Finding by Geni

Imagine with a normal deck, you let spectator to cut a small pile (about 10-15 cards) and cut a big pile (about 20-35 cards). They freely chose any random card.
Without peeking , and no using any gimmick
Just use your feeling you will find out exatcly spectator's card.
+ Normal deck
+ No gimmick
+ No force
+ Self working
+ Work 100%
+ Easy to do