Hi all.
I use this effect reasonably often but would like a streamlined version. I would be extrememely grateful if somebody would give me the card sequences for a 7 and a 9 card version please.

Here is the effect for anybody who does not have the book.

PRIME CHOICE
12 cards are arranged thus - 10, 5, 7, 2, 3, 8, 11(J), 9, 6, 12(Q), A, 4 - These are arranged face-down, 10 on top.

The volunteer now takes any card from the remainder of the deck and places it on top of the above packet.
He cuts the packet, burying the chosen card in the packet.
The top card is now turned face-up, let's say its a 6.
6 cards are counted from top to bottom of the packet and the new top card is turned face-up, let's say it an 8...
...8 cards are now dealt from top to bottom and the new top card is turned over....etc. etc. etc.
This process continues until only one card remains face-down, the chosen card.

As the title of the effect suggests, it can only be made to work when the total number of cards in the packet (i.e., the original stack plus the selected card) is a prime number. In the published version, the stack has 12 cards: adding the chosen card makes the packet size 13, which is a prime number.

The next lower prime number is 11, yielding a stack size of 10. The following sequence will work: X,8,5,2,10,A,6,3,7,4,9.

The next lower prime number is 7, yielding a stack size of 6. The following will work: X,2,3,6,4,A,5

Fewer cards than that would likely not be interesting.

Many thanks Doug. Stupid of me to ask for a 9-card version, what the heck was I thinking!
The 7-card packet will do nicely however, cheers
Art