Lennart Green 13 with 2 decks

By Team Trick Collector
Classic with 2 decks & secret.
The logic is  ACAAN related.
4 suits x 13 =52





Performance

and explanation visualized (VIDEO) 

and the secret revealed (MATH)

Suppose you start with 3 cards x, y and z.

Then the 1st pile has 13-x+1 cards. The 2nd pile has 13-y+1 and the 3rd 13-z+1.

So, the number of cards in the 3 piles is 13-x+1+13-y+1+13-z+1 = 42-(x+y+z) ⟺

The number of cards not in the 3 piles is 52-(42-(x+y+z) = 10 + (x+y+z) ⟺

When you put away 10 cards the remainder is x+y+z