I have operated these system at work during training. Go get a pulley on an anchor, a rope and do a pull. Pull one foot and see how far your load moves. Now ad an additional pulley to the load (or within the rigging) and do the same thing. In the first example you will see you move 1 foot and you load moves one foot. In the second you will see you move 2 foot and the load moves one.MOguy, you are correct in that you say you do not understand pulleys. The pulley attached to the tree is giving a 2:1 mechanical advantage with the line coming from the winch and back to the vehicle. It would be a change of direction pulley if the cable ran from the winch through the pulley and to an anchor. The key is the cable runs from the vehicle through the pulley and back to the vehicle. Just because the pulley is attached to an anchor does not make it a change of direction only pulley, it can also provide mechanical advantage.
I have a store bought game hoist. It is 3:1. I have done the same experiment with that. Try it and see how things work out.