How to Install the 4.2.5 Defense

4.2.5 Defensive strategy as any defensive scheme is to prevent the opposing offense from gaining yards and scoring points, either by preventing the offense from advancing the ball beyond the line of scrimmage or by the defense taking the ball away from the offense (referred to as a turnover) and scoring points themselves.



With the 4..2.5 defense, there are four types of players: defensive linemen, inside linebackers, outside linebackers and defensive backs (also called secondary players). These players' specific positions on the field and duties during the game vary depending on the type of defense and adjustments being used as well as the kind of offense the defense is facing.



The defensive linemen line up in front of the offensive line responsibility is to prevent the offensive line from opening up running lanes for the running back or to sack the quarterback, depending on whether the play is a passing or running play. Most of the time, defensive linemen attack the offensive line but in some plays they drop back in pass coverage to confuse the opposite team and this is called a zone blitz.



Defensive tackle: The defensive tackle ("DT") lines up against the guard or center on the offensive line. Defensive tackles are generally the biggest and most powerful players on defense; many of them are of the same size as the offensive line or depending upon the defensive philosophy small, aggressive and fast. They tend to be more the "run-stopping" type rather than being good at rushing the quarterback themselves.



The 4.2.5 features two defensive ends who in most cases will line up just outside of the offensive tackle or tight end if the offense uses one. Defensive ends need to be strong enough to be able to not be pushed back by the offensive line, yet fast enough to run around the offensive tackle. There are different types of defensive ends; some are about as strong as DTs and are considered more adept at stopping the run, while others are fast and agile, and are much better at rushing the quarterback than stopping the run.



The 4.2.5 features two inside linebackers (Mike & Will) who align behind the defensive linemen or set themselves up on the line of scrimmage. Depending on the type of defensive strategy being used, a linebacker's responsibilities can include helping to stop the run, rushing the quarterback, or dropping back in pass protection. Mike linebacker is known as the plugger or the bigger linebaker of the two. The Will linebacker is the smaller and usually the fastest because of his ability to drop into coverage.



Outside linebackers: The outside linebackers (Sam, Rover) set up on the outside portion of the line of scrimmage. They are often used to rush the quarterback. OLBs tend to be the fastest and most agile linebackers on the defense and must be able to be active in pass drops when defending the pass.



Defensive backs align behind the linebackers. Their primary responsibility is pass coverage, although they can also be involved in stopping the run or rushing the quarterback.



Cornerback: The cornerback ("CB") lines up opposite the opposing offense's wide receiver(s). Their main job is to cover wide receivers and prevent them from catching passes, or tackle them if they do.



Safety: A defense's safeties ("S") are usually the farthest away from the line of scrimmage when the play starts. Their job is to help the cornerbacks cover receivers and, if necessary, help the defensive line and linebackers protect against the run. Because of this "do everything" role, most safeties are the best all-around athletes on the defense. Safeties are designated as strong safeties ("SS") or free safeties ("FS"). The strong safety typically plays closer to the line, matches up against tight ends, and is more involved in the run, while the free safety typically is farther from the line and plays more of a "last line of defense" role in both the pass and run game.