This is a true visual shocker and the ending blows everyone away!
You pull two cards from a deck as you explain you went to a casino the other night to play blackjack. Show the two cards, they are two black 9's. 18...that's what the guy to your right had! Square up the two cards and re-spread them. The two black 9's turn to two red 10's! 20...even better, that's what the guy on your left had. But luckily you were the only magician at the table...you turn the cards over and you are now holding an Ace and King...BLACKJACK!
This precision-made gimmick does all the work! The backs and fronts are shown on every change! A real wonder of card magic.