Blackjack: This Article Is About The Gambling Game. For Other Uses, See
Blackjack: This Article Is About The Gambling Game. For Other Uses, See
Contents
[hide]
1 History of blackjack
2 How to play blackjack
o 2.1 Player decisions
4 Blackjack strategy
o 4.1 Basic strategy
o 4.2 Card counting
o 4.3 Composition-dependent strategy
o 4.4 Shuffle tracking and other advantage-play
techniques
5 Variants
6 Blackjack Hall of Fame
7 Notes
8 Sources
9 External links
o 9.1 Blackjack calculators
[edit]History of blackjack
Blackjack`s precursor was "twenty-one," a game of unknown origin. The first written reference is to be
found in a book of Miguel de Cervantes, the author of Don Quixote, and a gambler himself. The main
characters of his tale "Rinconete y Cortadillo", from "Novelas Ejemplares", are a couple of cheaters
working in Seville. They are proficient at cheating at "veintiuna" (Spanish for twenty-one), and stated that
the object of the game is to reach 21 points without busting, and that the Ace values 1 or 11. The game is
played with the Spanish deck, that is without tens, which makes the game similar to the current Spanish
21. This short story was written between 1601 and 1602, so the game was played inCastilia since the
beginning of the 17th Century or even earlier. Later references of this game are to be found in France and
Spain.[2]
When 21 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. In the modern game, a "natural" or "blackjack" is simply an ace plus a ten-
value card.
Example of a Blackjack game. The top half of the picture shows the beginning of the round, with bets placed and an initial two
cards for each player. The bottom half shows the end of the round, with the associated losses or payoffs.
Cards are dealt in three ways, either from one or two hand-held decks, from a box containing four to eight
decks called a "shoe," or from a shuffling machine. When dealt by hand, the player's two initial cards are
face-down, while the dealer has one face-up card called the "upcard" and one face-down card called the
"hole card." (In European blackjack, the hole card is not actually dealt until the players all play their
hands.) When dealt from a shoe, all player cards are normally dealt face-up, with minor exceptions. It
shouldn't matter to the player whether his cards are dealt face-down or face-up since the dealer must play
according to predetermined rules. If the dealer has less than 17, he must hit. If the dealer has 17 or more,
he must stand (take no more cards), unless it is a "soft 17" (a hand that includes an ace valued as "11," for
example a hand consisting of Ace+6, or Ace+2+4). With a soft 17, the dealer follows the casino rules
printed on the blackjack table, either to "hit soft 17" or to "stand on all 17's."
The highest possible hand is a "blackjack" or "natural," meaning an initial two-card total of 21 (an ace and
a ten-value card). A player blackjack is an automatic winner unless the dealer also has blackjack, in which
case the hand is a "push" (a tie). When the dealer upcard is an ace, the player is allowed to make a side
bet called "insurance," supposedly to guard against the risk that the dealer has a blackjack (i.e., a ten-
value card as his hole card). The insurance bet pays 2-to-1 if the dealer has a blackjack. Whenever the
dealer has a blackjack, he wins against all player hands except those that also have a blackjack (which are
a "push").
The minimum and maximum bets are posted on the table. The payoff on most bets is 1:1, meaning that
the player wins the same amount as he bets. The payoff for a player blackjack is 3:2, meaning that the
casino pays $3 for each $2 originally bet. (There are many single-deck games which pay only 6:5 for a
blackjack.)
[edit]Player decisions
After receiving his initial two cards, the player has four standard options: he can "Hit," "Stand," "Double
Down," or "Split a pair." Each option requires the use of a hand signal. At some casinos or tables, the
player may have a fifth option called "Surrender."
signal: (handheld) scrape cards against table; (face up) touch finger to table or wave hand toward
himself
signal: (handheld) slide cards under bet; (face up) wave hand horizontally
Double down: On his first two cards, the player may "double down," i.e., "double" his bet and
receive only one card. To do this he moves a second bet equal to the first into the betting box next to
his original bet. (If desired, the player is usually allowed to "double down for less," although this is
generally not a good idea as the player should only double in favorable situations but should then
increase the bet as much as possible.)
signal: place additional chips next to (not on top of) original bet
Split a pair: If his first two cards are a "pair," meaning two cards of the same value, the player
can "split the pair." To do this, he moves a second bet equal to the first into the betting box next to his
original bet. The dealer splits the cards to create two hands, placing one bet with each hand. The
player then plays two separate hands.
signal: place additional chips next to (not on top of) original bet.
