Double Down Blackjack

Double Down Blackjack -The Complete Guide to Blackjack Double Down Theory and Strategy

If you’re eager to learn about playing blackjack, you have to understand the double down rule. Unfortunately, this isn’t some magical way to beat the dealer. However, it is an added extra that can help increase your returns when the cards are on your side.

In this guide, we’re going to answer the all-important question: what does doubling down mean in blackjack? Once we’ve covered the basics, we’ll tell the best doubling down blackjack strategy so you can swing things in your favour when lady luck is on your side. 

If you’ve ever played blackjack online or live, you’ll know there are two basic moves: hit and stand. However, in certain instances, you’ll have the option to double down. This is an extra move that costs money but allows you to increase your potential win rate in advantageous situations. Like all “extras”, the double down in blackjack is optional. However, once you understand what it is and when to double down in blackjack, it can be a powerful tool to have in your arsenal.

What is Doubling Down in Blackjack?

Doubling down in blackjack is the process of adding another bet to the table in order to receive a single card. Now, that’s the basic answer. However, the acting of doubling down actually means more than making an extra bet. To keep things simple, let’s call the blackjack double down move an advantage play.

Whenever you double down in blackjack, it’s because the game dynamics are weighed in your favour. We’ll cover what this means in the following subsections. However, in answering the question “what does doubling down mean in blackjack?”, we have to acknowledge that it’s more than a betting option. Therefore, to give a complete answer, we can make the following statement:

Doubling down in blackjack require the player to make an extra bet and receive one additional card. This move is commonly made when the player is in an advantageous position i.e. they have a strong chance of making a total of close to or 21 exactly, and the dealer’s up-card is weak.

When the Blackjack Double Down is an Advantage for the Player

If we accept that the double down blackjack move is an advantage play, we have to ascertain why this is the case. Firstly, we need some rules for when to double down in blackjack. As a basic guide, you need the following to be true:

• You have a two-card starting total that’s likely to make a score of 20 or 21 e.g. your starting total is 10 or 11.
• The dealer has a weak up-card e.g. a 3, 4, 5 or 6.

If the following two conditions are present, you’re in a strong position as the player. Whenever you’re in this type of position, it’s important to press home your advantage. In this case, that means adding more money to the table.

By paying to double down in blackjack (the cost is equal to your opening bet), you’re giving yourself the chance to maximise your returns when you’re strong and the dealer is weak. Over time, this should improve your overall win rate which, of course, is what you want when you’re playing for money.

When the Blackjack Double Down is a Disadvantage

Like all advantage plays in the casino world, there are some downsides to doubling down. Obviously, you are risking more money because you have to match your opening bet. However, the major disadvantage of blackjack double down rules is that you only receive one card. Therefore, you may finish with a poor total.

For example, if your starting total was 11, you could hit and receive a 3. This takes your total to 14 which, in most cases, isn’t worth standing on. At this point, you could hit again and try to improve your score. In contrast, if you doubled down on 11 and received a 3, that’s your lot. In other words, you’re stuck with 14. That’s the risk you take when you make a blackjack double play.

Casino Rules for Doubling Down

Once you know how to double down in blackjack and when the best times to do it are, you need to consider the rules in play. Every casino, moreover, type of blackjack, may have slightly different blackjack double down rules. For example, in some games, you may be able double on any starting total. Others may restrict you to doubling down on totals of 10 and 11.

Other than subtle differences in when to double down in blackjack, the cost will always be the size of your opening bet. So, if you wagered 1 coin, it could cost 1 coin to double. Finally, you will always receive one card only when you double down in blackjack.

What is the Value the Dealer Must Hit and Stand on in Blackjack?

The dealer must always hit a score of 17+ in blackjack. To put it another way, the dealer can’t stand on any total that’s 16 or lower. This rule guides our decision to double down or not. Indeed, we’ve already said that you need the dealer to be “weak” in order to double at the best time. We can say the dealer is weak when they’re showing a 3, 4, 5, or 6 because they have to hit to 17+.

