by Bradley Streeter

Created on: December 04, 2008   Last Updated: January 13, 2009

The key to understanding football defense is to know the basics of each position and the various packages and formations used by both offense and defense. Playing football defense requires a great deal of teamwork and trust that your teammates will meet their assignments.

The term "package" refers to the specific group of players put on the field for a play. The term "formation" refers to the manner in which the players are lined up prior to the play. Packages and formations are determined by the circumstances of the game. For example, if the offense has a long way to go, they may use more fast players and fewer blockers. The defense has to find the proper package and formation to match the offense.

There are three general classes of defensive positions. Defensive linemen are usually the biggest and strongest, linebackers typically have a good balance of size and speed and defensive backs are the lightest and fastest defenders.

Defensive linemen are generally responsible for occupying blockers and penetrating the line of scrimmage. If passing, this makes the quarterback hurry and hopefully leads to mistakes. If running, this gives the runner fewer lanes to choose from and allows linebackers to find the runner, unimpeded by blockers.

The responsibility of linebackers depends on the play that the defense expects to be run. If the offensive formation hints at a pass, a linebacker may cover an offensive player or a zone of the field to prevent a pass in that direction, or the linebacker may blitz, attempting to hurry the quarterback even more.

If the offensive formation hints at a run, the linebackers have an assignment depending on their place in the formation. They may fill a hole created by the blockers or they may "seal the edge" so that the runner cannot get past the end of the line.

Defensive backs are further divided into cornerbacks and safeties. The cornerbacks almost exclusively cover an opposing receiver or a zone. Safeties may also cover, but their main job is to be the last line of defense. During a pass, the safety cannot let an opposing player pass him. During a run, the safety must move up and stop the runner before he can get far.

Typical defensive formations include the 4-3 (four linemen and three linebackers), the 3-4 (three linemen and four linebackers) and the nickel defense (three linemen, three linebackers and five defensive backs). You may also hear generic descriptions for formations such as "cover 2", where two safeties each protect a zone, or a "loaded box", where the majority of the defense is near the line of scrimmage and defensive backs are most vulnerable.

There are many plays that a football defense can run from each formation. The defense may blitz with a linebacker or defensive back, hoping to disrupt the quarterback but leaving them vulnerable. They may play a zone defense, hoping to confuse the quarterback into a bad pass. Or they may play man-to-man, giving the quarterback more opportunity, but stifling certain plays. More often than not, a defensive play will have some of each, mixing zone and man-to-man coverage, or giving defensive players the opportunity to "read" the offense and decide whether to blitz or wait for the ball.

Playing football defense is very complicated, depending on predicting the offense and reacting to what happens. Hopefully a basic grasp of the positions, packages and formations employed by a football team will allow you a better understanding of what the defense is doing.

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