The observation test

You can use any deck for this trick. The spectator can shuffle it.

Start by asking the spectator to choose a card and remember it. Put it back on top and control it to the bottom, using an overhand shuffle for example.

Now, without showing the deck face-up to the spectator, select 4 cards of a kind, the four 4 for example. Put them on top of the deck, and re-arrange them in the order you want, while grabbing a pinky break under the spectator's card.

Take these 5 cards and put the rest of the deck on the side. Say to the spectator you will now do a "warming" for the test, and that they have to look closely at the cards.

Grab the bottom card and place it on the table. Do that again with the second to bottom card. Now, do a bottom glide and grab the 2-top cards (a 4 and the spectator's card). You can finally place the last card on top.

You should now have 5 cards with the middle one being the spectator's one.

Now repeat the same thing as before for the "real test" : take the 2 bottom cards first, then the 2 top cards (which will be two 4 this time). You should have the spectator's card in your hands.

Put the 4 back in the deck and cut it to lose them. Now ask what was the last card (the one you supposedly have in your hands). Reveal finally the spectator's selected card.