A tactic used by defensive players while tackling an opposing ball carrier. The goal is to force the player to fumble the ball, giving the defensive the opportunity for a turnover. This is done by reaching for the ball and pulling at it, hoping that the ball carrier loses his grip and the ball bounces away. The problem with attempting to strip the ball can be that it limits a player's ability to wrap up the ball carrier and bring him to the ground, thus allowing the player to gain more yards or break the tackle.
Since turnovers can change the flow of a game dramatically, managing to strip the ball can be of huge benefit to a defense. Defensive players will often seek to yank the ball away from the ball carrier on most tackles. Sometimes, a defensive player who has wrapped up a player will hold him up for a second, allowing the rest of the defense to swarm to the player and strip the ball. Offensive players will combat the possibility of a strip by holding the ball with two hands and securing it, reducing the opportunity of a fumble. Another way to strip the ball is to run up behind a ball carrier and swing down on his ball hand, knocking the ball to the ground.