Cards you will need: Robbin Goblin, White Magical Hat, and the Inexperinced spy.

On the field have a monster that can wipe out a monster on your opponents side of the field so Hats can attack his/her LP. With Goblin already on the field play the spy and select a card to take a look at. Attack his LP and if the spy chose a good card to look at discard that card and discard another one. If it is a bad card just take a good guess and pick two more. I hope this works for you guys.