Quite some time ago I developed an effect of this type. It was accepted as being “good” and at the time I had a lot of fun with it in front of magicians and card men. Later I worked out the following in order that I could present the problem in front of a group rather than before very few at a card table.

Anyone is asked forward to stand on your right. He looks over the deck to see that it is well mixed and you explain that he is to have five of the cards in his side coat pocket. He is to take any one of them out and show it to the audience while the performer’s back is turned. Then he is to replace it somewhere among the others, bring out the entire pack and hand it to the performer. The performer places the five cards in his pocket and remarks that through some strange sense of direction he is able to repeat the spectator’s moves. He reaches into his pocket and takes out the same selected card!

In your pocket at the start you have four duplicates of one card, say the Ace of Spades. Use the deck for any other tricks. Then have the spectator forward. Fan through the cards to show them mixed (also letting him see they are not prepared), and locate the regular Ace of Spades which you cut to the top. Give the deck a dovetail shuffle and leave four more cards on top of this. Now explain the procedure. Run off four cards from the top of the deck and tell him that he will put five cards into his pocket without showing them. You put these four cards in a bunch into your pocket on the end so as not to mix them with the others. Now pull out one of these four cards and show it. Then replace it, immediately bringing out the packet of four duplicates which you drop on top of the deck. That leaves five duplicates now on top. Give the deck another dovetail shuffle not disturbing these five and deal them face down into the spectator’s right hand, whereupon he pockets them. Then he pulls out any one and shows it while the performer’s back is turned. Then he puts it back anywhere and brings out the packet which the performer takes with his right hand. The deck has been placed aside or on the table.

The performer puts these five cards in his pocket on their sides. Now, after remarking about the sense of direction, you reach in and take out one of the duplicates. Holding it with its back to the audience, you ask the name of the chosen card. Then you turn your card to show it the right one.

At once you reach into your pocket and remove the four different cards, throwing the five onto the table with the deck which now may be examined or used as it is perfectly unprepared and complete.