Please do not reveal the contents of this manuscript to anyone as this effect is being performed by many well known magicians.
You can do this unbelievable trick easily.
The performer shuffles a borrowed deck of cards, then cuts the pack into 4 or 5 sections and hands them back to the spectators for shuffling. When the shuffling is complete a spectator gathers the shuffled packets together and reassembles the pack.
This done he deals to himself eight cards face down. The performed is nowhere near the cards. The spectator fans the cards towards himself as you emphasise that the cards were shuffled by the audience members themselves. The performer then proceeds to name ALL EIGHT cards that the spectator is holding.
After handing out the cards you positively do not touch them again. No cards added or removed, no stooges, the cards are genuinely shuffled and for the best effect you can even use a borrowed deck. We supply pack of professional bicycle cards.