BERG'S CARD EFFECT
EFFECT: Performer requests a spectator to choose either the red or the black cards, if red to choose Diamonds or Hearts, if black to choose Clubs or Spades. After the suit is selected the spectator is asked to call for any of the thirteen cards of that suit. Performer removes a pack of cards from a case and requests the spectator to shuffle them.
The performer now states that he will cause the selected or called card to vanish from the deck and appear in his pocket, immediately the performer reaches into his trouser pocket and removes the card called for. The pocket is shown to be empty.
THE MYSTERY: The description above is taken directly from The Sphinx. The mystery comes when you read the method because, unfortunately, not all the method is described. The text finishes abruptly leaving some details unrevealed. I presume some copy got lost in the edit. However, here is the method as described.
SECRET: Remove thirteen cards of any suit you wish from a deck, arrange them in order from Ace to King and place them in your right trouser pocket. Now you may force the suit in the usual way, which I presume you are familiar with. Have spectator call for any card of the suit forced. As soon as the card is called remove remove the balance of the pack from the card case and hand it to be shuffled. While the spectator is shuffling the cards your
COMMENTS: And there the explanation finishes. I presume that Berg located the card named and extracted it from the packet, perhaps putting it on top. This is done as the spectator shuffles the deck. He then palms the cards from his pocket, leaving the called card behind, and adds them to the deck. The result being that after a little more shuffling (to mix the forced suit into the other cards) he could show that the named card had vanished and then reproduce it from an otherwise empty pocket.
This is pure speculation but it seems to be the best way forward although it does leave some questions unanswered especially when it comes to giving the spectator a deck with thirteen cards missing
I checked a lot of Joe Berg material and found that he was fond of tricks in which several cards had been removed from the deck prior to the effect. And he has other tricks in which he palmed from a stack hidden in the pocket. At Ask Alexander there is an instruction sheet The Card Mysterious - Joe Berg. It is an any card at any number trick in which a spectator is invited to call out any Heart card. And then any number from 1 to 50. Berg already has duplicate suit of Hearts in his pocket. The spectator deals the chosen number of cards into Berg's hand and Berg merely palms out the named card from his pocket and drops it on top of the dealt heap to reveal the card at the chosen number. There are some similarities to Berg's Card Effect i.e. working with a single suit and having thirteen cards in the pocket.
Berg's magic was usually very practical which is why I'm not inclined to dismiss this particular trick as an unworkable pipedream. Handling a spectator a 39 card deck does seem bold but given that only one person, the shuffler, would notice the discrepancy you might just get away with it. And the clever idea of forcing a suit to narrow down the selection possibilities is worth noting as an early nod in the direction of Ben Harris' Crossroads effect.
One additional idea, and maybe this was in the original text, is to palm the card from the trouser pocket and produce it from the jacket pocket. Or better still load it into a wallet. To prove the card missing from the deck he is asked to remove it. He can't and you produce it from your pocket.
Another idea is to reduce the number of cards that are missing from the deck. If you offer a choice between 1 and 10 when calling for the value of a card, you only need eight cards in the pocket. Add a couple of jokers to the deck and it won't feel quite so light as it did in the original trick.
In another effect Joe Berg had an interesting idea for arranging cards when in the pocket. Instead of stacking them in order, you stack them, with the odd cards on one side of the packet and the even cards on the other side. Both in numerical order. The idea is to make the named card easier to count to.
With only eight cards you might have, say, the 1, 2, 3, 4 of the suit from the top of the packet. And the 5, 6, 7, 8 in numerical order from the bottom of the packet. I think it's a touch worth knowing about.
NOTES: One source I have not checked is David Avadon's The Berg Book. If anyone out there has a copy I'd be delighted to hear about similar material to Berg's Card Effect.