• The onside kick may be a team's last chance to win the game.Football image by Brian Garvey from Fotolia.com
  
  The onside kick exists as a final effort for a losing NFL team to win the game. It works infrequently at best, but in some situations, it may be the only option a team has. Most of the time, an onside kick takes place at the end of the game, but in some circumstances, it can take place earlier as a way for teams to take their opponents by surprise.
  
  

Basics

• Normally after scoring, an NFL team kicks the ball back to the opposing team. If the team that has just scored is still losing in the last few minutes of the game, they cannot afford to give the ball back. Otherwise their opponent can run the clock out by running plays slowly and thus win the game by default. The onside kick takes advantage of official NFL rules to deny the other team possession of the ball, and thus score additional points very quickly.
  
  

Distance

• Every kickoff in the NFL needs to travel at least 10 yards to be legal, and the kicking team cannot touch it before it travels 10 yards, except in cases where the opposing team has touched the ball. An onside kick therefore needs to either be as close as possible to 10 yards while still traveling over that length (in order to give the kicking team a chance to close the distance and grab the ball). Or, the kicking team needs to get it to come into contact with a member of the receiving team without that player taking firm possession of the ball (such as when the ball bounces off his arm or chest). If the ball bounces off the opposing player, it becomes live and the kicking team may be able to snatch it up.
  
  

Possession

• The kicking team may recover the onside kick after it travels 10 yards, but cannot advance it unless the opposing team demonstrated possession of the ball and lost it. Accordingly, both teams tend to send their "good hands" players onto the field: players who are adept at plucking the ball out of the air and holding onto it, as well as being fast enough to close the distance between themselves and the ball quickly.
  
  

Penalties

• If the kicking team touches the ball before it travels 10 yards or kicks the ball out of bounds, they suffer a five-yard penalty and must kick the ball again. If they kick the ball out of bounds or fail to let the ball travel 10 yards a second consecutive time, the receiving team automatically takes possession of the ball at the "dead ball" spot where the officials ruled.