This is the trick that I get nervous watching every time. Even when it's my own recorded performance of it. The method is crazy risky. It didn't work during my dress rehearsal.
There is no deck swap. It's a normal deck.
Though the method is mine, credits to Ricky Jay and his infamous card manipulation for the plot of this trick. Also, credit goes to Stephen Fry for other patter ideas and introducing me to factorials.
Forgive the video quality. This is the best version I got. Crowd was around 5 or 6 hundred.
(I won the talent show. Yippee!)