Mechanical advantage assembly of a rope and pulleys that is used to lift loads. A number of pulleys are assembled together to form the blocks, one that is fixed and one that moves with the load. The rope is threaded through the pulleys to provide mechanical advantage that amplifies that force applied to the rope. In order to determine the mechanical advantage of a block and tackle system consider the simple case of a gun tackle, which has a single mounted, or fixed, pulley and a single movable pulley. The rope is threaded around the fixed block and falls down to the
Off-tackle run ball carrier. The Maryland I used the 2nd back to lead through the hole and block the linebacker. More complicated versions of the play have pulling guards block the linebacker or combination blocks by a tight-end and tackle to create the hole and block the linebacker. The off-tackle play is a key feature of the single wing offense. Off-tackle run An off-tackle run in American football is a play in which the running back carries the ball through a running lane off of the tackle's block. The lead block kicks out the end man on the line of scrimmage, and