Odds On Blackjack

One of the most interesting aspects of blackjack is the
probability math involved. It's more complicated than other
games. In fact, it's easier for computer programs to calculate
blackjack probability by running billions of simulated hands
than it is to calculate the massive number of possible outcomes.

• Odds On Blackjack Switch
• Odds On Blackjack Hands
• Casino Odds On Blackjack

This page takes a look at how blackjack probability works. It
also includes sections on the odds in various blackjack
situations you might encounter.

An Introduction to Probability

1) Blackjack – House Edge from 1%. To many gamblers, Blackjack is the best game to play at casino to win money, especially if you apply a basic winning blackjack strategy. This table game has a house edge, or advantage, of an average 1%, which gives the player a winning advantage of 99%. Jul 24, 2015 This interesting blackjack odds chart is the two card count frequency chart. This chart shows the percentage chance that you will be dealt a hand in each given value range. The most important frequencey to note is the chance of being dealt a natural blackjack (natural 21 value. The odds of being dealt a natural blackjack are merely 4.8%. One of the most attractive features of the game of Blackjack is the low house edge compared to other games on the casino floor. Good players will face a house edge of around 0.5%, and even if you. Blackjack odds are percentage figures which represent your probability of losing or winning a hand. They can also represent the house edge or their profit margins as well. Usually probability odds don't mean much on the short term, but they clearly average out in the long term and this is why the casinos always win over the long term.

Probability is the branch of mathematics that deals with the
likelihood of events. When a meteorologist estimates a 50%
chance of rain on Tuesday, there's more than meteorology at
work. There's also math.

Probability is also the branch of math that governs gambling.
After all, what is gambling besides placing bets on various
events? When you can analyze the payoff of the bet in relation
to the odds of winning, you can determine whether or not a bet
is a long term winner or loser.

The Probability Formula

The basic formula for probability is simple. You divide the
number of ways something can happen by the total possible number
of events.

Here are three examples.

You want to determine the probability of getting heads when
you flip a coin. You only have one way of getting heads, but
there are two possible outcomes—heads or tails. So the
probability of getting heads is 1/2.

You want to determine the probability of rolling a 6 on a
standard die. You have one possible way of rolling a six, but
there are six possible results. Your probability of rolling a
six is 1/6.

You want to determine the probability of drawing the ace of
spades out of a deck of cards. There's only one ace of spades in
a deck of cards, but there are 52 cards total. Your probability
of drawing the ace of spades is 1/52.

A probability is always a number between 0 and 1. An event
with a probability of 0 will never happen. An event with a
probability of 1 will always happen.

Here are three more examples.

You want to know the probability of rolling a seven on a
single die. There is no seven, so there are zero ways for this
to happen out of six possible results. 0/6 = 0.

You want to know the probability of drawing a joker out of a
deck of cards with no joker in it. There are zero jokers and 52
possible cards to draw. 0/52 = 0.

You have a two headed coin. Your probability of getting heads
is 100%. You have two possible outcomes, and both of them are
heads, which is 2/2 = 1.

A fraction is just one way of expressing a probability,
though. You can also express fractions as a decimal or a
percentage. So 1/2 is the same as 0.5 and 50%.

You probably remember how to convert a fraction into a
decimal or a percentage from junior high school math, though.

Expressing a Probability in Odds Format

The more interesting and useful way to express probability is
in odds format. When you're expressing a probability as odds,
you compare the number of ways it can't happen with the number
of ways it can happen.

Here are a couple of examples of this.

You want to express your chances of rolling a six on a six
sided die in odds format. There are five ways to get something
other than a six, and only one way to get a six, so the odds are
5 to 1.

You want to express the odds of drawing an ace of spades out
a deck of cards. 51 of those cards are something else, but one
of those cards is the ace, so the odds are 51 to 1.

Odds become useful when you compare them with payouts on
bets. True odds are when a bet pays off at the same rate as its
probability.