Why is this the case? Because there are more cards with a value of 10 in play than any other, we always have to assume the next card will be worth 10. Therefore, if the dealer is showing a 5, we know their best score can be 16 (i.e. if their hidden card is an ace). With that being true, they will have to draw a third card. Whenever you draw in blackjack, there’s some risk involved. Thus, we can say the dealer is weak with a 5.

Blackjack Bust Percentage

Of course, we can’t always assume the dealer will go bust. In fact, according to the numbers, the dealer’s blackjack bust percentage on any given hand is 28.36%. However, the closer we move to up-cards worth 4, 5, or 6, the greater their chance of busting becomes. For example, with an ace, the bust chance is 11.65%. However, with a 6, the chance is 42.08%. Therefore, when it comes to defining rules for when to double down in blackjack, you want to ensure the dealer’s chance of busting is high.

•          Dealer's Face UP Card: 2
•          Dealer Average Percentage: 35%
•          Player Average Percentage: 10%

•          Dealer's Face UP Card: 3
•          Dealer Average Percentage: 37%
•          Player Average Percentage: 13%

•          Dealer's Face UP Card: 4
•          Dealer Average Percentage: 40%
•          Player Average Percentage: 18%

•          Dealer's Face UP Card: 5
•          Dealer Average Percentage: 42%
•          Player Average Percentage: 23%

•          Dealer's Face UP Card: 6
•          Dealer Average Percentage: 42%
•          Player Average Percentage: 24%

•          Dealer's Face UP Card: 7
•          Dealer Average Percentage: 26%
•          Player Average Percentage: 14%
•           Dealer's Face UP Card: 8
•          Dealer Average Percentage: 24%
•          Player Average Percentage: 5%  
•          Dealer's Face UP Card: 9
•          Dealer Average Percentage: 23%
•          Player Average Percentage: -4%

•          Dealer's Face UP Card: 10
•          Dealer Average Percentage: 23%
•          Player Average Percentage: -17%

•          Dealer's Face UP Card: J, Q, K
•          Dealer Average Percentage: 23%
•          Player Average Percentage: -17%

•          Dealer's Face UP Card: Ace
•          Dealer Average Percentage: 17%
•          Player Average Percentage: -16%

Now we're starting to get into the nitty-gritty of what is double down in blackjack, by defining our own blackjack double down rules, we can build up an idea of when and how you can best implement this advantage play in practice.

Doubling Down on 10 or 11

In most cases, it’s a good idea to double down on a starting total of 10 or 11. However, you shouldn’t use this move if the dealer is strong. According to the double down blackjack chart, you shouldn’t make this move under the following conditions:  

If your starting total is 10, you shouldn’t double down if the dealer is showing a 10 or an ace.

If your starting total is 11, you shouldn’t double down if the dealer is showing an ace.

Doubling Down on 9

If your starting total is 9, you’re in a strong position to make the blackjack double down play. However, you need to be more cautious compared to if you hold 10 or 11. As a general guide, you should double down with a starting total of 9 if the dealer is showing a 3, 4, 5, or 6.

Doubling Down on 8

Despite what you might think, a starting total of 8 isn’t ideal for doubling down on. Even though it has the potential to make a strong hand, it’s not enough to make doubling a winning long-term play.

Now, if you’re playing an aggressive strategy, you could double on 8 if the dealer is weak. However, this is a risky move. Looking at a when to double down in blackjack chart, the maths state that you shouldn’t make this move, regardless of what the dealer is showing.

Doubling Down on Hard Counts

In blackjack, a hard count is a total that doesn’t contain an ace. Because aces are worth 1 or 11, hands with an ace in are described as soft i.e. there are two possible values. In contrast, hard totals are fixed.

