The Basic Strategy (Thorpe, 1966) gives players a series of rules for how to play given their combination of cards and the dealer’s face-up card. Thorpe worked out an elaborate system to guide the player’s decision in a game of blackjack. For example, if a player has 16, and the dealer has a 10 card showing, the player should draw another card; however, if the dealer has a 6 showing, the player should stand. These rules are based on probabilities and were worked out using computer simulations (for a detailed explanation of the Basic Strategy, see Thorpe, 1966; Wong & Spector, 1996; Patterson, 1990; Ortiz, 1986). The player needs only to memorize—and stick to—the Basic Strategy.

Under ideal circumstances, with a single deck, a player following the Basic Strategy plays against no house edge (see Thorpe, 1966). With a multi-deck game, a player who meticulously follows the rules of the Basic Strategy can achieve a payback percentage as high as 99.5% in ideal circumstances. An exact figure for payback depends on the number of decks in use, the casino rules for the game, and how well the player follows the strategy.

In practice, most blackjack players only partially follow the Basic Strategy (Wagenaar, 1988) and in so doing achieve a return somewhere between 94% and 99%. Many players copy the dealer, standing on 17 and hitting below 17. Other people avoid busting because they know that the house advantage comes mostly from the fact that when both the player and the house busts, the house still wins. Their belief is that, if they avoid busting, even by standing on very weak card totals such as 12 or 13, they can beat the edge, but in fact in some circumstances standing on a 12 decreases the payback percentage. Some people play based on what feels “right.” In interviews we have heard gamblers actually complain that the rules of the Basic Strategy are actually wrong, because they can recall episodes where they lost money following the Basic Strategy or won money not following it. Some players complain that following the rules is a boring way to play.

Card counting is a playing system that tracks the relative numbers of different cards that have been played (high cards vs. low cards) in order to predict which cards are left in the deck. The system takes advantage of the changes in the relative probabilities of the cards remaining in the deck(s) as more cards are dealt. Card counting was used as far back as the eighteenth century to predict which cards were the best bets in the game of faro (see Turner, Howard, & Spence, 2006). It was not until 1962, however, that Thorpe was able to develop and test a comprehensive system using computer simulations of card counting for use in blackjack (see Thorpe, 1966).

As cards are dealt, the relative number of high and low cards remaining in the deck sometimes changes. By random chance, more of the low cards might have ended up in the first half of the deck and more high cards might have ended up in the second half of the deck. If numerous high cards remain in the deck, a stiff hand (e.g., a 10 and a 6) is likely to bust if another card is drawn. When lots of face cards (ten, jack, queen and king) are left in the deck, the player has an advantage over the dealer because the player is free to hit or stand, but the dealer must hit on any total of 16 or less. On the other hand, if a lot of face cards have been dealt, then the remaining cards have relatively fewer face cards and the player is less likely to win. In addition, more aces in the deck provide the player an advantage because the player wins more when he/she scores a blackjack.

Card counting usually requires the player to keep track of the relative number of face cards vs. cards with lower numbers (2, 3, 4, 5 and 6). To run the system, the player keeps a running score based on the cards that have been drawn. A face card or ace is scored as –1 and a lower card is scored as +1. The player bets the minimum amount following the Basic Strategy, but when the card count is in the player’s favour (e. g., +5), the player increases his/her bet. In addition, players can adjust their choices to hit, stand, split or double down based on card-counting information.

An important consideration is that, the player has to run this system in such a way as to not get caught since card counting is considered cheating by the casino. In the past, successful card counters have been banned from casinos for life.

Card counting requires a lot of skills and patience. A player also needs a fairly substantial bankroll in order to withstand the occasional losing sessions that occur by chance. Many card counters work in teams to help each other spot opportunities, increase their available bankroll and reduce the impact of short-term variabilities in the game. To many ordinary players, card counting is a boring way to gamble. I know of a problem gambler who was a fantastic card counter, but would end up losing because he would become too excited or start to feel lucky and stop following the rules. Furthermore, the “house” takes active steps to prevent card counting, including banning suspected card counters, using larger numbers of decks and reshuffling the decks whenever a counter increases his bet (Patterson, 1990). Some casinos have engaged in cheating to ensure that the card counter loses (Thorpe, 1966). Rule changes have made card counting more difficult (Patterson, 1990) and recent developments in gaming technology such as automatic shufflers and computerized dealers may completely eliminate the possibility of card counting.

Back to Games and Systems