Blackjack

Much of blackjack's popularity is due to the mix of chance with elements of skill, and the publicity that surrounds card counting (keeping track of which cards have been played since the last shuffle). Blackjack's precursor was vingt-et-un ("twenty-one"), which originated in French casinos around 1700, and did not offer the 3:2 bonus for a two-card 21.

When blackjack was first introduced in the United States it was not very popular, so gambling houses tried offering various bonus payouts to get the players to the tables. One such bonus was a 10-to-1 payout if the player's hand consisted of the ace of spades and a black Jack (either the Jack of clubs or the Jack of spades). This hand was called a "blackjack" and the name stuck to the game even though the bonus payout was soon abolished. As the game is currently played, a "blackjack" may not necessarily contain a jack or any black cards at all.

Blackjack Rules

Each player is dealt two cards and is then offered the opportunity to take more. The hand with the highest total wins as long as it doesn't exceed 21; a hand with a higher total than 21 is said to bust or have too many. Cards 2 through 10 are worth their face value, and face cards (jack, queen, king) are also worth 10. An ace's value is 11 unless this would cause the player to bust, in which case it is worth 1. A hand in which an ace's value is counted as 11 is called a soft hand, because it cannot be busted if the player draws another card.

The goal of each player is to beat the dealer by having the higher, unbusted hand. Note that if the player busts he loses, even if the dealer also busts (therefore Blackjack favors the dealer). If both the player and the dealer have the same point value, it is called a "push", and neither player nor dealer wins the hand. Each player has an independent game with the dealer, so it is possible for the dealer to lose to one player, but still beat the other players in the same round.

The minimum bet is printed on a sign on the table and varies from casino to casino and even table to table. After initial bets are placed, the dealer deals the cards, either from one or two hand-held decks of cards, known as a "pitch" game, or more commonly from a shoe containing four or more decks. The dealer gives two cards to each player, including himself. One of the dealer's two cards is face-up so all the players can see it, and the other is face down. (The face-down card is known as the "hole card". In European blackjack, the hole card is not actually dealt until the players all play their hands.) The cards are dealt face up from a shoe, or face down if it is a pitch game.

A two-card hand of 21 (an ace plus a ten-value card) is called a "blackjack" or a "natural", and is an automatic winner. A player with a natural is usually paid 3:2 on his bet. Some casinos pay only 6:5 on blackjacks; although this reduced payout has generally been restricted to single-deck games where card counting would otherwise be a viable strategy. The move was decried by longtime blackjack players.

Blackjack Basic strategy

Because blackjack has an element of player choice, players can reduce casino advantage to a small percentage by playing basic strategy. This determines when to hit or to stand, and also determines when to double down or split. Basic strategy is based on the player's point total and the dealer's visible card. There are slight variations depending on the house rules and number of decks.

Card counting:

Basic strategy provides the player with the optimal play for any blackjack situation, based on millions of hands played in the long run. However in the short run, as the cards are dealt from the deck, the remaining deck is no longer complete. By keeping track of the cards that have already been played, it is possible to know when the cards remaining in the deck are advantageous for the player.

Card counting creates two opportunities:

The player can make larger bets when he or she has the advantage. For example, the player can increase the starting bet if there are many aces and tens left in the deck, in the hope of hitting a blackjack. The player can use information about the remaining cards to improve upon the basic strategy rules for specific hands played. For example, with many tens left in the deck, the player may double down in more situations since there is a better chance of making a strong hand. There are several card counting systems which do not require that the player remembers which cards have been played. Rather, a point system is established for the cards, and the player keeps track of a simple point count as the cards are played out from the dealer.

Depending on the particular blackjack rules in a given casino, basic strategy reduces the house advantage to less than one percent [1]. Card counting typically gives the player an advantage of 0.5 to 1.5% over the house.[citation needed] To counter card counting, some casinos play with multiple decks.

In most US jurisdictions, card counting is legal and is not considered cheating. However, most casinos have the right to ban players, with or without cause, and card counting is frequently used as a justification to ban a player. Usually, the casino host will simply inform the player that he is no longer welcome to play at that casino. Players must be careful not to signal the fact that they are counting. The use of electronic or other counting devices is usually illegal and almost always prohibited by the casino.

Composition-dependent strategy

Basic strategy is based on a player's point total and the dealer's visible card. A player's ideal decision may depend on the composition of his or her hand, not just the information considered in the basic strategy. For example, a player should ordinarily stand when holding 12 against a dealer 4. However, in a single deck game, the player should hit if his or her 12 consists of a 10 and a 2; this is because the player wants to receive any card other than a 10 if hitting, and the 10 in the player's hand is one less card available to cause a bust for the player or the dealer. However, in situations where basic and composition-dependent strategy lead to different actions, the difference in expected value between the two decisions will be small. Additionally, as the number of decks used in a blackjack game rises, both the number of situations where composition determines the correct strategy and the house edge improvement from using a composition-dependent strategy will fall. Using a composition-dependent strategy only reduces house edge by 0.0031% in a six-deck game, less than one tenth the improvement in a single-deck game (0.0387%).