Differential pulley load, and an endless rope looped around the pulleys. To avoid slippage, the rope is usually replaced by a chain, and the connected pulleys by sprockets. The two sections of chain carrying the single pulley exert opposing and unequal torques on the connected pulleys, such that only the "difference" of these torques has to be compensated manually by pulling the loose part of the chain. This leads to a mechanical advantage: the force needed to lift a load is only a fraction of the load's weight. At the same time, the distance the load is lifted is smaller than 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