The Kruskal Count Card Trick (with two decks)

The cards below were ordered by shuffling two decks of cards and then dealing them out. Click on any card in the first row. Whatever number is on this card move this many cards to the right and click the new card, treating Ace as a 1 and face cards as 5, and wrapping around to the left side of the next row. Repeat from the card just clicked. I magically know that you will (usually) end up on the 'trap' card, indicated by a thick border. The simpler one deck version is successful about 80% of the time. To reshuffle and play again hit the reload button on your browser.

Created by Alex Frieden and Ravi Montenegro.