In most blackjack versions, when you have two identical cards, you have the option to select split /dividing/. If you choose to split, the two cards are split into two separate standalone hands and your bet doubles. If you beat the dealer on both hands, then you win twice. If one hand is profitable and the other is losing, you are zero-zero. If both hands are losing, you lose both bets. It is wise to split with two aces and two eights. It is not advisable to split with two tens, two queens, two jacks, two kings, two fours, two fives.