Double Down Option

Inexperienced players often wonder how is it possible to win at blackjack in the long term when their probability of winning a hand in a fair game is approximately 44%. Well, one of the main reasons why this is possible is the player’s ability to get more money into action when they hold an advantage against a dealer who is in trouble.

One way to increase your action in favorable situations is to double down, in which case you post an extra bet that should be equal in size to your initial stake. In exchange, you get one additional card and are no longer able to hit your hand. The dealer would either tuck the extra card under your chips in pitched games or place it sideways next to your initial two cards in a multiple-deck game.

Doubling down can indeed be risky since it involves increasing your bet. This causes clueless or more conservative players to altogether avoid this play out of fear they might end up losing twice as much money on a single hand. Others tend to overdo it, exercising the double down option each time their “intuition” tells them they stand to win a hand.

Yet, doubling down can be one of the most thrilling and profitable moves you can make at the blackjack table, but only on condition you are able to identify the advantageous situations that call for a bet increase. In this article, we tackle doubling down rule variations and give you further insight into some of the key doubling decisions that can help you maximize your profits.

Doubling Down Rule Variations

mobile blackjack imageThe tricky thing about this play is that the rules related to doubling down may vary wildly in different casinos, which is why you should be well-acquainted with the doubling rule variations you may encounter. These are not written on the table’s felt so you will either have to ask the dealer for specifics or stand by and observe others play for a while.

In many multiple-deck games, players are permitted to double on any starting two-card total without further restrictions. This is the most player-friendly rule variation because it gives you the opportunity to potentially turn a profit in all advantageous situations you face.

This is not the case in some casinos where players are restricted to doubling only on specific two-card totals, particularly on hard 9, 10, and 11, which increases the house edge by 0.09%. Some venues would even restrict doubling to totals of 10 and 11 only which gives the house edge a boost of around 0.18%.

The “Free” Double Down Rule

blackjack strategyWe previously explained the player is normally required to increase their bet up to the amount of their original stake. In some casinos, however, there are blackjack tables where the so-called “free double down” rule applies. This variation of the game is known as Free Bet Blackjack and was invented by Geoff Hall, the same guy who came up with Blackjack Switch.

Free Bet Blackjack debuted in the summer of 2012 at the Golden Nugget Casino in downtown Las Vegas and immediately attracted crowds of eager blackjack players because it gave them the opportunity to double down on the house, i.e. without the need of posting additional wagers.

Instead, the dealer places a lammer next to your original wager to mark your double down. If you win, the dealer will pay you both for your initial bet and your double. Should you lose, you lose only your original bet.

You probably think this sounds too good to be true and indeed, you are right. The main catch here is that players are restricted to doubling at no cost only on totals of 9, 10, and 11. When the dealer draws to a total of 22, they do not bust like they normally would. Instead, they push with you if your total is 21 or lower. Add the H17 rule and the absence of surrender to the mix and you have the house edge for this game jump to 1.04% with basic strategy.

Doubling Down on Three Cards or More

variationsAt some blackjack tables, players are given the option to double on three cards or more, which is great because it translates into even more opportunities to turn extra profits. Suppose, for example, you start your hand with two cards that add up to 7 against a dealer 5 and then you draw a 4 for a total of eleven.

It would be impossible to double down at this stage in a regular game of 21. However, if you are playing a blackjack variation that allows for doubling on three or more cards, you will be able to fully exploit your dealer’s weakness by doubling on your three-card 11 and potentially pocketing an extra payout.

This rule variation is an absolute rarity, of course, but do not hesitate to take advantage of it if you do happen to come across one such table – this rule takes away around 0.20% of the casino’s edge.

Doubling Down for Less

Doubling Down for LessIn some gambling establishments, blackjack players are permitted to double down for less than their initial bet. For example, if you wager $20 on a hand suitable for doubling down, you can double for an amount smaller than $20, like $15 or $10. It is typical for some conservative or underbanked players to take advantage of this rule variation.

