This is a GAG Card and you can use it in different ways in your show.
Put the GAG card face down over the table and tell to the spectator that it is your prediction. Give the deck of the cards to another spectator and asks to choose a number between 10 and 20. Count the number of the cards that represents the chosen number (Putting one card over the other). Then tell the spectator to give the cards for two players alternating the cards. Now you have two piles of cards and the top card of each pile will determine your prediction. You can say that you feel that the top cards have the same suits and the result of the summary of those cards will match with your prediction. While revealing the cards pretend that there is something wrong, but we know that a magician never fails…and show the prediction.