There is a natural tendancy to power an attack (forward movement) but not so when withdrawing (movement towards oneself). In the, the outgoing upper half is often naturally powered. The second half of the second, the way back towards your own center is often not powered. Power must be present at all times during the process of the circle: positive or negative. The powering of the entire circle is like this: Outgoing with rear foot and incoming with front foot.