Here's an example of true odds:

You and your buddy are playing a simple gambling game you
made up. He bets a dollar on every roll of a single die, and he
gets to guess a number. If he's right, you pay him $5. If he's
wrong, he pays you $1.

Since the odds of him winning are 5 to 1, and the payoff is
also 5 to 1, you're playing a game with true odds. In the long
run, you'll both break even. In the short run, of course,
anything can happen.

Probability and Expected Value

One of the truisms about probability is that the greater the
number of trials, the closer you'll get to the expected results.

If you changed the equation slightly, you could play this
game at a profit. Suppose you only paid him $4 every time he
won. You'd have him at an advantage, wouldn't you?

• He'd win an average of $4 once every six rolls
• But he'd lose an average of $5 on every six rolls
• This gives him a net loss of $1 for every six rolls.

You can reduce that to how much he expects to lose on every
single roll by dividing $1 by 6. You'll get 16.67 cents.

On the other hand, if you paid him $7 every time he won, he'd
have an advantage over you. He'd still lose more often than he'd
win. But his winnings would be large enough to compensate for
those 5 losses and then some.

The difference between the payout odds on a bet and the true
odds is where every casino in the world makes its money. The
only bet in the casino which offers a true odds payout is the
odds bet in craps, and you have to make a bet at a disadvantage
before you can place that bet.

Here's an actual example of how odds work in a casino. A
roulette wheel has 38 numbers on it. Your odds of picking the
correct number are therefore 37 to 1. A bet on a single number
in roulette only pays off at 35 to 1.

You can also look at the odds of multiple events occurring.
The operative words in these situations are 'and' and 'or'.

• If you want to know the probability of A happening AND
  of B happening, you multiply the probabilities.
• If you want to know the probability of A happening OR of
  B happening, you add the probabilities together.

Here are some examples of how that works.

You want to know the probability that you'll draw an ace of
spades AND then draw the jack of spades. The probability of
drawing the ace of spades is 1/52. The probability of then
drawing the jack of spades is 1/51. (That's not a typo—you
already drew the ace of spades, so you only have 51 cards left
in the deck.)

The probability of drawing those 2 cards in that order is
1/52 X 1/51, or 1/2652.

You want to know the probability that you'll get a blackjack.
That's easily calculated, but it varies based on how many decks
are being used. For this example, we'll use one deck.

To get a blackjack, you need either an ace-ten combination,
or a ten-ace combination. Order doesn't matter, because either
will have the same chance of happening.

Your probability of getting an ace on your first card is
4/52. You have four aces in the deck, and you have 52 total
cards. That reduces down to 1/13.

Your probability of getting a ten on your second card is
16/51. There are 16 cards in the deck with a value of ten; four
each of a jack, queen, king, and ten.

So your probability of being dealt an ace and then a 10 is
1/13 X 16/51, or 16/663.

The probability of being dealt a 10 and then an ace is also
16/663.

You want to know if one or the other is going to happen, so
you add the two probabilities together.

16/663 + 16/663 = 32/663.

That translates to approximately 0.0483, or 4.83%. That's
about 5%, which is about 1 in 20.

You're playing in a single deck blackjack game, and you've
seen 4 hands against the dealer. In all 4 of those hands, no ace
or 10 has appeared. You've seen a total of 24 cards.

What is your probability of getting a blackjack now?

Your probability of getting an ace is now 4/28, or 1/7.
(There are only 28 cards left in the deck.)

Your probability of getting a 10 is now 16/27.

Your probability of getting an ace and then a 10 is 1/7 X
16/27, or 16/189.

Again, you could get a blackjack by getting an ace and a ten
or by getting a ten and then an ace, so you add the two
probabilities together.

16/189 + 16/189 = 32/189

Your chance of getting a blackjack is now 16.9%.

This last example demonstrates why counting cards works. The
deck has a memory of sorts. If you track the ratio of aces and
tens to the low cards in the deck, you can tell when you're more
likely to be dealt a blackjack.

