The 46 defense is an American football defensive formation, an eight men in the box defense, with six players along the line of scrimmage. There are two players at linebacker depth playing linebacker technique, and then three defensive backs. The 46 defense was originally developed and popularized with the Chicago Bears by their defensive coordinator Buddy Ryan, who later became head coach of the Philadelphia Eagles and Arizona Cardinals. 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 strong safety for the Bears when Ryan developed the defense, a role typically played in the formation as a surrogate linebacker. The 46 defense is most effective against the two back, two wide receiver sets that many teams commonly used in the 1980s. However, the defensive formation has been rarely used in professional and college football since then as offenses have adapted to use multiple receiver and spread formations to counteract the 46. 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. Compared to a 4–3 base defense, the 46 dramatically shifts 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 the opposing tackle man-on-man 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 'Charlie' 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