Should you do it, though? No, doubling down for less is not a good idea. This decision is contrary to what doubling is all about. Players can maximize their profits only by reaching deeper into their pockets and increasing their double down bets to the full permissible amount at the table.

Let’s consider the following situation to better demonstrate how stupid doubling for less than your original bet really is. Suppose you post a $10 bet and are dealt a nice starting total of 11 against the dealer’s Queen, which, as you know, is assigned a value of 10 like all other face cards. You have several options here, excluding standing since not drawing more cards on your 11 is contrary to all logic.

You can hit your hand, double down for the full amount of your bet or double down for less. Hitting a starting total of 11 against a dealer 10 results in a win around 56% of the time. Therefore, your average expectations with a total of 11 are to win roughly 56 out of every 100 hands, ties excluded. With a $10 bet, this accounts for overall profits of $560, overall losses of $440, and net profits of $120 over the course of a hundred hands.

Blackjack Rules and Moves Explained


Doubling on Soft Hands vs. Doubling on Hard Hands

soft and hard handsWe explained on a couple of occasions that a blackjack dealer ends up winning a bit more frequently than the player whose probability of winning hands in a fair game is around 44% as opposed to the dealer’s 47% probability of winning. The remaining 9% account for the occasions when the dealer and the player push.

From this perspective, it makes sense for the player to bet more conservatively on the majority of the hands they go through. However, this is not the case when it comes to doubling down on hard totals where you should play more aggressively, increasing your action if the dealer has a relatively high likelihood of exceeding 21 and you have an edge over their hand.

Some people would settle for their soft totals and dismiss both hitting or doubling on such hands because they are too afraid they may end up getting stuck with a lower total by drawing an additional card. This fear causes them to pass on many lucrative opportunities to increase their action when holding an advantage against the dealer.

Others wrongfully assume the reason why basic strategy recommends doubling on certain soft totals is that you try to outdraw the dealer. But if you take a quick look at the basic-strategy chart, you will see doubling is a viable option with soft totals only when the dealer is exposing a weak card.

In other words, you double on hands like A-4 and A-5 against the dealer’s 4, 5 or 6 because they are more likely to bust with these small cards and you want to get as much money into action as you can against a vulnerable dealer.

When Your Double Down Goes Wrong

Double DownDoubling down can be very profitable but it can also be very tricky for the simple reason you are entitled to draw only one extra card. When doubling on soft hands, you may get stuck with a lower total than the one you started with.

Similarly, if you double down on a hand like 7-2 against the dealer’s 5, you draw a 2 or a 3 for poor totals like 11 or 12. The only way for you to win the round would be for the dealer to break their hand. You would have been able to hit your hand repeatedly if you had not doubled. And yet, doubling is the correct play in one such scenario. Continue reading to see why.

Insight into the Key Doubling Down Decisions

Basic strategy tells blackjack players when it is the best time to hit, stand, split, or double down. It is based on mathematical probability and millions of computer-simulated trials, which guarantees the plays it comprises are the optimal ones in the long run. Let’s examine several situations where doubling down is the best course of action and explain why.

Doubling on a 9 against a Dealer with a Small Card

DoublingWe talked about how sometimes doubling down can get you into trouble but remains the best play nevertheless. This is the case when you are dealt a hard 9 against a vulnerable dealer who exposes a small card like 5. In one such scenario, you will win roughly 59% of the time and lose around 41% of the hands, i.e. if we do not include the pushes.

Thus, if you flat bet $10 and play the same hand a hundred times, you can expect to win $590 and lose $410 for overall net profit of $180. The average profit you generate per hand with this play is $180/100 = $18.

Your win rate for the hand drops down to around 57% when you double down but this difference is offset by the fact that you are winning twice as much when executing this play. Your average net profit per hand in this instance is equal to ($570 – $430) * 2 = $280/100 = $28. As you can see, you win $10 more per hand, which is why doubling on your hard 9 against the dealer’s small card is the best course of action.

Doubling on a 10 against a Dealer with a Small Card

DoublingWe already discussed the subject of doubling on an 11 against a dealer’s 10 and the prolific effect it has in terms of net winnings. Now, let’s consider an example where you double on a 10 against a dealer with a small card, 4 for example.