Since that hand pays out at 3 to 2 instead of even money,
you'll raise your bet in these situations.

The House Edge

The house edge is a related concept. It's a calculation of
your expected value in relation to the amount of your bet.

Here's an example.

Expected value is just the average amount of money you'll win
or lose on a bet over a huge number of trials.

Using a simple example from earlier, let's suppose you are a
12 year old entrepreneur, and you open a small casino on the
street corner. You allow your customers to roll a six sided die
and guess which result they'll get. They have to bet a dollar,
and they get a $4 win if they're right with their guess.

Over every six trials, the probability is that you'll win
five bets and lose one bet. You win $5 and lose $4 for a net win
of $1 for every 6 bets.

The expected value of that $1 bet, for the customer, is about
84 cents. The expected value of each of those bets–for you–is
$1.16.

That's how the casino does the math on all its casino games,
and the casino makes sure that the house edge is always in their
favor.

With blackjack, calculating this house edge is harder. After
all, you have to keep up with the expected value for every
situation and then add those together. Luckily, this is easy
enough to do with a computer. We'd hate to have to work it out
with a pencil and paper, though.

What does the house edge for blackjack amount to, then?

It depends on the game and the rules variations in place. It
also depends on the quality of your decisions. If you play
perfectly in every situation—making the move with the highest
possible expected value—then the house edge is usually between
0.5% and 1%.

If you just guess at what the correct play is in every
situation, you can add between 2% and 4% to that number. Even
for the gambler who ignores basic strategy, blackjack is one of
the best games in the casino.

Expected Hourly Loss and/or Win

You can use this information to estimate how much money
you're liable to lose or win per hour in the casino. Of course,
this expected hourly win or loss rate is an average over a long
period of time. Over any small number of sessions, your results
will vary wildly from the expectation.

Here's an example of how that calculation works.

• You are a perfect basic strategy player in a game with a
  0.5% house edge.
• You're playing for $100 per hand, and you're averaging
  50 hands per hour.
• You're putting $5,000 into action each hour ($100 x 50).
• 0.5% of $5,000 is $25.
• You're expected (mathematically) to lose $25 per hour.

Here's another example that assumes you're a skilled card
counter.

• You're able to count cards well enough to get a 1% edge
  over the casino.
• You're playing the same 50 hands per hour at $100 per
  hand.
• Again, you're putting $5,000 into action each hour ($100
  x $50).
• 1% of $5,000 is $50.
• Now, instead of losing $25/hour, you're winning $50 per
  hour.

Effects of Different Rules on the House Edge

The conditions under which you play blackjack affect the
house edge. For example, the more decks in play, the higher the
house edge. If the dealer hits a soft 17 instead of standing,
the house edge goes up. Getting paid 6 to 5 instead of 3 to 2
for a blackjack also increases the house edge.

Luckily, we know the effect each of these changes has on the
house edge. Using this information, we can make educated
decisions about which games to play and which games to avoid.

Here's a table with some of the effects of various rule
conditions. Types of blackjack.

These are just some examples. There are multiple rules
variations you can find, some of which are so dramatic that the
game gets a different name entirely. Examples include Spanish 21
and Double Exposure.

The composition of the deck affects the house edge, too. We
touched on this earlier when discussing how card counting works.
But we can go into more detail here.

Every card that is removed from the deck moves the house edge
up or down on the subsequent hands. This might not make sense
initially, but think about it. If you removed all the aces from
the deck, it would be impossible to get a 3 to 2 payout on a
blackjack. That would increase the house edge significantly,
wouldn't it?

Here's the effect on the house edge when you remove a card of
a certain rank from the deck.

These percentages are based on a single deck. If you're
playing in a game with multiple decks, the effect of the removal
of each card is diluted by the number of decks in play.

