Good answer!

Just for fun,

https://youtu.be/2-t5UmvNJxI

Lovely performance, Barry. And I like the ending!

Late to the party, but I would use an old Max Maven ploy.

Pick a number between 10 and 20....
20...
Okay, we will use the top 20 cards.....
You, pick a different number between 10 and 20.....
If they second person picks 10, you are done. Any other number go through the normal procedure.

OK, interesting, but if the first spectator says 20, you CANNOT count these 20 cards individually in a pile on the table because this will reverse their order; you must count the 20 cards in your hand and NOT by reversing the order.

Thanks!

Best regards

I haven't worked out all the details, but I'm sure this would work. Set your force card (the 10S) nineteenth from the top. In other words, put nine indifferent cards on top of the usual setup. When you begin the trick, spread and catch a break below the top nine cards. Ask for "Any two-digit number below thirty." If they pick a number below twenty, double or triple cut to the break (or perform a pass). If they name nineteen, immediately drop the break and use your good luck to your advantage.

However, if they name a two-digit number between twenty and thirty, close the break and proceed as usual.

Hopefully, you get the idea. This little addition expands the options from ten to twenty different two-digit numbers. This seems much fairer and less restrictive.

When I have time, I'll figure out the exact method for retaining the stack and publish it on a secret page on my blog.

Barry, that performance was delightful. As a father of three young girls, I can't think of a better kicker than producing a rainbow! The only thing I'd add would be a pot of gold on the final card (a la "Shenanigans" by Aldo Colombini) and maybe the production of an origami unicorn, a la Blade Runner! Thank you for sharing your beautiful performance.

Marty