Card counting is a set of blackjack strategies using which the players assign a certain value to a set of cards. Then, they keep a running count and eventually arrive at a true count of the cards. Card counting helps in getting an estimate of the number of cards already dealt and the number of cards left in the deck. This information allows the player to decide on the playing action as well as the amount he should be spending on each bet. Various systems of counting cards exist, so which one do you prefer?