Blackjack Strategy for Doubling Down
When I started writing Blackjack Strategy for Doubling Down, I remembered a session playing a $5 Blackjack table at Arizona Charlie’s in Las Vegas years ago. It was late, and my bankroll was dwindling. So I decided to double a $25 bet, with only $100 left. The basic strategy said yes, I did, and I won. I went to bed with money in my pocket – life was good!

Doubling Down?
One of the most challenging decisions beginning Blackjack players face is “Doubling Down.” Doubling Down is simply placing another wager on your hand equal to your initial bet, and for this wager, you will receive another card. However, like all Blackjack strategies, you should only use this option when the perfect strategy calls for it.
There are many variations in blackjack rules. Some are even distinct to locale. I first saw “surrender” rules in Atlantic City. Casinos usually display the house rules on a small sign at the dealer’s side and tell you when to double down your hand.
888CasinoBlog – A Great Resource
According to 888CasinoBlog, an excellent blackjack strategy website, “most casinos allow you to double down on any two-card hand (hard or soft), whereas some restrict doubling to specific starting hands, e.g., doubling is allowed only on hard 10 and 11.” Doubling down on any two cards is the best player-friendly doubling allowed.
The basic strategy for doubling down is for beginning players at a six-deck shoe. Taken from Al Moe’s article “Six Keys to Winning At Blackjack.”
Hard Hands
- 9 – double against a dealer 2 through 6 and hit 7 through ace
- 10 – double against a dealer 2 through 9
- 11 – double against a dealer 2 through 10
Soft Hands
- 16 and 17 – double against a dealer 2 through 6; otherwise, hit
- 18 – double against a dealer 2 through 6, stand against a 7 or 8, hit against 9, 10, or ace
Other considerations include:
- # of decks used
- dealer’s up card
- Hard hands vs. soft hands ( for example – a soft 18 = A, 7; a challenging 18 would be 10, 8)
- Doubling on low pairs (4,4 or 5,5) considering a single deck vs. 4-8 deck shoe.
Blackjack Strategy for Doubling Down – Plus Resource Links
As I continued to look at strategy cards & Blackjack websites, I realized that I could not give the many viewpoints and advanced strategies needed to know beyond a basic strategy of doubling down. So, as an added resource to get it right, I have provided an article by Henry Tamburin, Ph.D., famous for his Ultimate Blackjack Strategy Guide:
Best Blackjack Strategies
If you’re serious about winning more when you play blackjack, I encourage you to utilize the Best Blackjack Strategies I’m about to share with you.
Note: The following strategies can be used in all games unless stated otherwise. The strategies discussed below assume you are a recreational player, not a card counter. Abbreviations used in this article are:
- S17 = Dealer must stand on soft 17
- H17 = Dealer must hit soft 17
- DAS = Doubling down after pair splitting is allowed
- NDAS = Doubling down after pair splitting is not allowed
ALWAYS DOUBLE DOWN ON A HARD 11 –
- You’ll always win more money if you double down on hard 11 against any dealer’s upcard vs. hitting in all games, with one exception. If you are playing a multi-deck game when the dealer must stand on soft 17, you are slightly better off hitting against a dealer Ace rather than doubling down.
ALWAYS SPLIT A PAIR OF 8s AND ACES –
- You should always split a pair of 8s and Aces regardless of the dealer’s upcard.
- (Note: If surrender is offered and you are playing in a multi-deck game with H17 or a double-deck game with H17 and NDAS, your best strategy is to surrender the pair of 8s vs. the dealer’s Ace rather than splitting them.)
NEVER SPLIT A PAIR OF 5s OR TENS –
- Consider a pair of 5s is also a hard 10. You are better off taking a one-or-more-card draw to a ten than splitting the 5s and playing two hands, each starting with a 5.
ALWAYS HIT A HARD 12 AGAINST A DEALER’S 2 OR 3 UPCARD –
- This is a situation where most players chicken out and stand on their 12 because they fear busting. Against a dealer’s 2 or 3 upcards, you will lose money in the long run whether you stand or hit. However, you will lose less money by hitting, even at the risk of busting sometimes.
ALWAYS HIT ACE-7 (SOFT 18) WHEN THE DEALER’S UPCARD IS 9, 10, OR ACE –
- Players mistakenly believe that a hand that totals 18 is a sure win, which is why they stand on soft 18 (A-7), especially when the dealer is showing a “strong” upcard (e.g., 9, 10, or Ace). The facts are these.
- If you draw any of the four ten-valued cards, you do no harm to the hand. Your best strategy is consistently hitting A-7 when the dealer shows a 9, 10, or Ace. The goal is getting to either a soft 19–21 or a hard 17 through 21.
- (Note: In the case of a single-deck game with S17, you are slightly better off standing on A-7 when the dealer’s upcard is an Ace.)
ALWAYS DOUBLE DOWN ON 10 WHEN THE DEALER’S UPCARD IS 9 OR LESS –
- You are the favorite when you hold a two-card ten against any dealer’s upcard of 9 or less. This is why doubling down is your best strategy. It’s a simple rule: always double down on 10 when the dealer’s upcard is nine or less.
IF THE RULES SPECIFY THAT THE DEALER MUST HIT SOFT 17, YOU SHOULD ALWAYS DO THE FOLLOWING:

