Counting cards is a technique which is used by gamblers of card games to obtain an opportunity by tracking cards which have been played. This gives the player a theory of the importance of cards, that have to be dealt with. Counting cards is an ability that is more advantageous in twenty-one than in other card game.

In blackjack, a gambler is at an advantage when the remaining shoe holds "high cards." High cards should be faces and aces. The counter in the gambling den brings into play such opportunities by placing bigger bets, as and when they occur. A good many adept players use the composition of the shoe to alter their overall plan. Fairly new players occasionally will have problems while trying fast card counting and might be prone to errors, when it comes to handling dealt decks of cards. Chemin de fer card counting is an industry on its own. Millions are made or lost, both by the gamblers and the gambling halls, depending on card counting methods in play.

Technology has made its presence known on card counting too, with improved devices impacting the entire activity. Long-standing players will swear that a card counting scheme of greater complexity is more prone to blunders, negating the increased accuracy permitted by the application of technology. Anyone can discover many techniques for blackjack card counting by visiting web resources devoted to the game. With the game increasing in fame in gambling halls around the world, there are newer techniques being created every other day. One can locate literally a multitude of Web sites giving you tricks on counting cards and the across the board tactic to earn money through twenty-one.