Tri-Unison by Nick Conticello

Effect: The performer removes three cards from a shuffled deck and leaves them in a face down pile on the table. He explains that these cards are mates of cards that will be selected by two spectators and himself. The two spectators choose numbers freely and the cards at those positions are placed into a separate stack on the table. The magician offers the audience a choice of two different numbers for his cards. Whichever is chosen, the performer counts to that card and places it on top of the first two selections. A spectator turns over the predictions one at a time, the performer turns over the selections one at a time and they match perfectly.

Only one sleight is required.

In addition to the mathematical method, Nick offers a nonmathematical approach that will find favor with all card workers.

This is a great prediction effect that you can do anytime, anywhere, and with any deck, even an incomplete pack.