Differential pulley the system becomes a simple "gun tackle" with a mechanical advantage of 2. The same principle is used in a differential windlass, where the connected pulleys are replaced by winches. In the above graphic, the four segments of the chain are labelled W, X, Y and Z. The magnitudes of their corresponding forces are "F", "F", "F" and "F", respectively. Assuming that the chain is massless, "F" = 0 because segment X is not supporting any weight. Taking the system at equilibrium, "F" and "F" are equal — if they were not, the lower pulley would freely turn until they
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