The line consists of two tackles and two ends. The tackles line up usually somewhere between directly opposite the offensive guards and the center; rarely will they be outside the guards. Their job is to control their assigned gaps on run plays and pressure the quarterback on passes. The ends line up on the outside shoulder of the widest offensive lineman; their main responsibility is to turn running plays back inside to the linebackers and defensive backs (in order to contain the run). They occasionally have pass coverage responsibilities and depending on personnel and scheme, may cover split ends and slot receivers. Some teams designate their best contain man to always play the wide side of the field.