Do you have any card magic books? It's hard to see exactly what he's doing while he handles the cards but the main part of the effect uses a standard method. For instance Scarne on Card Tricks has a trick that is done the same way. We can't tell you the method but depending on what resources you have we can try to point you in the right direction.
As @DavidL11229 said, it is hard to see what he is doing with the cards before the dealing... I suspect purposefully. The method is standard with a minor subterfuge. If you know basic card magic, the odds aren't stacked in your favor, but with an even-handed dealing style you too could make your spectator's selection count when it comes to making a prediction. I suspect similar methods are in Scarne on Card Tricks and in multiple sections of Encyclopedia of Card Tricks.