McCombical Prediction Deck - Bicycle by Billy McComb
The performer predicts a card by removing it from a red deck and placing it in plain view of the audience.
The participant, seated behind the performer, now must select a card from an entirely different deck - hopefully matching the prediction card. The audience can see that the second deck consists of 52 duplicates of the prediction card.
The participant is now invited to call "stop" as the magician moves the cards one at a time from the top to the bottom of the deck. On the word "stop," that card is given to the participant. The audience is laughing since they can see the prediction and that all the cards in the second deck were the same as the prediction.
The participant calls out the name of the card which they selected and the audience is shocked to hear that the selected card is NOT the same as the prediction! The performer picks up the predicted card and places it beside the chosen card. Magically, when the two cards are turned over they are exact duplicates!
This deck is a complete mystery that is a reputation maker for any performer.