Um I don't think that's the right name for it but it's as good as any. The affect is basically this, you have 2 cards, one with yes written on it and one with no. Whatever your presentation is you place one card on the table face down and hold onto the other. Ask the spectator what it is and he's either always right or always wrong (depending on your presentation.)
I came up with a way to do this with folded billets but I was just wondering if there was a method out there (a full proof one) using cards where the spectator can pick up the card.
I don't see anything special about this trick anyway. It is a 50-50 chance she will pick the correct one. Unless you plan on doing it 4 or 5 times in a row.
So you place one card down on the table and you want the spec to guess if it is yes or no? There is really no clean way to do this unless you verbally force them, which won't always work. Besides that, there is no real clean way to do it unless you do a switch. But I am assuming you would like for the spectator to turn it over himself?
You could place it in an envelope and have a two way out envelope. Or you could have a double backer with Yes on one side and No on the other in the envelope. Again, not as clean as you would like...