Surrender: Some casinos offer a fifth option called "Surrender." After the dealer has checked for
blackjack, the player may "surrender" by giving up half his bet and not playing out the hand.
The reason for requiring hand signals is to assist the "eye in the sky," a person or video camera located
above the table but concealed behind one-way glass. It is used in order to protect the casino against
dealers or players who cheat. (It may also be used to protect the casino againstcard-counters, even
though card-counting is not illegal.)
The player can take as many hits as he wants as long as the total is not above hard-20. However, if he
busts, he loses that hand. After all the players have finished making their decisions, the dealer then
reveals his hole card and plays out his or her hand according to predetermined rules.
The casino has a "house advantage" at blackjack just as it does at any other casino game. If a particular
casino game has a house advantage of 5%, it means that - over the long run - the casino will win about
5% of any initial bet. As long as the blackjack player uses the best possible strategy (a strategy which is
known as "Basic Strategy"), the house advantage in blackjack is usually less than 1%. This is very
favorable to the player compared to other casino games. Of course, many blackjack players do not know
Basic Strategy or do not follow it, so the true house advantage in those cases is much higher.
[edit]Dealer hits soft 17?
Each casino has a rule about whether or not the dealer hits soft 17, a rule which is printed on the table
itself. In the "S17" game, the dealer stands on all 17s. In the "H17" game, the dealer hits on soft 17s. Of
course, the dealer always stands on hard 17s. In either case, the dealer has no choice; he
either must or must not hit. The "Hit soft 17" game is less favorable to the player with about a 0.2%
higher house advantage.
[edit]Number of decks
The number of decks used has a major effect on the player's chance of winning, because it affects the
house advantage. (See comparative statistics below.) All things being equal, fewer decks are always more
favorable for the basic strategy player. One cause of this is that player blackjack is slightly more likely in
single deck blackjack (because blackjack requires two different cards, by removing a card of one type
(e.g., a Ten), getting one of a different type (e.g. an Ace) is more likely - and the effect is much bigger in
a single deck game than in a multi-deck game), and if the player does have blackjack, the dealer is
significantly less likely to have blackjack as well (which is a push), meaning that the player will get paid
at 3:2 more often in the single deck game.
In reality, multi-deck games almost always have otherwise better rules than single-deck games. However,
card counting is much more effective for single deck games. For illustrative purposes, the statistics below
all use the same rules—double after split, no resplits, one card to split Aces, no surrender, double on any
two cards, original bets only lost on dealer Blackjack, dealer hits soft 17. The single deck game is much
better than double deck, which is significantly better than four decks, while from six decks and up there is
very little difference.
[edit]Surrender
Some casinos offer a favorable option called "surrender," which allows the player to give up half his bet
and not play out the hand. This option is sometimes referred to as "late" surrender because it
occurs after the dealer has checked his or her hole card for a blackjack. (When casinos first opened in
Atlantic City, the surrender option was available before the dealer checked for blackjack - a rule highly
advantageous to the player - but this "early surrender" option soon disappeared.) Early Surrender
variations still exist in several countries.
The player will only surrender on the very worst hands, because having even a 25% chance of winning
will result in a better average return than giving up half of his bet. See strategy table below for details.
With early surrender, a player will surrender very often against a dealer Ace - even including hard 17.
[edit]Resplit to nn
If the player splits a pair other than aces and a third card of that value appears, the player can usually
resplit by putting up another bet equal to the original bet. Then there will be three bets on the table and
three separate hands. Some casinos allow unlimited resplitting of cards other than aces, while others may
limit it to a certain number of hands, such as four hands (for example, "resplit to 4").