Looking at these numbers is telling, especially when you
compare these percentages with the values given to the cards
when counting. The low cards (2-6) have the most dramatic effect
on the house edge. That's why almost all counting systems assign
a value to each of them. The middle cards (7-9) have a much
smaller effect. Then the high cards, aces and tens, also have a
large effect.

The most important cards are the aces and the fives. Each of
those cards is worth over 0.5% to the house edge. That's why the
simplest card counting system, the ace-five count, only tracks
those two ranks. They're that powerful.

You can also look at the probability that a dealer will bust
based on her up card. This provides some insight into how basic
strategy decisions work.

Perceptive readers will notice a big jump in the probability
of a dealer busting between the numbers six and seven. They'll
also notice a similar division on most basic strategy charts.
Players generally stand more often when the dealer has a six or
lower showing. That's because the dealer has a significantly
greater chance of going bust.

Summary and Further Reading

Odds and probability in blackjack is a subject with endless
ramifications. The most important concepts to understand are how
to calculate probability, how to understand expected value, and
how to quantify the house edge. Understanding the underlying
probabilities in the game makes learning basic strategy and card
counting techniques easier.

This is our first blackjack game and trainer and I'm proud to finally add our version 2 with enhanced graphics and the ability to learn how to count cards to my website. 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 advice is based on my own analysis and basic strategy tables for one, two, and four+ decks. 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 10. 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. Also, please note that it is a standard blackjack rule that split aces get one card each. If one of them is a ten, it is not a blackjack, it is just 21 points. That is how blackjack is usually played.

I would like to thank JB for his outstanding work on this game, and Dingo Systems for the cards.

Odds On Blackjack Switch

Online Blackjack Bonuses

We constantly maintain a database of all the casino bonuses from the hundreds of online casinos we have reviewed, and we note which bonuses allow blackjack to count towards the wagering requirements. The below table shows a ranked list of the best money online blackjack bonuses, the ranking also takes into consideration wagering requirements, bonus amount offered, the quality of the site and more.

Blackjack Online FAQ

Q1: What are the rules in online blackjack games?

A: As in land casinos, they vary. Online help files are notoriously badly written and incomplete. The Wizard of Odds, we try hard to keep an accurate listing of rules for every brand of software and live dealers. You may find such rules, for every game, in our Software Review section.

Q2: Generally speaking, are the rules better in land or online casinos?

A: All things considered, I would say they are better online. For one thing, you almost never see a blackjack (ace and 10) pay 6 to 5 only online, while this is becoming the norm in land casinos in the United States.

Q3: What are the typical rules at live dealer casinos online?

A: Live dealer rules are very similar to what you would see in a land casino. The typical rules are:

• Eight decks
• Dealer stands on soft 17
• Dealer does NOT peek for blackjack
• No surrender
• Player may double on any two cards
• Player may double after a split
• No re-splitting

Be careful double or splitting if the dealer has a ten or ace showing. At most live dealer brands, you will lose everything if the dealer gets a blackjack. Under this 'no peek' rule, the only time you should put more money out on the table against a potential dealer blackjack is to split two aces against a dealer 10.

Odds On Blackjack Hands

The house edge under the rules above is 0.61%.

Q4: When are the cards shuffled in online blackjack?

A: In a fully electronic game, they are probably shuffled after every hand. In a live dealer game, they are usually shuffled about half way through the shoe.

Q5: Oh really?! Even with only 50% penetration, what is to prevent me from counting cards against a live dealer?

A: I've asked this question of some people in the business. Nobody would tell me exactly how they protect their game against counters, but they assured me that they do. If I ran a live dealer casino, I would run a test of every player to see how their bet size is correlated to the true count. Then I would carefully examine the play of such players with a strong correlation.

Q6: How do 'probably fair' casinos accomplish so-called in blackjack?

