Double Down in Blackjack
Updated
Doubling down means putting out a second bet equal to your first in exchange for exactly one more card. One card, and then your turn is over no matter what lands. It is the most profitable play in the game when the conditions are right, and it is usually right on a hard 9, 10, or 11 against a dealer who is showing weakness.
- You double the bet and get exactly one card. No more.
- Hard 11, 10, and 9 are the main doubling hands.
- Soft hands (A,2 through A,7) double against a weak dealer.
- DAS means you can also double after splitting a pair.
Hard hands: when doubling pays
| Your total | Double against | Otherwise |
|---|---|---|
| 11 | 2 through 10 | Hit against an ace |
| 10 | 2 through 9 | Hit against 10 and ace |
| 9 | 3 through 6 | Hit against everything else |
Six decks, dealer stands on soft 17. If the dealer hits soft 17, you also double 11 against an ace. That one cell is the most common difference between charts you will find online, and it is why you should know which rule your table uses.
Eleven is the standout. Roughly 31% of the deck is worth ten, so a single card turns your 11 into a 21 almost a third of the time, and into 19 or 20 much of the rest. There is no better moment to have twice as much money on the felt.
Soft hands: doubling with an ace
Soft doubles confuse people because the totals look weak. A,3 is a 14, and doubling a 14 sounds reckless.
It is not, and the reason is that you are not really betting on the 14. You are betting against a dealer who is about to bust. Soft doubles show up only against upcards 3 through 6, which are exactly the hands the dealer breaks 37% to 42% of the time.
- A,2 and A,3: double against 5 and 6.
- A,4 and A,5: double against 4, 5, and 6.
- A,6: double against 3 through 6.
- A,7: double against 3 through 6. Stand against 2, 7, and 8. Hit against 9, 10, and ace.
A,7 is worth a second look. It is a soft 18, which feels like a hand you should keep, and against a 7 or an 8 you do keep it. Against a 3 through 6 you double, and against a 9 or higher an 18 is not good enough, so you take a card and try to improve.
Double after split
DAS means the house allows a double on a hand created by splitting a pair. It is worth about 0.14% to you, and it also changes several splitting decisions, since being able to double the resulting hands is what makes some marginal splits pay. The list is in when to split.
How doubling changes at a high count
Counters add doubles that basic strategy leaves alone. Ten against a ten, and 9 against a 7, both become doubles once the true count gets high enough, because a shoe full of tens makes the one-card draw far more likely to land where you want it.
Our live counter shows the exact true count each deviation switches on at, in progressive mode.
The mistakes people actually make
- Not doubling 11 against a 10. It looks scary and it is correct. Sitting there hitting your 11 is a real, measurable leak.
- Doubling on a total that is not 9, 10, 11, or a listed soft hand. Doubling a 12 because you feel due is how bankrolls disappear.
- Forgetting that one card is all you get. Double a hard 9, catch a 2, and you are standing on 11. That is part of the deal you took.
- Doubling for less. Some houses let you double for less than your original bet. If the play is right, put the full amount out. If you cannot afford the full amount, the table is too big for you.
• Double means twice the bet and exactly one card.
• 11 against 2 through 10, 10 against 2 through 9, 9 against 3 through 6.
• Soft hands double only against a weak dealer.
• Under H17, 11 doubles against an ace too.
What does double down mean, exactly?
After your first two cards, you place a second bet next to the first and the dealer gives you one card, usually turned sideways so the pit can see the hand is closed. You cannot hit again, and you cannot surrender.
Most American casinos let you double on any two cards. Some restrict it to totals of 9, 10, and 11, or even to 10 and 11 only, which costs you 0.09% and 0.18% respectively. That is on the placard, and it is worth reading before you sit down. The full price list is in the rules to check.
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By Martin Kosek · every number on this site is computed by us, not copied.
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