The magician slowly drops the cards from one hand to another an asks the spectator when to stop. When "stop" is said the magician stops dropping the cards and shows the sepctator the last dropped card, which happens to be the magicians pre-selected card.
Shuffle the deck and get a glimpse of the top card (this is the force card). Give the cards one last cut and hold a Pinky Break above the original top card. This cut should make the force about a third from the top of the deck. Slowly let the cards dribble from one hand to another, once the spectator says "stop", drop the rest of the cards under the break and show the spectator the last dropped card (the force card).