Counting cards is a technique that is used by gamblers of card games to realize an opportunity by tracking cards that have been used. This provides the gambler a notion of the value of cards, which need to be dealt with. Counting cards is a technique that has more use in 21 than in other card game.

In 21, a gambler is at an advantage when the remaining shoe houses "high cards." High cards could be faces or aces. The card counter in the gambling hall takes advantage of such opportunities by placing larger bets, as and when they happen. A great many knowledgeable gamblers use the composition of the deck to alter their overall plan. Fairly new players on occasion have difficulty while engaged in rapid card counting and may be subject to errors, when it comes to dealing with dealt decks of cards. Blackjack card counting is a business by itself. millions and millions are made or spent, both by the players and the casinos, based on card counting tactics in use.

Computing has made its impact on card counting too, with improved computing power affecting the complete process. Long-established gamblers will swear that a more complicated card counting plan is more subject to error, evening out the added accuracy permitted by the use of computers. Anyone can find many schemes for blackjack card counting by visiting internet pages committed to black jack. With the game increasing in fame in gambling halls around the globe, there are better plans being developed every other day. One can find literally hundreds of internet pages giving you hints on card counting and the overall scheme to earn money playing twenty-one.