Odds of winning at blackjack in different scenarios

Blackjack! Here are the chances of winning blackjack in different scenarios – Photo by Drew Rae from Pexels

Blackjack has been played for centuries but the traditional rules of the game remain the same.

Several versions of the game have since been made but the main version remains the most popular in physical casinos and online just the same.

Although the rules sound simple, getting closer to the dealer to 21 without going over, the game ultimately comes down to a combination of chance, probability and whether you decide to hit or stand in certain situations.

First and foremost, be sure to understand the rules for playing blackjack before you play the game for real money. Whether you can pick them up by reading them or playing a free version of the game whilst you read them.

It is then recommended that your decision to hit or stand is based on your probability of winning from each scenario.

Your starting hand

Your starting hand should have a huge influence over your decision – Photo by Clifford Photos from Pexels

The best starting hand you can possibly get is a Blackjack. That’s being dealt an ace with a picture card or value of 10 in either order. You cannot lose with that hand and in most scenarios you will win without having to make a move.

Playing with a single deck, the probability of getting an ace with your first card is 4/52, or 1/13. This is because there are four aces in a standard deck of 52 cards.

The probability of getting a 10 with your second card then becomes 16/51. There are 16 cards in the deck with a value of 10 – four each of the King, Queen Jack and 10 itself.

The maths sum to work out your probability of being dealt these is 1/13 x 16/51, or 16/663.

Likewise, the probability of you being dealt a 10 then an ace is also 16/663.

As we want to know if either event is going to happen, we need to add the two probabilities together, which gives us 16/663 + 16/663 = 32/663.

This means there is a 0.0483, or 4.83% chance of getting a Blackjack with our first two cards when playing one-on-one versus the dealer with a single deck of cards. That’s just short of 5%, so about a 1 in 20 chance.

The house edge

The house edge – Photo by Javon Swaby from Pexels

All casino games have a house edge in their favour. This is the calculation of your expected value in relation to your stake.

An example is that you have placed a £20 wager. Your expected value is £19, meaning the house edge is 5%.

This is the amount of money a player will win or lose on a bet on average over a lengthy period of hands.

In the game of blackjack there can be different rules in place meaning that the house edge varies from version to version. It also depends on your decisions too. But if you were to play perfectly in every situation, making the decision with the highest possible expected value, then the house edge is usually only between 0.5% and 1%.

On the other hand, if you just guess at what the correct play is in every scenario, you will be adding between 2% and 4% to the house edge value.

Other conditions that change the house edge are if the dealer hits a soft 17 instead of standing, the value goes up. Or if you get paid 6 to 5 instead of 3 to 2 for a blackjack, this also increases the house edge.

Your strategy depends on the scenario

Let’s go through the most universal basic strategy that can be used in all versions of blackjack.

The chart below has the dealer’s up card running across the top and your cards are listed down the left column. If you’re playing blackjack online, then you can have this chart alongside you to play with. If playing in a physical casino then you will need to memorise it.

The key:

Hit = Hit
Stand = Stand
DblH = Double
DblS = Double if permitted, otherwise stand
Split = Split
SplitD = Split if double after split is permitted, otherwise hit
SUR = Surrender if permitted, otherwise hit

The chart above should be used when making your decision. Having the correct plays written down is valuable to many players.

If the chart above is too complex to read then below is the text version, describing your hand and the instruction you should take:

Ace-Ace = Split

Ace-two or soft 13 = Hit with a soft 13 and double if allowed against a dealer five or six

Ace-three or soft 14 = Hit and double against a five or six

Ace-four or soft 15 = Hit with a soft 15 and double against a dealer four, five, or six

Ace-five or soft 16 = Hit and double against a four, five, and six

Ace-six or soft 17 = Double against a three, four, five, and six

Ace-seven or soft 18 = Stand against a dealer two, seven, and eight, hit against a nine, 10, or ace, and double against three, four, five, or six

Ace-eight or soft 19 = Stand

Ace-nine or soft 20 = Stand

Ace-10 = Blackjack! Stand

Pairs

Whenever you have a pair as your first two cards the below will help you decide if you need to split.

2s = Split against a dealer four, five, six, and seven, hit against a dealer eight, nine, 10, and ace, and against a dealer two or three split if you can double after split and hit if double after split isn’t allowed.

3s = Play the same as a pair of twos.

4s = When double after split is allowed split against a dealer five and six, otherwise hit. Hit against all other dealer cards.

5s = Never split fives. Hit against a dealer 10 or ace and double against all other dealer cards.

6s = Hit against a dealer seven, eight, nine, 10, and ace. Split against a dealer three, four, five, and six. Split against a dealer two if double after split is allowed, otherwise hit.

7s = Split against a dealer two, three, four, five, six, and seven. Hit against a dealer eight, nine, 10, and Ace.

8s = Split

9s = Split against a dealer two, three, four, five, six, eight, and nine. Stand against a dealer seven, 10, and Ace.

10s = Stand

Aces = Split

Hard totals

Hard four = The only hard four is a pair of twos. This is covered in the 2s line above.

Hard five = Hit

Hard six = Hit

Hard seven = Hit

Hard eight = Hit

Hard nine = Double against a dealer three, four, five, or six. Hit against all other dealer cards

Hard 10 = Double against a dealer two, three, four, five, six, seven, eight, and nine. Hit against a dealer 10 and Ace.

Hard 11 = Double against any dealer card except an Ace. Hit against a dealer Ace.

Hard 12 = Stand against a dealer four, five, and six. Hit against all other dealer cards

Hard 13 = Stand against a dealer two, three, four, five, and six. Hit against a dealer seven, eight, nine, 10, and Ace

Hard 14 = Stand against a dealer two, three, four, five, or six and hit against seven or higher

Hard 15 = Stand against a dealer two, three, four, five, and six and hit against a dealer seven, eight, nine, 10, and Ace

Hard 16 = Stand against a dealer total of two, three, four, five, and six. Hit against all other dealer totals

Hard 17 = Stand

Hard 18 = Stand

Hard 19 = Stand

Hard 20 = Stand

Hard 21 = Blackjack! Stand