A: It is rather involved, but here is typically how it is done:

1. The casino will generate a random long string of characters, called a Server Seed, hash it, and give the hashed result to the player BEFORE he makes a bet.
2. The player chooses a string of characters himself, called the Client Seed, or accepts a random default provided by the casino.
3. The client and server seed are combined and hashed.
4. The hashed result from step 3 will be parsed somehow, with the hexadecimal characters converted to base 10 and then mapped to specific cards if in a desired range.
5. The game will deal cards according to their order in the hash from step 3. This hash should be long enough that running out of cards would be almost impossible.
6. After the hand, the casino should reveal the Client Seed, which the player may verify hashes to the result provided before the bet. It is then a tedious process above to do all the math to convert the hash to actual cards, but the player may do that if he wishes.

I go into this in greater depth for a particular brand in my page on Blackjack (Encrypted Version).

One of the truisms about probability is that the greater the
number of trials, the closer you'll get to the expected results.

If you changed the equation slightly, you could play this
game at a profit. Suppose you only paid him $4 every time he
won. You'd have him at an advantage, wouldn't you?

• He'd win an average of $4 once every six rolls
• But he'd lose an average of $5 on every six rolls
• This gives him a net loss of $1 for every six rolls.

You can reduce that to how much he expects to lose on every
single roll by dividing $1 by 6. You'll get 16.67 cents.

On the other hand, if you paid him $7 every time he won, he'd
have an advantage over you. He'd still lose more often than he'd
win. But his winnings would be large enough to compensate for
those 5 losses and then some.

The difference between the payout odds on a bet and the true
odds is where every casino in the world makes its money. The
only bet in the casino which offers a true odds payout is the
odds bet in craps, and you have to make a bet at a disadvantage
before you can place that bet.

Here's an actual example of how odds work in a casino. A
roulette wheel has 38 numbers on it. Your odds of picking the
correct number are therefore 37 to 1. A bet on a single number
in roulette only pays off at 35 to 1.

You can also look at the odds of multiple events occurring.
The operative words in these situations are 'and' and 'or'.

• If you want to know the probability of A happening AND
  of B happening, you multiply the probabilities.
• If you want to know the probability of A happening OR of
  B happening, you add the probabilities together.

Here are some examples of how that works.

You want to know the probability that you'll draw an ace of
spades AND then draw the jack of spades. The probability of
drawing the ace of spades is 1/52. The probability of then
drawing the jack of spades is 1/51. (That's not a typo—you
already drew the ace of spades, so you only have 51 cards left
in the deck.)

The probability of drawing those 2 cards in that order is
1/52 X 1/51, or 1/2652.

You want to know the probability that you'll get a blackjack.
That's easily calculated, but it varies based on how many decks
are being used. For this example, we'll use one deck.

To get a blackjack, you need either an ace-ten combination,
or a ten-ace combination. Order doesn't matter, because either
will have the same chance of happening.

Your probability of getting an ace on your first card is
4/52. You have four aces in the deck, and you have 52 total
cards. That reduces down to 1/13.

Your probability of getting a ten on your second card is
16/51. There are 16 cards in the deck with a value of ten; four
each of a jack, queen, king, and ten.

So your probability of being dealt an ace and then a 10 is
1/13 X 16/51, or 16/663.

The probability of being dealt a 10 and then an ace is also
16/663.

You want to know if one or the other is going to happen, so
you add the two probabilities together.

16/663 + 16/663 = 32/663.

That translates to approximately 0.0483, or 4.83%. That's
about 5%, which is about 1 in 20.

You're playing in a single deck blackjack game, and you've
seen 4 hands against the dealer. In all 4 of those hands, no ace
or 10 has appeared. You've seen a total of 24 cards.

What is your probability of getting a blackjack now?

Your probability of getting an ace is now 4/28, or 1/7.
(There are only 28 cards left in the deck.)

Your probability of getting a 10 is now 16/27.

Your probability of getting an ace and then a 10 is 1/7 X
16/27, or 16/189.

