In this particular version of the 21 cards you are faced with a really subtle principle that will leave even the most experienced magicians speechless.
This is a version of the 21-card effect that you can share with your fellow magicians. Joseph B. used it a lot when he was working in the magic shop of Turin. This is certainly a routine indicated to fool magicians because at each step it eliminates every possible explanation one by one. Unlike the classic effect, there is no need to ask the spectator which row the card is in. You can borrow the spectator’s deck.
Normal DECK of cards
Borrowed Shuffled deck