Card counting is an ability which is employed by gamblers of card games to realize an edge by following cards that have been used. This gives the gambler a theory of the importance of cards, which need to be dealt with. Card counting is a technique that is more useful in black jack than in other card game.

In vingt-et-un, a player is at an advantage when the remaining shoe has "big value cards." Big value cards should be 10s or aces. The counter in the gambling hall takes advantage of these circumstances by laying bigger bets, as and when they occur. Most knowledgeable gamblers use the makeup of the deck to change their overall strategy. Inexperienced players sometimes have difficulty while engaged in rapid card counting and may be subject to errors, when it comes to dealing with dealt decks. Twenty-one card counting is an enterprise on its own. Millions are won or spent, by both the gamblers and the gambling dens, depending on card counting strategies in use.

Computing has made its impact on card counting too, with improved devices affecting the entire process. Old guard gamblers however attest that a card counting plan of greater complexity is more subject to breakdown, canceling out the additional accuracy enabled by the application of computers. Anyone can locate many schemes for blackjack card counting by visiting online pages committed to blackjack. With the game increasing in acceptance in casinos all over the world, there are newer game plans coming up every other day. One can locate literally a multitude of Web sites providing you ways on card counting and the across the board plan to earn money playing chemin de fer.