After a bust or a stand, play proceeds to the next hand clockwise around the table. When the last hand has finished being played, the dealer reveals the hole card, and stands or draws further cards according to the rules of the game for dealer drawing.
When the outcome of the dealer's hand is established, any hands with bets remaining on the table are resolved usually in counterclockwise order: If the dealer's upcard is an ace, the player is offered the option of taking "insurance" before the dealer checks the hole card.
Insurance is a side bet that the dealer has blackjack and is treated independently of the main wager. The idea is that the dealer's second card has a fairly high probability nearly one-third to be ten-valued, giving the dealer blackjack and disappointment for the player.
It is attractive although not necessarily wise for the player to insure against the possibility of a dealer blackjack by making a maximum "insurance" bet, in which case the "insurance proceeds" will make up for the concomitant loss on the original bet.
The player may add up to half the value of their original bet to the insurance and these extra chips are placed on a portion of the table usually marked "Insurance pays 2 to 1".
Players with a blackjack may also take insurance, and in taking maximum insurance they commit themselves to winning an amount exactly equal to their main wager, regardless of the dealer's outcome.
Fully insuring a blackjack against blackjack is thus referred to as "taking even money", and paid out immediately, before the dealer's hand is resolved; the players do not need to place more chips for the insurance wager.
Insurance bets are expected to lose money in the long run, because the dealer is likely to have blackjack less than one-third of the time. However the insurance outcome is strongly anti-correlated with that of the main wager, and if the player's priority is to reduce variation , they might choose to pay for this.
Furthermore, the insurance bet is susceptible to advantage play. It is advantageous to make an insurance bet whenever the hole card has more than a chance of one in three of being a ten.
Advantage play techniques can sometimes identify such situations. In a multi-hand, face-up, single deck game, it is possible to establish whether insurance is a good bet simply by observing the other cards on the table after the deal; even if there are just 2 player hands exposed, and neither of their two initial cards is a ten, then 16 in 47 of the remaining cards are tens, which is larger than 1 in 3, so insurance is a good bet.
This is an elementary example of the family of advantage play techniques known as card counting. Bets to insure against blackjack are slightly less likely to be advantageous than insurance bets in general, since the ten in the player's blackjack makes it less likely that the dealer has blackjack too.
The rules of casino blackjack are generally determined by law or regulation, which establishes certain rule variations allowed at the discretion of the casino.
The rules of any particular game are generally posted on or near the table, failing which there is an expectation that casino staff will provide them on request.
Over variations of blackjack have been documented. As with all casino games, blackjack incorporates a "house edge", a statistical advantage for the casino that is built into the game.
The advantage of the dealer's position in blackjack relative to the player comes from the fact that if the player busts, the player loses, regardless of whether the dealer subsequently busts.
The loss rate of players who deviate from basic strategy through ignorance is generally expected to be greater. Surrender, for those games that allow it, is usually not permitted against a dealer blackjack; if the dealer's first card is an ace or ten, the hole card is checked to make sure there is no blackjack before surrender is offered.
This rule protocol is consequently known as "late" surrender. The alternative, "early" surrender, gives player the option to surrender before the dealer checks for blackjack, or in a no-hole-card game.
Early surrender is much more favorable to the player than late surrender. Most medium-strength hands should be surrendered against a dealer Ace if the hole card has not been checked.
For late surrender, however, while it is tempting to opt for surrender on any hand which will probably lose, the correct strategy is to only surrender on the very worst hands, because having even a one in four chance of winning the full bet is better than losing half the bet and pushing the other half, as entailed by surrendering.
With no hole card, it is almost never correct basic strategy to double or split against a dealer ten or ace, since a dealer blackjack will result in the loss of the split and double bets; the only exception is with a pair of A's against a dealer 10, where it is still correct to split.
In all other cases, a stand, hit or surrender is called for. For instance, holding 11 against a dealer 10, the correct strategy is to double in a hole card game where the player knows the dealer's second card is not an ace , but to hit in a no hole card game.
The no hole card rule adds approximately 0. The "original bets only" rule variation appearing in certain no hole card games states that if the player's hand loses to a dealer blackjack, only the mandatory initial bet "original" is forfeited, and all optional bets, meaning doubles and splits, are pushed.
Each blackjack game has a basic strategy , which is playing a hand of any total value against any dealer's up-card, which loses the least money to the house in the long term.
An example of basic strategy is shown in the table below, and includes the following parameters: The bulk of basic strategy is common to all blackjack games, with most rule variations calling for changes in only a few situations.
For example, if the above game used the hit on soft 17 rule, common in Las Vegas Strip casinos, only 6 cells of the table would need to be changed: A, surrender 15 or 17 vs.
A, double on A,7 vs. Also when playing basic strategy never take insurance or "even money. Estimates of the house edge for blackjack games quoted by casinos and gaming regulators are generally based on the assumption that the players follow basic strategy and do not systematically change their bet size.
Most blackjack games have a house edge of between 0. Casino promotions such as complimentary matchplay vouchers or 2: Basic strategy is based upon a player's point total and the dealer's visible card.
Players may be able to improve on this decision by considering the precise composition of their hand, not just the point total. For example, players should ordinarily stand when holding 12 against a dealer 4.
However, in a single deck game, players should hit if their 12 consists of a 10 and a 2. The presence of a 10 in the player's hand has two consequences: However, even when basic and composition-dependent strategy lead to different actions, the difference in expected reward is small, and it becomes even smaller with more decks.
