Football Defense

The aim of the defending side is to prevent offense from advancing and scoring. This is done by taking the ball away or preventing the players from advancing beyond the scrimmage line. By stealing the ball away they can go ahead and score points. There are linemen, linebackers and defensive backs in the defense lineup. Positions and to some extent, functions vary according to the offense and the strategy employed. The thrust point is the defenses' nose guard, the strongest player who can push back the center or act as a guard. There is also the defensive tackle lining up against the center and they are the most powerful physically.

Defending teams form defense lines made up of four down lineman and three linebackers in a 4-3 formation or in a three down linemen and four linebackers in 3-4 formation. The other options are five linemen and two linebackers in a 5-2 formation and three linemen, three linebackers and five defensive backs in a 3-3-5 formation. The purpose is to defeat the offensive teams objective of advancing and scoring. The formation modulates in line with the offensive's attacking strategy and flow of game.

Defense players wait until the center snaps ball into play and then move into action.

A run defense concentrates on preventing offense from gaining yardage, placing more players close to the scrimmage in order to get to the ball carrier. If offense tries to play a passing game, then a pass defense comes into action. Sometimes, defense goes into a blitz, rushing the quarterback in various ways.