Again, you could get a blackjack by getting an ace and a ten
or by getting a ten and then an ace, so you add the two
probabilities together.

16/189 + 16/189 = 32/189

Your chance of getting a blackjack is now 16.9%.

This last example demonstrates why counting cards works. The
deck has a memory of sorts. If you track the ratio of aces and
tens to the low cards in the deck, you can tell when you're more
likely to be dealt a blackjack.

Since that hand pays out at 3 to 2 instead of even money,
you'll raise your bet in these situations.

The House Edge

The house edge is a related concept. It's a calculation of
your expected value in relation to the amount of your bet.

Here's an example.

Expected value is just the average amount of money you'll win
or lose on a bet over a huge number of trials.

Using a simple example from earlier, let's suppose you are a
12 year old entrepreneur, and you open a small casino on the
street corner. You allow your customers to roll a six sided die
and guess which result they'll get. They have to bet a dollar,
and they get a $4 win if they're right with their guess.

Over every six trials, the probability is that you'll win
five bets and lose one bet. You win $5 and lose $4 for a net win
of $1 for every 6 bets.

The expected value of that $1 bet, for the customer, is about
84 cents. The expected value of each of those bets–for you–is
$1.16.

That's how the casino does the math on all its casino games,
and the casino makes sure that the house edge is always in their
favor.

With blackjack, calculating this house edge is harder. After
all, you have to keep up with the expected value for every
situation and then add those together. Luckily, this is easy
enough to do with a computer. We'd hate to have to work it out
with a pencil and paper, though.

What does the house edge for blackjack amount to, then?

It depends on the game and the rules variations in place. It
also depends on the quality of your decisions. If you play
perfectly in every situation—making the move with the highest
possible expected value—then the house edge is usually between
0.5% and 1%.

If you just guess at what the correct play is in every
situation, you can add between 2% and 4% to that number. Even
for the gambler who ignores basic strategy, blackjack is one of
the best games in the casino.

Expected Hourly Loss and/or Win

You can use this information to estimate how much money
you're liable to lose or win per hour in the casino. Of course,
this expected hourly win or loss rate is an average over a long
period of time. Over any small number of sessions, your results
will vary wildly from the expectation.

Here's an example of how that calculation works.

• You are a perfect basic strategy player in a game with a
  0.5% house edge.
• You're playing for $100 per hand, and you're averaging
  50 hands per hour.
• You're putting $5,000 into action each hour ($100 x 50).
• 0.5% of $5,000 is $25.
• You're expected (mathematically) to lose $25 per hour.

Here's another example that assumes you're a skilled card
counter.

• You're able to count cards well enough to get a 1% edge
  over the casino.
• You're playing the same 50 hands per hour at $100 per
  hand.
• Again, you're putting $5,000 into action each hour ($100
  x $50).
• 1% of $5,000 is $50.
• Now, instead of losing $25/hour, you're winning $50 per
  hour.

Effects of Different Rules on the House Edge

The conditions under which you play blackjack affect the
house edge. For example, the more decks in play, the higher the
house edge. If the dealer hits a soft 17 instead of standing,
the house edge goes up. Getting paid 6 to 5 instead of 3 to 2
for a blackjack also increases the house edge.

Luckily, we know the effect each of these changes has on the
house edge. Using this information, we can make educated
decisions about which games to play and which games to avoid.

Here's a table with some of the effects of various rule
conditions. Types of blackjack.

These are just some examples. There are multiple rules
variations you can find, some of which are so dramatic that the
game gets a different name entirely. Examples include Spanish 21
and Double Exposure.

The composition of the deck affects the house edge, too. We
touched on this earlier when discussing how card counting works.
But we can go into more detail here.

Every card that is removed from the deck moves the house edge
up or down on the subsequent hands. This might not make sense
initially, but think about it. If you removed all the aces from
the deck, it would be impossible to get a 3 to 2 payout on a
blackjack. That would increase the house edge significantly,
wouldn't it?

