The Hole-Carding technique refers to obtaining information that should normally be hidden in card games such as Blackjack, Three Card Poker and Caribbean Stud. If no use is made of a mirror or touching the cards, for example, Hole-Carding is considered legal form in most jurisdictions. In Blackjack, if a player knows about the dealer’s Hole Card, they can get a theoretical 13% lead instead of the casino having a 0.5% lead.
In casinos where the card is only dealt to the dealer at the end, it is not possible to know the bottom of the card. With Hole-Carding you need more players. Often one player sits on the far right, as close as possible to the shoe from which the cards are dealt by the dealer. When the dealer takes the card out of the shoe, the “advantage gambler” knows exactly how to know the value of the card at a glance. They are trained in this and it requires a lot of practice.