Abstract: A novel method and apparatus for determing whether or not a hole card is a member of a blackjack pair without direct observation of the hole card. The cards are separably marked in groups of aces and of face cards and tens. Each mark is detectable by a card mark sensor. The card mark sensor is used to differentially determine whether or not the hole card is a member of predetermined group when a card is placed face down therein. Thus, when the dealer receives a face-up member of a blackjack pair, the hole card is inserted into the sensor and determined to be or not to be the other member of the blackjack pair immediately and without observation of the face of the hole card. If the hole card is the other member of the blackjack pair play is stopped, and the next hand is thereby more quickly started. If the dealer does not have blackjack, play continues without knowledge by either player or dealer of the actual value of the hole card.