[edit]Hit/resplit split aces
After splitting aces, the usual rule is that only one card will be dealt - the player cannot split, double or
even hit. Rule variants include allowing resplitting aces and allowing the player to hit split aces. Allowing
the player to hit Aces reduces the casino edge by about 0.13%, allowing resplitting Aces reduces the edge
by about 0.03%.
In some places, if the dealer is later found to have blackjack, the player loses only his original bet but
not any additional bets (doubles or splits). This has the same advantage as the usual game, and as such
does not change basic strategy.
[edit]Altered payout for blackjack
In some places, a blackjack pays only 6:5 or even 1:1 instead of the usual 3:2. This is the most
unfavorable variation, increasing the house edge significantly more than any other player restriction.
Since blackjack occurs in approximately 4.8% of hands, the 1:1 game increases the house edge by 2.3%,
while the 6:5 game adds 1.4% to the house edge. The 1:1 payout for video blackjack is a key reason why
it has never approached the table version in terms of popularity. The 6:5 rule is most commonly employed
on table blackjack at single deck games - which are otherwise the most attractive game for a basic
strategy player.
If the dealer's upcard is an ace, the player is offered the option of taking Insurance before the dealer
checks his or her 'hole card'.
Insurance is a side bet of up to half the original bet placed on a special portion of the table usually marked
"Insurance Pays 2 to 1". This side bet is offered only when the dealer's exposed card is an ace. The idea is
that the dealer's second card has a fairly high probablility (nearly one-third) to be ten-valued, giving the
dealer a blackjack and a certain loss for the player. It is attractive (although not necessarily wise) for the
player to insure against this possibility by making an "insurance" bet, which pays 2-to-1 if the dealer has a
blackjack, in which case the "insurance proceeds" will make up for the concomitant loss on the original
bet. The insurance bet is lost if the dealer does not have blackjack, although the player can still win or
lose on the original bet.
Insurance is a poor bet for the player unless he is counting cards, because in an infinite deck 4/13 of the
cards are "tens" (10, J, Q, or K) (and 9/13 therefore are not), so the theoretical return for an infinite deck
game is 4/13 * 2 * bet - 9/13 * bet = -1 /13 * bet, or -7.69%. In practice, the average house edge will be
lower than this, because by eliminating even one non-ten card from the shoe (the dealer's Ace), the
proportion of the remaining cards that are tens is higher. Even so, the bet is generally to be avoided, as the
the house's average edge is still more than 7%.
A player who is counting cards can keep count of the remaining tens in the shoe, and use it to make
insurance bets only when he has an edge (i.e. when more than one third of the remaining cards are tens).
In addition, in a multi-hand single deck game, it is possible for insurance to be a good bet simply by
observing the other cards on the table - if the dealer has an Ace, then there are 51 cards left in the deck, of
which 16 are tens. However, if there are as few as 2 players playing, and none of their two initial cards
are tens, then that means that 16 out of 47 remaining cards, are ten - better than 1 in 3, and so the
insurance bet is a good one.[1]
When the player has blackjack and the dealer has an ace, the insurance bet may be offered as "even
money", meaning that the player'sblackjack is paid immediately at 1:1 before checking the dealer's hand.
'Even money' is just a way of expressing the actual payout on the insurance bet, given that the player has
blackjack, it is not a different bet, and taking even money is generally even worse than average, because
one of the player's two cards is tens, so the proportion of tens remaining in the deck is lower.
In casinos where a hole card is dealt, a dealer who is showing a card with a value of Ace or 10 may slide
the corner of his hole card over a small mirror or electronic sensor on the tabletop in order to check
whether he has a blackjack. This practice minimizes the risk of inadvertently revealing the hole card,
which may give the sharp-eyed player a considerable advantage.
[edit]Side bets
Some casinos offer a side bet with their blackjack games. Examples include side bets based on getting
three 7s, a three card poker-style bet, a pair, and many others.[2] For the sidebet, the player will typically
put up an additional wager alongside his main bet. Typically the player can win or lose the sidebet,
regardless of the main game result. As there is little or no strategy involved, the house edge for side bets
is usually much higher than the main game (which requires accurate play).
[edit]Blackjack strategy
[edit]Basic strategy
Because blackjack has an element of player choice, players can reduce casino advantage by playing
optimally. The complete set of optimal plays is known as basic strategy. There are slight variations
depending on the house rules and number of decks.
