Show your spectator a pair of matching Bicycle decks. Put both decks in your pocket, and let your spectator name ANY number between 1 and 52. Take one of the decks out of your pocket. The deck has a label on it that says "Prediction". Remove the cards from the box, and count down to the spectator's number. Place the chosen card face down on the table.
Next, explain that your favorite number is 13. Remove the other deck from your pocket- the box has a label on it that says "Thirteen". Remove the cards from that box, and count down to the 13th card. Place that card face down on the table next to your spectator's card.
When the two chosen cards are turned face up- THEY MATCH!
We can't say enough about this GREAT effect! Peter Monticup carries it with him now wherever he goes- it BLOWS THEM AWAY!