Lockdown by Manoj Kaushal

If someone claimed they could locate a free selection using a borrowed shuffled deck without ever looking at the cards, you'd call them crazy. If they then claimed it's possible because they've learned to track a shuffle using only sound, you'd call them even crazier. Manoj Kaushal must be bloody insane... because that's exactly what he did.

Imagine this... the spectator shuffles the cards face up into face down, takes out any card, flips it over and puts it back anywhere they want. Your back is turned the entire time and after a simple spread, you know exactly what card they chose. The spectator does all the work for you - It doesn't get any easier than that.

No setup
No gimmicks
No key-cards
Use a borrowed and shuffled deck
Your back is always turned
You never look at the cards until you need to reveal their selection
Manoj uses a brilliant principle that will have you screaming "Why didn't I think of that?"