With that being the case, there’s slightly more risk when it comes to doubling on hard totals. Because of that, you need to have separate rules for these two instances. For reference, you should double on the following had totals (excluding pairs):

• 11 = double when the dealer is showing any card except an ace.
• 10 = double when the dealer is showing any card except a 10 or ace.
• 9 = double when the dealer is showing a 3, 4, 5, or 6.

Doubling Down on Soft Counts

If your hand is soft, you can double under the following conditions if the table rules allow:

• A-8/A-9 = Don’t double.
• A-7 = double when the dealer is showing a 3, 4, 5, or 6.
• A-6 = double when the dealer is showing a 3, 4, 5, or 6.
• A-4/A-5 = double when the dealer is showing a 4, 5, or 6.
• A-2/A-3 = double when the dealer is showing a 5, or 6.

Doubling Down After Split in Blackjack

Under some blackjack double down rules, you can double down after splitting a pair. If this move is possible, you should simply treat your split hand as two new hands and double according to the rules we’ve outlined so far.

In some games, there may be subtle twists on the blackjack double down rule. They are:

Doubling Down on Any Number of Cards/Doubling Down on Three Cards

In general, you can only double down with two cards. However, there may be individual table rules that allow you to double down on 3 or any number of cards. If you can make these moves, you should base your move on the strength of your hand, the chance of busting, and the dealer’s up-card.

What is the Redouble Rule in Blackjack?

Another special condition, the redouble rule in blackjack is the rule which allows you to double after a double. If you double for a second time, it costs you the amount of your initial bet (not the total wagered to that point). This is a tricky move in terms of strategy. However, you can use this as an aggressive play when the dealer is weak and you’re at little risk of going bust.

Discard Double

Although it’s rare, there are times you can give up your hand after doubling down in blackjack. If this option is available, you can pay to double and then get back some of your stake if you decide not to proceed and see what the dealer’s total is.

Hit After a Double Down

In some games, you can hit after doubling down. In this sense, you’re simply playing the hand as if you hadn’t doubled, and basic blackjack strategy will still apply.

As we’ve said, there are hard and soft hands in blackjack. To give you a bit more insight into what these hands look like in practice, here are some examples.

What are Hard Hands in Blackjack?

A hard hand in blackjack is a hand that doesn’t contain an ace. For example, 10 + 5 is known as a hard 15. Similarly, 10 + 2 + 4 is known as a hard 16.

What are Soft Hands in Blackjack?

A soft hand in blackjack is a hand that contains an ace. The reason it’s known as soft is because the total isn’t fixed due to the fact an ace can be worth 1 or 11. For example, A + 8 can either be worth 9 or 19. Similarly, A + 2 + 5 can be worth 8 or 18. The only time an ace can’t be worth 11 is when it would cause you to bust. For example, 10 + 9 + A would be worth 20 because the alternative would give you 30.

The Most Profitable Hands when Doubling Down

According to basic blackjack strategy, it’s more profitable to double hard hands than soft ones. The basis of this is that soft totals give you more flexibility so, by only electing to take one card, you’re scuppering that flexibility. Of course, that doesn’t mean you shouldn’t double down soft blackjack hands. However, in general, hard totals are better.

Building on this, doubling down on hands worth 10 or 11 is better than doubling on totals of 9 or 8 and so on. Finally, you need the dealer to be in a weak position if you want to have the best long-term expectation when pulling a blackjack double down.

Using a when to double down blackjack chart like the one in this guide is great. However, there may be times when you forget the optimal moves in every situation or you don’t have access to a chart. For these situations, it’s worth having a few rules of thumb to fall back on. Although these shouldn’t be seen as a substitute for charts or hard and fast rules, they should form the basis of any double down blackjack strategy.

✔Should: Your starting total is 11 and the dealer has a low card (e.g. 3, 4, 5, or 6). This is because you’re in a strong position and the dealer is weak.

❌Shouldn’t: The dealer’s up-card is an ace. In this spot, the dealer is in a strong position.

✔Should: You have a soft 16, 17, or 18 because you’re in a medium-strength position and can’t go bust.

