and safeties ), who work to prevent scoring and force turnovers. : The team without the ball tries to
: The team with the ball (offense) has four chances, known as downs , to advance the ball at least 10 yards. If successful, they earn a "first down" and another set of four downs to continue their drive. known as downs