Blackjack is the most popular card game in casinos throughout the world. The game is an American creation in its present form, although it has origins in European games such as the French vingt-un (translated as “twenty-one”) and the game trente et quarante (or “thirty-one”) as well as the English game of pontoon. The form of twenty-one used in the United States was modified in 1912 when play at some card rooms in Indiana added an additional three-to-two payoff for winners who had a “natural twenty-one,” that is, a twenty-one count on their first two cards.
The popularity of the game was greatly enhanced by the publication of Dr. Edward O. Thorpe’s book, Beat the Dealer, in 1962 (see Annotated Bibliography). The book presented solid evidence that with proper playing techniques and structures, the odds for this game can actually change and be in the favor of the player.
Blackjack is a house-banked game in which a house dealer seeks to have cards valuing 21 or a number closer to 21 (without being over 21), but higher than the values of cards held by players. The player makes an initial bet according to the house limits. A dealer gives two cards (one at a time) to each player and also takes two cards himself or herself. The blackjack table may accommodate up to seven players, each of whom individually competes with the dealer. The object of the game is to get cards totaling 21. The cards from 2 through 10 count as their number value. The jack, queen, and king each count as 10 points. An ace may count as 1 or as 11. If a hand has a value of 22 or more it is a “bust,” a losing hand for a player, and in most cases for the dealer as well. Although there are variations, in general the two player cards are dealt face up, whereas one dealer card is dealt down and one face up. The player may ask for additional cards in hopes of getting a 21, or closer to 21 than the dealer’s hand. If an extra card makes the player’s hand go to 22 or over, however, the player immediately loses the hand, regardless of what happens to the dealer’s hand. A player who is satisfied with the hand’s value and has not “busted” indicates that he or she wants no more cards. After all players are done taking cards, the dealer exposes the facedown (or hole) card. He or she takes extra cards if that total is 16 or less but stands (that is, takes no more cards) if the value of the cards is 17 or more. In some casinos, a dealer will take more cards when he or she has a value of 17, which includes an ace that is counted as an 11. (This is called hitting a soft 17).
A gambling table before opening hours in a Santa Domingo casino.
Winners are paid at even money; if they bet $5, they win $5, a return of $10. If both the player and the dealer have hands with the same value, it is a tie, and the player’s bet is returned to him or her. A player who busts loses even if the dealer later busts in the same hand.
The situation is altered if the player or the dealer has a natural blackjack. A natural blackjack consists of an ace and a card valued at 10 (10, jack, queen, or king). If the player’s first two cards are a blackjack, he or she wins and is paid three to two; that is, a win of $7.50 plus $5, or a return of $12.50. This win is negated if the dealer also has a two-card blackjack, in which case the play is a tie. If the dealer has a blackjack, he or she beats all players who do not also have a blackjack. In the case of a dealer showing an ace or a 10-value card, the dealer looks at his other card; if it makes a blackjack, he or she reveals it and collects the bets from the losing players without giving them the opportunity to draw cards. If the dealer is showing an ace, however, he or she first offers all players a chance to make insurance bets, which are described later.
Certain special plays and bets are allowed to the players. For instance, if both of the player’s first two cards are the same, he or she may split them into two hands by making an equal bet on the second hand. Some casinos also allow resplitting. New Jersey casinos and many in other jurisdictions, Nevada excluded, allow the player to make a “surrender” play. After the player looks at the dealer’s one card and his or her own two cards, the player may forfeit the hand immediately for only half of the original bet. The player may also like the situation so much that he or she doubles the bet. After “doubling down,” the player may be given only one more card—if he or she desires more cards. Some casinos allow a player to double down if showing cards with values of 10 or 11. Other casinos allow any player to double down.
If the dealer is showing an ace, the player may make a bet called “insurance.” This is a side bet that does not affect the main bet on the value of the player’s and dealer’s hands. The player bets up to half of his or her original bet and wins a two-to-one payoff if the dealer reveals that he or she has a natural blackjack. With this side bet, the casino has an 8 percent edge over the player, as there are sixteen ten-valued cards (which can make the insurance bet a winner) and thirty-six other cards.
The casinos may use from one to eight decks of cards for play at blackjack. As players use strategies that may depend in part upon the cards that have already been bet (counting strategies), some players like single-deck blackjack. This is a game dealt from the dealer’s hand with both of the player’s cards being dealt face down. Most casinos shy away from single-deck games as hand dealing introduces opportunities for cheating and hence requires more monitoring. In multideck games, the cards are dealt from a shoe. A shoe is a box, usually plastic, into which the shuffled decks of cards are placed. They are dealt as the dealer slides cards from one end of the box through an opening. Shoes are also used with baccarat games and other card games.
The popularity of blackjack derives from the fact that, in addition to allowing a strategy that can give the player the edge, the game is a simple game in concept but also allows for very personal strategies. As a variety of strategies and playing styles is used by players, it is not possible to assess the odds-advantage possessed by the house (casino). In one strategy, the player seeks simply never to bust. Hence, he or she stands on any cards giving him or her a value of twelve or more, regardless of the card shown by the dealer. Under this strategy, the casino has a 6.35 percent edge over the player. If the player instead mimics the rules followed by the dealer—taking cards when he or she has a sixteen or less and holding on seventeen or more, then the casino’s edge is reduced to 5.90 percent. A more complicated, but more effective, strategy called “basic blackjack strategy” can reduce the house edge to below 1 percent, and to even, or a slight player edge, with a single-deck game. With properly executed card counting (the Thorpe strategy), the player can gain a 1 or 2 percent edge over the house.