a card game strategy (e.g. blackjack) in which a player keeps a mental tally of the cards played in order to calculate the probability of certain cards being dealt, therefore obtaining an advantage
Card counting is sometimes used to obtain a count of the distribution or remaining high cards in trick-taking games, such as contract bridge or spades.
also card counter , (n.)
I was touring the film festival circuit with my latest film, Holy Rollers: The True Story of card counting Christians.