46 defense The 46 defense is an American football defensive formation . The formation comprises four down linemen , three linebacker s , and four defensive back s . The 46 defense was originally developed and popularized by Chicago Bears defensive coordinator Buddy Ryan , who later became head coach of the Philadelphia Eagles and Arizona Cardinals . Today the scheme is currently used on a regular basis by the New York Jets head coach and defensive coordinator Rex Ryan , son of Buddy Ryan . Unlike most defensive formations that take their names from the number of defensive linemen and linebackers on the field ( i . e . the 4 - 3 defense has 4 linemen and 3 linebackers ) , the name " 46 " originally came from the jersey number of Doug Plank , who was a starting safety for the Bears when Ryan developed the defense , and typically played in that formation as a surrogate linebacker . Description . The 46 defense was an innovative defense with a unique defensive front , designed to confuse and put pressure on the opposing offense , especially their quarterback . A hyper - aggressive variant of the 4 - 3 base set , the 46 dramatically shifted the defensive line to the weak side ( the opposite end from the offense ' s tight end ) , with both guards and the center " covered " by the left defensive end and both defensive tackles . This front forced offenses to immediately account for the defenders lined up directly in front of them , making it considerably harder to execute blocking assignments such as pulling , trapping and pass protection in general . Moreover , the weak side defensive end would be aligned one to two yards outside the left offensive tackle , leaving opposing tackle ' on an island ' when trying to block the pass rush . Another key feature of the 46 is that both outside linebackers tend to play on the strong side of the formation . To avoid confusion , the strong and weak side linebackers ( who are no longer lined up on opposite sides ) are often renamed the ' Jack ' and ' Charley ' linebackers , respectively . The linebackers line up behind the linemen somewhere between one and three yards from the line of scrimmage . The primary tactic is to rush between five and eight players on each play , either to get to the quarterback quickly or disrupt running plays , although dropping some players back into pass coverage after seemingly indicating that they will blitz ( see zone blitz ing ) is another method of creating confusion . Ryan would use all of these rushers to out - man and overwhelm the offense . Another major key to the 46 is the ability of the cornerbacks to play man free and bump and run coverage . Bump and run can allow the defense to take away the quarterback ' s immediate decision - making ability , by disrupting the timing of short routes needed to make a quick throw to beat the 46 defense . The formation was very effective in the 1980s NFL because it often negated a team ' s running game and forced them to throw the ball . This was difficult for many teams at the time because most offensive passing games centered around the play - action pass , a situation that often favored the defense even further with the quarterback lined up to receive the snap from directly behind the center . Currently , the 46 is rarely used in professional and college football ( with the exception of teams led by Buddy ' s sons , the New York Jets coached by Rex Ryan , and the 2010 Cleveland Browns when Rob Ryan was the defensive coordinator ) . This is largely because of the popularity of the West Coast Offense , used successfully by San Francisco 49ers head coach Bill Walsh , and other offensive schemes that rely on short , timed passes from formations with multiple receivers . A minor weakness of the 46 defense can be too many defensive players lining up near the line of scrimmage to blitz , leaving areas open for receivers to catch passes . Also , short , timed passes can be thrown before the players blitzing have a chance to reach the quarterback . Another problem is that most teams do not have enough impact players to run the 46 as effectively as the 1980s Bears , the late 1980s Eagles and the 1993 Oilers did . Those teams fielded some of the best front - seven defenses ever , and included such players as Mike Singletary , Steve McMichael , Richard Dent , Dan Hampton , Clyde Simmons , and Wilber Marshall . The ideas of the 46 defense are more often used in today ' s game by bringing a fourth defensive back ( usually the strong safety ) up closer to the line of scrimmage , as an eighth man in " the box " to help stop the run . Defenses today may also run safety blitzes and corner blitzes at crucial moments without committing wholly to the " 46 " defense . Up front , teams still use the concept of the " T - N - T " front , where defensive linemen are lined up over the center and the two guards . This makes it difficult for the interior linemen to reach any of the linebackers on the second level . Lining up . This is where defensive players would line up against a normal Pro Set offense . When three or more receivers are used by the offense , the defense makes what is called a jayhawk adjustment . The charlie linebacker will step back to where the middle linebacker was in the normal alignment , the middle linebacker will move to where the strong safety was aligned and the strong safety will move out to cover the third receiver . If the offense uses a fourth receiver , the middle linebacker lines up in front of the center and the charlie linebacker would cover the fourth receiver .