Counting cards at Blackjack is a learned skill and frowned upon by casinos. The reason the player is feared who can do this with skill and discipline is simple. It puts the odds in the player's favor.

Card counting is a skill which is used by players of card games to gain an advantage by tracking cards which have been played. This gives the player an idea of the value of cards, which need to be dealt with. Card counting is a skill that is more useful in blackjack than in other card games.