Using a composition-dependent strategy rather than basic strategy in a single deck game reduces the house edge by 4 in 10,, which falls to 3 in , for a six-deck game.
Blackjack has been a high-profile target for advantage players since the s. Advantage play is the attempt to win more using skills such as memory, computation, and observation.
These techniques, while generally legal, can be powerful enough to give the player a long-term edge in the game, making them an undesirable customer for the casino and potentially leading to ejection or blacklisting if they are detected.
The main techniques of advantage play in blackjack are as follows:. During the course of a blackjack shoe, the dealer exposes the dealt cards.
Careful accounting of the exposed cards allows a player to make inferences about the cards which remain to be dealt.
These inferences can be used in the following ways:. A card counting system assigns a point score to each rank of card e. When a card is exposed, a counter adds the score of that card to a running total, the 'count'.
A card counter uses this count to make betting and playing decisions according to a table which they have learned.
The count starts at 0 for a freshly shuffled deck for "balanced" counting systems. Unbalanced counts are often started at a value which depends on the number of decks used in the game.
Blackjack's house edge is usually between 0. Card counting is most rewarding near the end of a complete shoe when as few as possible cards remain.
Single-deck games are therefore particularly susceptible to card counting. As a result, casinos are more likely to insist that players do not reveal their cards to one another in single-deck games.
In games with more decks of cards, casinos limit penetration by ending the shoe and reshuffling when one or more decks remain undealt.
Casinos also sometimes use a shuffling machine to reintroduce the exhausted cards every time a deck has been played. Card counting is legal and is not considered cheating as long as the counter is not using an external device, : Sometimes a casino might ban a card counter from the property.
The use of external devices to help counting cards is illegal in all US states that license blackjack card games.
Techniques other than card counting can swing the advantage of casino blackjack toward the player. All such techniques are based on the value of the cards to the player and the casino as originally conceived by Edward O.
Shuffle tracking requires excellent eyesight and powers of visual estimation but is more difficult to detect since the player's actions are largely unrelated to the composition of the cards in the shoe.
Arnold Snyder's articles in Blackjack Forum magazine brought shuffle tracking to the general public.
His book, The Shuffle Tracker's Cookbook, mathematically analyzed the player edge available from shuffle tracking based on the actual size of the tracked slug.
Patterson also developed and published a shuffle-tracking method for tracking favorable clumps of cards and cutting them into play and tracking unfavorable clumps of cards and cutting them out of play.
The player can also gain an advantage by identifying cards from distinctive wear markings on their backs, or by hole carding observing during the dealing process the front of a card dealt face down.
These methods are generally legal although their status in particular jurisdictions may vary. Many blackjack tables offer a side bet on various outcomes including: The side wager is typically placed in a designated area next to the box for the main wager.
A player wishing to wager on a side bet is usually required to place a wager on blackjack. Some games require that the blackjack wager should equal or exceed any side bet wager.
A non-controlling player of a blackjack hand is usually permitted to place a side bet regardless of whether the controlling player does so.
The house edge for side bets is generally far higher than for the blackjack game itself. Nonetheless side bets can be susceptible to card counting.
A side count, designed specifically for a particular side bet, can improve the player edge. Only a few side bets, like "Lucky Ladies", offer a sufficient win rate to justify the effort of advantage play.
In team play it is common for team members to be dedicated toward counting only a sidebet using a specialized count.
Blackjack can be played in tournament form. Players start with an equal numbers of chips; the goal is to finish among the top chip-holders.
Depending on the number of competitors, tournaments may be held over several rounds, with one or two players qualifying from each table after a set number of deals to meet the qualifiers from the other tables in the next round.
Another tournament format, Elimination Blackjack , drops the lowest-stacked player from the table at pre-determined points in the tournament.
Good strategy for blackjack tournaments can differ from non-tournament strategy because of the added dimension of choosing the amount to be wagered.
As in poker tournaments, players pay the casino an initial entry fee to participate in a tournament, and re-buys are sometimes permitted.
Some casinos, as well as general betting outlets, provide blackjack among a selection of casino-style games at electronic consoles.
Video blackjack game rules are generally more favorable to the house; e. Video and online blackjack games deal each coup from a fresh shoe, rendering card counting much less effective.
Blackjack is a member of a large family of traditional card games played recreationally all around the world. Most of these games have not been adapted for casino play.
Furthermore, the casino game development industry is very active in producing blackjack variants, most of which are ultimately not adopted for widespread use in casinos.
The following are the prominent twenty-one themed comparing card games which have been adapted or invented for use in casinos and have become established in the gambling industry.
Twenty-one or "Siebzehn und Vier" German: An ace can only count as eleven, but two aces count as a blackjack. The game is mostly self-explanatory.
If you make an inferior play, the game will warn you first. I recommend that before you play for real money both online in person that you practice on the game until you very rarely are warned you a making an inferior play.
If doubling or splitting is mathematically the correct play, but you don't have enough chips, the game will give the best advice for what you can afford to do.
Do not change rules mid-hand. If you do, the change will not take effect until the next hand. The deck s is are shuffled after every hand.
If you find any bugs, please contact me. A screenshot would be appreciated if you claim the game is misplaying a hand. I get a lot of incorrect reports that the advice given is incorrect.
This usually can be explained by the user not using the correct basic strategy for the rules selected. I have also had many comments about the advice on a player 16, composed of 3 or more cards, against a As a rule of thumb, the player should stand in that situation.
However, that is a basic strategy exception. The game only knows basic strategy.