Here's the effect on the house edge when you remove a card of
a certain rank from the deck.

These percentages are based on a single deck. If you're
playing in a game with multiple decks, the effect of the removal
of each card is diluted by the number of decks in play.

Looking at these numbers is telling, especially when you
compare these percentages with the values given to the cards
when counting. The low cards (2-6) have the most dramatic effect
on the house edge. That's why almost all counting systems assign
a value to each of them. The middle cards (7-9) have a much
smaller effect. Then the high cards, aces and tens, also have a
large effect.

The most important cards are the aces and the fives. Each of
those cards is worth over 0.5% to the house edge. That's why the
simplest card counting system, the ace-five count, only tracks
those two ranks. They're that powerful.

You can also look at the probability that a dealer will bust
based on her up card. This provides some insight into how basic
strategy decisions work.

Perceptive readers will notice a big jump in the probability
of a dealer busting between the numbers six and seven. They'll
also notice a similar division on most basic strategy charts.
Players generally stand more often when the dealer has a six or
lower showing. That's because the dealer has a significantly
greater chance of going bust.

Summary and Further Reading

Odds and probability in blackjack is a subject with endless
ramifications. The most important concepts to understand are how
to calculate probability, how to understand expected value, and
how to quantify the house edge. Understanding the underlying
probabilities in the game makes learning basic strategy and card
counting techniques easier.

This is our first blackjack game and trainer and I'm proud to finally add our version 2 with enhanced graphics and the ability to learn how to count cards to my website. 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 advice is based on my own analysis and basic strategy tables for one, two, and four+ decks. 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 10. 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. Also, please note that it is a standard blackjack rule that split aces get one card each. If one of them is a ten, it is not a blackjack, it is just 21 points. That is how blackjack is usually played.

I would like to thank JB for his outstanding work on this game, and Dingo Systems for the cards.

Odds On Blackjack Switch

Online Blackjack Bonuses

We constantly maintain a database of all the casino bonuses from the hundreds of online casinos we have reviewed, and we note which bonuses allow blackjack to count towards the wagering requirements. The below table shows a ranked list of the best money online blackjack bonuses, the ranking also takes into consideration wagering requirements, bonus amount offered, the quality of the site and more.

Blackjack Online FAQ

Q1: What are the rules in online blackjack games?

A: As in land casinos, they vary. Online help files are notoriously badly written and incomplete. The Wizard of Odds, we try hard to keep an accurate listing of rules for every brand of software and live dealers. You may find such rules, for every game, in our Software Review section.

Q2: Generally speaking, are the rules better in land or online casinos?

A: All things considered, I would say they are better online. For one thing, you almost never see a blackjack (ace and 10) pay 6 to 5 only online, while this is becoming the norm in land casinos in the United States.

Q3: What are the typical rules at live dealer casinos online?

A: Live dealer rules are very similar to what you would see in a land casino. The typical rules are:

• Eight decks
• Dealer stands on soft 17
• Dealer does NOT peek for blackjack
• No surrender
• Player may double on any two cards
• Player may double after a split
• No re-splitting

Be careful double or splitting if the dealer has a ten or ace showing. At most live dealer brands, you will lose everything if the dealer gets a blackjack. Under this 'no peek' rule, the only time you should put more money out on the table against a potential dealer blackjack is to split two aces against a dealer 10.

Odds On Blackjack Hands

The house edge under the rules above is 0.61%.

Q4: When are the cards shuffled in online blackjack?

A: In a fully electronic game, they are probably shuffled after every hand. In a live dealer game, they are usually shuffled about half way through the shoe.

Q5: Oh really?! Even with only 50% penetration, what is to prevent me from counting cards against a live dealer?

A: I've asked this question of some people in the business. Nobody would tell me exactly how they protect their game against counters, but they assured me that they do. If I ran a live dealer casino, I would run a test of every player to see how their bet size is correlated to the true count. Then I would carefully examine the play of such players with a strong correlation.