17-20 S S S S S S S S S S
16 S S S S S H H SU SU SU
15 S S S S S H H H SU H
13-14 S S S S S H H H H H
12 H H S S S H H H H H
11 Dh Dh Dh Dh Dh Dh Dh Dh Dh H
10 Dh Dh Dh Dh Dh Dh Dh Dh H H
9 H Dh Dh Dh Dh H H H H H
5-8 H H H H H H H H H H
Soft totals
2 3 4 5 6 7 8 9 10 A
A,8 A,9 S S S S S S S S S S
A,7 S Ds Ds Ds Ds S S H H H
A,6 H Dh Dh Dh Dh H H H H H
A,4 A,5 H H Dh Dh Dh H H H H H
A,2 A,3 H H H Dh Dh H H H H H
Pairs
2 3 4 5 6 7 8 9 10 A
A,A SP SP SP SP SP SP SP SP SP SP
10,10 S S S S S S S S S S
9,9 SP SP SP SP SP S SP SP S S
8,8 SP SP SP SP SP SP SP SP SP SP
7,7 SP SP SP SP SP SP H H H H
6,6 SP SP SP SP SP H H H H H
5,5 Dh Dh Dh Dh Dh Dh Dh Dh H H
4,4 H H H SP SP H H H H H
2,2 3,3 SP SP SP SP SP SP H H H H
The above is a basic strategy table for 3 or more decks, dealer stands on soft 17, double on any 2 cards,
double after split allowed, dealer peeks for blackjack, and blackjack pays 3:2. Key:
S = Stand
H = Hit
Dh = Double (if not allowed, then hit)
Ds = Double (if not allowed, then stand)
SP = Split
SU = Surrender (if not allowed, then hit)
Most Las Vegas strip casinos hit on soft 17. This rule change requires a
slightly modified basic strategy table—double on 11 vs A, double on A/7
vs 2, and double on A/8 vs 6. Most casinos outside of Vegas still stand
on soft 17.
[edit]Card counting
Main article: 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.
The player can make larger bets when he 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.
[edit]Shuffle
tracking and other advantage-
play techniques
Techniques other than card-counting can swing the advantage
of casino blackjack towards 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. Thorp. .[9] One
technique, mainly applicable in multi-deck games, involves
tracking groups of cards (aka slugs, clumps, packs) during the
play of the shoe, following them through the shuffle and then
playing and betting accordingly when those cards come into
play from the new shoe. This technique, which is admittedly
much more difficult than straight card-counting and requires
excellent eyesight and powers of visual estimation, has the
additional benefit of fooling the casino people who are
monitoring the player's actions and the count, since the shuffle
tracker could be, at times, betting and/or playing opposite to
how a straightforward card-counter would.[10]
[edit]Variants
[edit]Notes
19 2006.
BlackjackinColor
[edit]Blackjack calculators
Many side count techniques exist including special-purpose counts used when attacking games with
nonstandard profitable-play options such as an over/under side bet. [3]
The disadvantage of higher-level counts is that keeping track of more information can detract from the
ability to play quickly and accurately. A card-counter might earn more money by playing a simple count
quickly—more hands per hour played—than by playing a complex count slowly.
The following table illustrates various ranking systems for card counting. [4]
Card Strategy 2 3 4 5 6 7 8 9 10 J Q K A
Wizard
0 0 0 +1 0 0 0 0 0 0 0 0 −1
Ace/Five
KO +1 +1 +1 +1 +1 +1 0 0 −1 −1 −1 −1 −1
Hi-Lo +1 +1 +1 +1 +1 0 0 0 −1 −1 −1 −1 −1
Hi-Opt I 0 +1 +1 +1 +1 0 0 0 −1 −1 −1 −1 0
Hi-Opt II +1 +1 +2 +2 +1 +1 0 0 −2 −2 −2 −2 0
Zen Count +1 +1 +2 +2 +2 +1 0 0 −2 −2 −2 −2 −1
Omega II +1 +1 +2 +2 +2 +1 0 −1 −2 −2 −2 −2 0