Regardless of the composition of your hard 10 (8-2, 6-4, 5-5, 7-3), the mathematical probability of you winning with this move is roughly 58% whereas that of you losing is around 35%, with the remaining 7% accounting for the ties where no money switches hands (respectively there are no net profits). Let’s suppose you have wagered $10 on this hand and are playing a multiple-deck game where the S17 rule applies.

If you decide to merely hit your hard 10 and draw a small card 2 through 7, you are not supposed to draw again anyway because the basic strategy for the game you are playing recommends you to stand on hard totals 12 through 17 when the dealer exposes a 4.

Doubling on Soft 13 through 18 against a Dealer with a Small Card

strategyInexperienced players often struggle with soft totals, especially when doubling down is concerned. They are too scared they might ruin their soft hand by drawing a card that reduces its total and turns it into a stiff. They argue this is way too risky and may cost them twice as much money if the double down is unsuccessful.

However, in certain situations when the dealer is at a disadvantage, basic strategy requires you to double down on your soft hands, particularly when the dealer is weak with small cards 3 through 6. Here is a brief breakdown of the doubling rules for soft hands 13 through 18 for a multiple-deck game where the dealer stands on soft 17. If doubling is not allowed on any two cards, proceed by hitting or standing depending on your total and the dealer’s upcard.

  • Double on soft 13 and soft 14 against a dealer 5 or 6, otherwise hit
  • Double on soft 15 and soft 16 against a dealer 4, 5, or 6, otherwise hit
  • Double on soft 17 against a dealer 3, 4, 5 or 6, otherwise hit
  • Double on soft 18 against a dealer 3, 4, 5 or 6, otherwise stand

Let’s now examine an example with a soft 17 against a dealer with a 4 to see the exact differences in the net profits when you hit and double. Whether you hit or stand has no impact on the outcome of the hand itself because there is no card you can possibly draw that will cause you to make another hit. In the worst possible scenario, you will end up drawing a 5 for a hard total of 12 and stand against the dealer’s 4 in accordance with basic strategy.

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Find the answers of questions people asked so far:

Dan Alejandra

When is doubling down not an optimal move in blackjack?

Asked by: Alejandra | Asked on: 2023-08-07
Answered by: Dan | Answered on: 2023-08-08

When you are playing blackjack, it is best to base your doubling-down decisions on basic strategy. That said, I can give you a few scenarios when doubling down is not considered to be the right move to play in blackjack. Avoid doubling down when you have a weak hand total, especially when it is below 9 or a hard 12 to 16. Doubling down on these hands puts you at a high risk of going over 21 and busting.

It’s generally not advisable to double down when the dealer is showing 7 through Ace since a dealer’s strong upcard indicates that they have a good chance of having a solid hand. It is advisable to avoid doubling down on soft hands totaling 19 or 20 (Ace-8 or Ace-9). These totals are already strong, and taking the risk to double down might not give you the advantage you are looking for.

Some casinos may not allow you to double down on the resulting hands after you have split Aces. Even if you are allowed to double down, it’s generally not recommended to do that action on split Aces, as you have a higher chance of drawing a low-value card, which will turn your soft hand into a hard hand.

Dan Jessica

Do I need to memorize the hands when the basic blackjack strategy advises to double down?

Asked by: Jessica | Asked on: 2023-11-19
Answered by: Dan | Answered on: 2023-11-20

Memorizing every optimal move according to the basic blackjack strategy can be a difficult task, especially for unseasoned players who are just starting to learn how to play the game. That is why one can find numerous websites that offer strategy charts that are adjusted to the ranging rules in blackjack. As doubling down may be suitable on a specific hand in blackjack with fewer decks than in versions using eight decks, it is important to find the correct basic blackjack strategy chart.

While it may not be very appropriate to use a chart to make your doubling down decisions when you play blackjack at a land-based casino, when you play the game online, it is totally acceptable to resort to such cheat sheets to help you learn the correct situations when doubling down is the optimal move in blackjack.