Q6: How do 'probably fair' casinos accomplish so-called in blackjack?

A: It is rather involved, but here is typically how it is done:

1. The casino will generate a random long string of characters, called a Server Seed, hash it, and give the hashed result to the player BEFORE he makes a bet.
2. The player chooses a string of characters himself, called the Client Seed, or accepts a random default provided by the casino.
3. The client and server seed are combined and hashed.
4. The hashed result from step 3 will be parsed somehow, with the hexadecimal characters converted to base 10 and then mapped to specific cards if in a desired range.
5. The game will deal cards according to their order in the hash from step 3. This hash should be long enough that running out of cards would be almost impossible.
6. After the hand, the casino should reveal the Client Seed, which the player may verify hashes to the result provided before the bet. It is then a tedious process above to do all the math to convert the hash to actual cards, but the player may do that if he wishes.

I go into this in greater depth for a particular brand in my page on Blackjack (Encrypted Version).

Q7: I don't want to bother jumping through all those hoops to verify fairness in an encrypted game. Do you think that just the ability to verify fairness is enough to keep the casinos honest?

Casino Odds On Blackjack

A: No. Encrypted or not, a casino could cheat the player in any game, except sports betting, any time they wished. In the case of an encrypted casino, the operator could choose a Server Seed that causes the player to lose after the bet is made. If the player catches them in a hash mismatch, which I think very few players bother to check, the casino can simply ignore the accusation or deny it without comment. This is exactly what happened to me at Wixiplay.

Q8: Your story aside, how common is cheating at blackjack, or any game, online?

A: In my opinion, it is quite rare.

Q9: How can I improve my odds of not being cheated?

A: There are hundreds, perhaps thousands, of Internet casinos out there. In the absence of any serious government regulation, the industry has done a pretty good job of regulating itself. Between legitimate watchdog affiliate sites and some common sense, here are some ways to choose a reputable brand to trust with your hard-earned dollar:

• Read the fine print. Most casinos have a good looking main page, but dig around the more obscure pages like terms & conditions. If you see a lot of spelling and grammatical mistakes, that should set off a red flag.
• Ping customer support. If you can't think of your own question, ask anything, for example, 'Do you accept players from Kyrgyzstan?' See how long it takes for them to reply and measure their professionalism and courtesy of their reply.
• Check reputable affiliate sites. Many affiliate sites promote whoever pays the most, but the good ones are picky about who they promote and will intervene in the unlikely event of a player dispute. We would like to think of ourselves as one of the good ones. A good way to avoid the worst of casinos is to check the blacklists of reputable affiliates.
• Smart small. Players should always bet in moderation anywhere, but especially when opening a new account online with an unfamiliar brand. Dink around with a small deposit and small bets until you have built up some trust.

Q10: Any other words of advice before playing blackjack online?

A: Whether playing online or in a land casino, use the appropriate basic strategy for the rules offered. The Wizard of Odds blackjack strategy calculator will give the correct basic strategy for almost any set of rules.
A much greater problem than outright cheating is online casinos faulting players on a technicality in the rules and seizing whatever funds they deem appropriate. This is a particularly a problem with bonuses. The terms and conditions for bonuses can be pages long and very restrictive in terms of allowed games, bet sizes, and types of bets. If the player loses, nobody ever checks, but after a win and withdrawal request, suddenly the play may be subject to careful review for compliance. Never assume that because you were invited to play a bonus via Email that you're eligible for it. Casinos typically blast everybody in their list. An easy rule to overlook is when a bonus is eligible for 'new money' only. Don't expect the casino to enforce this rule when entering a couple code, but do expect it when you actually make a withdrawal and they look for any reason to deny it.
While bonuses can make your money last much longer and increase your chances of winning, they are a minefield in terms of compliance. Read the rules carefully. If in doubt the way you play is compliant, then don't ask for the bonus in the first place.