Pile of 10
Pile of 15, Pile of 15 and finally Pile of 9.
Puts the ace on top of pile of 10... that's now the 11th card from the back of the pack.
Cuts the 15, hides Ace in the middle of the cut, BUT ZOMG NOT REALLY, 'cos then he just places the second half of the deck back on the first, so it went from
1, 2, 3, 4, ..., 15
to something like
10, 11, 12, 13, 14, 15, 1, 2, ..., 9
Still 15 cards with Ace as a 16th.
Basically, the cards never move away from their predetermined positions.
Watch it again and you'll notice he fiddles about with putting one cut deck on top of another, etc., but the groups 10-Ace-15-Ace-15-Ace-9 still remain. This is in reverse order, so when 'dealing' the deck it goes rather:
9-Ace-15-Ace-...-10
Or, Aces at 10, 26 and 42; which then enables the magic of the continual half and half dealing until ZOMGZ0RZ IS MY CARD, OH MAGICIAN, HAVE MY BABIES!
(, Fri 6 Jul 2012, 20:51, Reply)