Blackjack Double Down Strategy

Double down is a blackjack rule that permits a player to make twice the bet and receive one card. Many blackjack tables permit doubling down on any first two cards. Some may limit doubling down to hard hands. Most blackjack tables allow double down after splitting pairs. 

There are a few blackjack games with unusual double down rules. Spanish 21, Super Fun 21, and Most Liberal 21 permit doubling down on 2, 3, or 4 cards, including after splitting a pair. Poker Palace in North Las Vegas, Nevada allows players to double down on 2 or 3 cards at its traditional game.

This article is part of a series. The previous post was about when to surrender in blackjack. 

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When to double down at blackjack 

The best double down strategy depends on the number of decks used. The list below shows when to double down at single-deck blackjack, double-deck, and tables that use four or more decks. The Wizard of Odds Blackjack Calculator was used to confirm the best blackjack double down strategy. 

Single-deck

These are the proper times to double down in single-deck blackjack. The first number represents the player’s hand. The second is the dealer’s face-up card. This list assumes the dealer hits soft 17. US Casino Advantage is unaware of any single-deck blackjack games that stand on soft 17 now that Black Gold is gone from Harrah’s Cherokee and Harrah’s Cherokee Valley River. 

• 8: 5 and 6
• 9: 2 to 6
• 10: 2 to 9
• 11: Any dealer card
• Soft 13, 14, 15, and 16: 4, 5, and 6
• Soft 17: 2 to 6
• Soft 18: 3 to 6
• Soft 19: 6

Double-deck

These are the times to double down in a double-deck blackjack game. The first list shows how to play when the dealer stands on soft 17. The other is when the dealer hits soft 17.

Four, six, and eight decks

Blackjack games with four, six, and eight decks all have the same double down strategy. The list below splits the options into whether the dealer hits or stands on soft 17 as that affects the decision. 

How to double down

In a live casino, players double down by placing an amount of chips equal to the original bet next to it. The player receives one card. It may be placed face up or down, depending on the type of game. Some casinos allow dealers to place the card down to keep the player in suspense, even if the game is dealt face-up. 

On an electronic table game or at an online casino, press the double down button. The card will be dealt automatically. 

Players may double down for less than the original bet at most live games. However, that is never the correct strategy. Doubling down for less is not available on electronic table games or at online casinos.  

Double down restrictions

Double down rules vary by casino. Some permit doubling down on any two cards. Others only allow it on hard 9, 10, and 11, or just 10 and 11. This prevents soft hands from being doubled. Most casinos allow players to double down after splitting any card but an ace. Others do not allow any double downs after splitting.

Beware of bad advice from regulated online gambling sites

Online gambling sites have every reason to give you bad strategy advice. One of the worst offenders is BetMGM. That company and others advise players to make the wrong move. For example, these companies never break down blackjack strategy by the number of decks. As shown above, that is important as it changes. This type of content also ignores whether the dealer hits soft 17 or not, which also affects the proper play.

The biggest mistake these sites make is on soft hands. Below are examples of these types of sites giving players bad advice on soft 16, 17, and 18. Here are some examples.