Card counting is a casino card game strategy, primarily employed in the game of blackjack, that allows a player to keep a tally on the cards visible during play in order to determine whether further hands in play will be an advantage to the player, or to the dealer.
Most common methods of card counting are based on the statistical premise that certain high cards are an advantage to the player, while certain low cards are an advantage to the dealer. Knowledge of where these cards are likely situated in the deck, and the hands at play, is usually determined using a system of point scores assigned to each card. This allows the tracking of their values in a process called a “running count”.
Card counters are considered to be a class of “advantage player”. These are gamblers who basically attempt to reverse the house edge, the inherent built-in advantage of all casino games.
While technically it is not illegal to card count, and those with the motivation and know-how to use it are fairly rare, casinos nonetheless frown very heavily upon it, and generally reserve the right to ban or expel players caught using it from their establishment.
Though not the first, American mathematician Edward O. Thorp is largely considered to be the father of card counting. In 1962 he published a book called “Beat the Dealer”, which detailed a number of strategies for advantage play in online blackjack NZ, which included the “10-count” system, an early card counting method. Many of the systems described in Thorp’s book have since been made redundant by countermeasures put in place by casinos over the years.
Card counters that came slightly before Thorp, however, include Jess Marcum, credited with inventing the first “point-count” system, Joe Bernstein, a card counter once feared by casinos across Nevada, and an infamous group, dubbed “The Four Horsemen”, composed of Roger Baldwin, Wilbert Cantey, Herbert Maisel, and James McDermott, who published a book in 1957, called “Playing Blackjack to Win” which detailed the first accurate blackjack basic strategy and a rudimentary card counting system.
Perhaps more common than individual card counters, are group counters, where teams of players work together to maximise their advantage, and then later on, share the spoils.
This popular system was made infamous by the MIT blackjack team, whose notorious exploits became the subject of a number of books, as well as the 2008 Hollywood film “21”.
Many card counting devices have been invented and marketed over time, for a variety of uses. However, while using the mind to count cards is not strictly illegal, using a device is, and many card counters employing such devices have been caught, and either received heavy fines or even jail time.
Contrary to folklore, card counting does not necessarily require exceptional mental or mathematical abilities, but rather an exceptional knowledge of the system in use.
Nor do card counters keep track of every single card in the deck, a myth that was propagated by the 1988 fictional Hollywood film “Rain Man”, about a mathematical savant.