This is a great commercial routine from the brilliant Mr .Dobson.
You separate six half cards into two groups under the instructions of the spectator, yet each of the half cards match perfectly.
You now choose a half BEFORE the spectator, and again they match. 
Finally, it all goes wrong, as the two halfs are different. 
However, when your prediction, which has been on the table since the beginning of the effect is revealed, IT MATCHES THE TWO ODD HALVES PERFECTLY ! 

Included:
Self Working Effect with laminated cards
DVD Instructions