❌Shouldn’t: You haven’t checked the dealer’s up-card. Asking when to double down in blackjack without considering the dealer’s card is a huge mistake. The answer is always a two-part equation that takes into account your hand and the dealer’s.

✔Should: You have a hard 10 and the dealer has 4, 5, or 6. Again, this is a position where you’re strong and the dealer is weak.

❌Shouldn’t: Your hand is worth more than 11. In this situation, you’re at risk of going bust and, therefore, shouldn’t double down.

✔Should: You have a total that’s worth hard 9 and the dealer has a 5 or 6. This is a situation where you’re fairly strong but the dealer is extremely weak. Therefore, doubling down is a positive move.

What is the risk of doubling down in blackjack?

The risk of doubling down is that you’ll lose double the amount you would have won if you can’t beat the dealer. Because you have to match your original bet when you make a blackjack double down move, you’re increasing your financial risk. However, if you learn when to double down in blackjack, you’re increasing your financial risk in an optimal spot. In other words, you’re betting more when you’re in a strong position.

Should players always double down on 11?

No. Although 11 is a powerful starting total, a when to double down in blackjack chart will tell you not to hit in all instances. The one time you shouldn’t double down with 11 is when the dealer is showing an ace. The reason for this is that the dealer is in a good position to either make blackjack (which would beat any hand you make) or a strong total.

Should players double down on 10?

Yes. In general, you should always double down on 10 when the dealer is showing a 2, 3, 4, 5, 6, 7, 8, or 9. Given that you can double with 10 against most dealer cards, you also have the option not to double. Even though the maths shows that this is a profitable long-term play, you may not want to take the risk of doubling. In reality, you should see the double down as an extra move and not a mandatory one.

How many cards do you get after doubling down?

One. The double down rules in blackjack are very clear on this: if you exercise this option, you only receive one card. Now, there are special circumstances where you can make moves after doubling down. However, these are rare.

Can you double down after splitting?

Yes, in some games. In general, you won’t be able to double down after splitting. However, there are some rulesets that allow you to do this. If you are allowed to double down after splitting, you should follow the standard blackjack rules outlined in this article.

You should also factor in the extra costs as you will have already paid to split your original hand (a pair). If you determine that doubling after a split is the right play, you can really press home your advantage and make some serious returns from a single round of blackjack.

Should you double down on a hard 12?

No. Blackjack double down is very clear on this. If you have a total over 11, i.e. a total where you can bust by taking a third card, you should never double down.

Should the dealer double down on a soft 17?

The dealer isn’t allowed to double down in blackjack. This is a special move that’s reserved for players. In fact, it’s one of the moves that gives you the chance to cancel out the casino’s edge. Although the dealer’s advantage is fairly small in blackjack (approx. 0.5%), the statistics say they’ll come out ahead in the long run. However, by implementing basic blackjack strategy and learning to make moves such as doubling down at the right time, you have the chance to reduce the house edge.

What does doubling down on soft count mean?

Doubling down on a soft number in blackjack means you’re paying to take an extra card when you’re starting hand contains an ace. As we’ve already said in this guide to doubling down in blackjack, soft hands are those that allow you to choose between two totals.

As mentioned previously, this is possible because aces can be worth one or 11. For example, A + 8 can be worth nine or 19. Therefore, when you double down on a soft count, you’re adding an extra card to a hand that contains an ace.

What does discard after double mean?

In some games, you may be able to “discard” or throw away your hand after doubling down. If you discard your hand, you’ll typically receive a portion of your total stake back (usually the double down bet).

In practice, the discard after doubling down rule is advantageous because you can limit your losses when the move doesn’t give you a strong total. However, this isn’t available in many games, so don’t expect to use it all the time.

To put your newfound double down betting strategy skills to the test, create your first account at Paddy Power Games and try our top online blackjack games today!

If you want more content like this, read our article on How to play Blackjack.