- Always double down on hard 11 against the dealer’s ace,
- soft 19 (A-8) against dealer’s 6, and
- A-7 against the dealer’s 2
ALWAYS DOUBLE DOWN A-2 THROUGH A-7 WHEN THE DEALER’S UPCARD IS A 5 OR 6
- In all games, you stand to win more if you always double down an A-2 through A-7 (i.e., soft 13 through 18) when the dealer’s upcard is a 5 or 6, making it the best strategy.
ALWAYS STAND WITH A PAIR OF 9s WHEN THE DEALER’S UPCARD IS A 7
- Most players know to split a pair of 9s when the dealer’s upcard is nine or less. Where they fumble the ball is when the dealer shows a 7. Your best strategy is to stand because you’ll win slightly more money than splitting.
- One way to remember this best strategy is as follows. There is a good chance that the dealer will have a ten in the hole. Therefore, when the dealer’s upcard is a 7, she often has a 17. Your pair of 9s, an 18, would beat her potential 17, making standing the better play.
ALWAYS SURRENDER HARD 16 AGAINST A DEALER’S 9, 10, OR ACE UPCARD. THE SAME FOR HARD 15 AGAINST DEALER’S 10 UPCARD
- A challenging 15 and 16 are two of the worst hands in blackjack, especially when the dealer shows a strong upcard (e.g., 9, 10, or Ace). You are the underdog, but you can minimize losses by surrendering the above hands against the indicated dealer’s upcards. Surrendering is your best strategy simply because it saves you money in the long run.
DEALT A PAIR OF 2s OR 3s AGAINST A DEALER’S 2 OR 3 UPCARD? SPLIT IF THE RULES ALLOW DAS, AND HIT IF THEY DON’T
- The reason splitting is the better strategy with DAS is that if you split, say, a pair of 2s and draw a 9 giving you an 11, or an 8, giving you a 10, you would be able to bet more money (by doubling down) in a very favorable situation.
STAND ON HARD 16 AGAINST A DEALER’S 10 UPCARD IF YOUR 16 IS MULTI-CARD
- The traditional blackjack basic strategy only considers the player’s hand and the dealer’s upcard total. With a hard 16 against a dealer’s ten upcards, the strategy states to hit (assuming surrender is not offered).
- Although correct, you can improve your playing accuracy by considering whether your 16 is a multi-card 16. In the latter case (e.g., 7-5-4), your best strategy is to stand against a dealer’s ten cards.
NEVER PLAY A 6 TO 5 BLACKJACK GAME

- Many casinos pay a winning player’s blackjack at only 6 to 5 odds. (A $10 wager would win you only $12 in a 6 to 5 game.) The house edge increases by about 1.45% in a single-deck game with 6 to 5; moreover, if 6 to 5 is offered in a double- or multi-deck game, the house edge escalates to greater than 2%. Your best strategy is to play only blackjack games with a 3 to 2 payoff.
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