Tackle ( American football position ) Tackle is a playing position in American and Canadian football . Historically , in the one - platoon system a tackle played on both offense and defense . In the modern system of specialized units , offensive tackle and defensive tackle are separate positions . Offensive tackle . The offensive tackle ( OT , T ) is a position of the offensive line , left and right . Like other offensive linemen , their job is to block : to physically keep defenders away from the offensive player who has the football . The term " tackle " is a vestige of an earlier era of football , in which the same players played both offense and defense . A tackle is the strong position on the offensive line . They power their blocks with quick steps and maneuverability . The tackles are mostly in charge of the outside protection . If the tight end goes out for a pass , the tackle must cover everyone that his guard does not , plus whoever the tight end is not covering . Usually they defend against defensive end s . In the NFL , offensive tackles often measure over and . According to " Sports Illustrated " football journalist Paul " Dr . Z " Zimmerman , offensive tackles consistently achieve the highest scores , relative to the other positional groups , on the Wonderlic Test , with an average of 26 . The Wonderlic is taken before the draft to assess each player ' s aptitude for learning and problem solving ; a score of 26 is estimated to correspond with an IQ of 112 . Right tackle . The right tackle ( RT ) is usually the team ' s best run blocker . Most running plays are towards the strong side ( the side with the tight end ) of the offensive line . Consequently the right tackle will face the defending team ' s best run stoppers . He must be able to gain traction in his blocks so that the running back can find a hole to run through . Left tackle . The left tackle ( LT ) is usually the team ' s best pass blocker . Of the two tackles , the left tackles will often have better footwork and agility than the right tackle in order to counteract the pass rush of defensive ends . Most quarterbacks are right - handed and in order to throw , they stand with their left shoulders facing down field , closer to the line of scrimmage . Thus , they turn their backs to defenders coming from the left side , creating a vulnerable " blind side " that the left tackle must protect . ( Conversely , teams with left - handed quarterbacks tend to have their better pass blockers at right tackle for the same reason . ) A 2006 book by Michael Lewis , " " , sheds much light on the workings of the left tackle position . The book discusses how the annual salary of left tackles in the NFL skyrocketed in the mid - 90 ' s . Premier left tackles are now highly sought after commodities , and are often the second highest paid players on a roster after the quarterback ; at least one left tackle is almost always picked with one of the first five positions in the NFL Draft . Recent examples include Matt Kalil ( 2012 , 4th overall pick ) , Trent Williams ( 2010 , 4th overall pick ) , Jake Long ( 2008 , 1st overall pick ) , and Joe Thomas ( 2007 , 3rd overall pick ) . Defensive tackle . A defensive tackle ( abbreviated " DT " ) is typically the largest and strongest of the defensive players . The defensive tackle typically lines up opposite one of the offensive guards . Depending on a team ' s individual defensive scheme , a defensive tackle may be called upon to fill several different roles . These roles may include merely holding the point of attack by refusing to be moved , or penetrating a certain gap between offensive linemen to break up a play in the opponent ' s backfield . If a defensive tackle reads a pass play , his primary responsibility is to pursue the quarterback , or simply knock the pass down at the line if it ' s within arm ' s reach . Other responsibilities of the defensive tackle may be to pursue the screen pass or drop into coverage in a zone blitz scheme . In a traditional 4 - 3 defensive set , there is no nose tackle . Instead there is a left and right defensive tackle . In some 4 - 3 defensive schemes , there is a nose tackle , which lines up against the opposing center . The nose tackle in a 4 - 3 defensive scheme can either be the left or right defensive tackle . Nose tackle . Nose tackle ( also nose guard or middle guard ) is a defensive alignment position for a defensive lineman . In the 3 - 4 defensive scheme the sole defensive tackle is referred to as the nose tackle . In some 4 - 3 defensive schemes , the nose tackle is one of two defensive tackles . The nose tackle aligns across the line of scrimmage from the offense ' s center before the play begins in the " 0 - technique " position . In this position , frequently taking on the center and at least one if not both of the guards , the nose tackle is considered to be the most physically demanding position in football . In five - linemen situations , such as a goal - line formation , the nose guard is the innermost lineman , flanked on either side by a defensive tackle or defensive end . The nose guard is also used in a 50 read defense . In this defense there is a nose guard , two defensive tackles , and two outside linebackers who can play on the line of scrimmage or off the line of scrimmage in a two point stance . The nose guard lines up head up on the center about six to eighteen inches off the ball . In a reading 50 defense , the nose guard ' s key is to read the offensive center to the ball . In run away , the nose guard ' s job is to shed the blocker and pursue down the line of scrimmage , taking an angle of pursuit . The primary responsibility of the nose tackle in this scheme is to absorb multiple blockers so that other players in the defensive front can attack ball carriers and rush the quarterback . In order for a 3 - 4 to be effective , it needs a dominant nose tackle , which is very hard to find . Ted Washington , who in his prime weighed around 350 pounds , is considered the prototypical 3 - 4 nose tackle of his era . A few examples of nose tackles in the NFL are Vince Wilfork , Casey Hampton , Kelly Gregg , Jay Ratliff , Jamal Williams , Kyle Williams , Antonio Garay , B . J . Raji , Aubrayo Franklin , Marcell Dareus , Sione Pouha , Phil Taylor , and Terrence Cody among others . The terms " nose guard " or " middle guard " were more commonly used with the five - man defensive line of the older 5 - 2 defense . Effective against the inside run but not the short pass , the 5 - 2 was phased out of the pro game in the 1950s , but was still used by some major college programs into the 1980s . In the 4 - 3 defense , the upright middle linebacker replaced the middle guard .