Car counting is a card game strategy used to determine when a player has a probability advantage. The term is used almost exclusively to refer to the tracking of the ratio of high cards to low cards in blackjack and its derivatives such as Spanish 21, although it is sometimes used to refer to obtaining a count of the distribution or remaining high cards in trick-taking games, such as contract bridge or spades. This article deals only with card counting as it applies to blackjack and its derivatives.