What Doubling Down Means and When the Chart Says to Do It

Doubling down in blackjack means you double your bet after you see your first two cards, and then you get exactly one more card. Basic strategy doubles on hard 9, 10 and 11 and on some soft hands, mostly when the dealer's face-up card is a low card such as a 5 or 6.

• What Does Double Down Mean in Blackjack?
• Blackjack Double Down Rules
• When to Double Down: Hard 9, 10 and 11
• When to Double Down on Soft Hands
• Why the Chart Doubles 11 Against a 6
• When a Double Is a Mistake
• Double for Less
• Practice Your Doubles

01What Does Double Down Mean in Blackjack?

To double down means you add a second bet, equal to your first bet, after you see your first two cards.

In return, the dealer gives you exactly one more card. After that card, your hand is finished.

Here you have a 6 and a 5 for a total of 11. The dealer's up card (the dealer's face-up card) is a 6.

1. You bet 10 and get a 6 and a 5.
2. You press Double. Another 10 goes on the table, so your bet is now 20.
3. You get one card. If it is a 9, your total is 20.
4. The dealer plays the dealer's hand.
5. If your total beats the dealer's total, or the dealer busts, you are paid 1:1 on the full 20.
6. If the dealer's total beats yours, you lose the full 20.

02Blackjack Double Down Rules

Online tables show their rules on the table screen or in the help menu. These are the double down rules you will see most often.

• First two cards only. You can double only before you take any other card. After a hit, the Double button disappears.
• One card only. After a double you get one card, and you cannot hit again.
• Extra bet up to your first bet. The extra bet can match your first bet. Some games also let you add less.
• Double on any two cards. Many online games let you double on any first two cards.
• Double on 9 to 11 or 10 to 11 only. Some games allow doubling only on these totals. Doubling on 10 and 11 only adds about 0.20 percentage points to the house edge (the share of each bet the casino keeps on average).
• Double after split. When you split a pair (two cards of the same value) into two hands, many games let you double on each new hand. A game with no double after split adds about 0.14 percentage points to the house edge. See when to split.

Here is a hand where the table rules matter. Hard 9 against a 4 is a double in the chart, but a game that allows doubling on 10 and 11 only does not let you double it.

In most online games the dealer checks for blackjack before you play, so you never double into a dealer blackjack. Games with no hole card (the dealer's face-down card) handle this differently, as explained on the European blackjack page.

All the other table rules are on the blackjack rules page.

03When to Double Down: Hard 9, 10 and 11

A hard hand is a hand with no ace, or with an ace that counts as 1. Basic strategy (the chart of the best move for every hand) doubles hard 9, 10 and 11 against certain up cards.

These cells read double, otherwise hit. If the game does not let you double, take a hit instead.

Victoria's tip

Play a pair of 5s as hard 10. The chart never splits two 5s; it doubles against 2 to 9 and hits against 10 and A.

The full chart is on the blackjack strategy chart page.

04When to Double Down on Soft Hands

A soft hand has an ace that counts as 11. The ace counts as 11 unless that would take the hand over 21; then it counts as 1, so one card cannot bust a two-card soft hand.

The chart doubles soft hands only when the dealer shows a low up card, from 2 to 6.

For A,2 to A,6, if you cannot double, hit. For A,7 and A,8, the cells read double, otherwise stand, so if you cannot double, stand.

05Why the Chart Doubles 11 Against a 6

With 11, many of the cards left in the shoe (the box the cards are dealt from) are worth 10: the 10, J, Q and K. Any one of them gives you 21.

The dealer's 6 is the up card that busts most often. Busting means going over 21.

With a 6 showing, the dealer busts about 43.9% of the time. With a 10 showing, the dealer busts about 21.2% of the time.

These numbers are counted before the dealer checks for blackjack, so a dealer blackjack counts as a hand that did not bust.

The average result is what each unit of your first bet returns over many hands. This hand has a positive average result, so putting a second bet on it gives the bigger number.

06When a Double Is a Mistake

Double only in the cells where the chart says double. These are common doubles the chart does not make.

• Hard 12 to 19. The chart never doubles these totals.
• Hard 5 to 8. Hit against every up card.
• Hard 9 against 2 or against 7 to A. Hit.
• Hard 10 against a 10 or an ace. Hit.
• Soft A,7 against 9, 10 or A. Hit; do not double.
• Soft A,9. Stand against every up card.
• A pair of 10s. Stand on 20 against every up card.

A pair of 10s against a 6 is 20. The chart stands; it does not double and it does not split.

Victoria's tip

If your hand is not in a double cell of the chart, do not double. A bigger bet on a weak total only means you lose more when the hand loses.

07Double for Less

Some online games let you double for less. You add an extra bet that is smaller than your first bet.

You still get only one card. The chart's double moves assume you add the full amount.

Here you bet 10 on hard 11 against a 5. A full double adds 10; a double for less adds a smaller amount, such as 5.

• A double for less puts less money on the hand in the spots where the chart wants more money on it.
• The average results in the table above are for a full double, not a partial one.
• If a full double is more than you want to bet, lower your starting bet on the next hands instead.

Victoria's tip

Pick a starting bet that leaves room for a full double. Then you can follow the chart on every hand.

08Practice Your Doubles

Basic strategy, doubles included, lowers the house edge to about 0.62% under standard rules. It does not remove the house edge.

Try this hand: soft A,6 against a 4. The chart says double, otherwise hit.

1. Learn the double cells for hard 9, 10 and 11 first.
2. Add the soft doubles from A,2 to A,8.
3. Practice the hands in the blackjack trainer until you answer without checking the chart.
4. See how the double rules change the house edge in the house edge calculator.

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