Card counting is an advanced blackjack strategy in which the players aims to gain more information on the cards left in the shoe. With this information, they can work out the probability of the remaining cards appearing in the next hand and wager accordingly.
There are many strategies to counting cards and some are more advanced than others, but the simple principle is that players pay great attention to the cards dealt from the shoe. If the cards dealt are overall ‘bad’ blackjack cards such as twos, threes and fours, the player would up their bet for future hands in the knowledge that the cards left are likely to be ‘good’ cards such as aces and faces. The reverse would also be true. Some players go as far as to mentally tally all of the cards left in the shoe, and so can work out their odds of, for example, receiving an eight in the next hand.
Card counting lowers the casino’s house edge. It is completely legal, though many live casinos will deny service if they suspect a player of card counting. Many have also introduced continuous shuffling machines to their blackjack tables which make it impossible.
In internet blackjack, Random Number Generators are used to decide the card values which appear in the game. The online shoe is virtually ‘reshuffled’ between every hand of blackjack, and every hand begins with a full 52 card deck in the shoe – in short, the past hands have no impact on the cards in future hands. Thus, when playing blackjack on the web, card counting is often impossible.