Blackjack Strategy: When to Double Down

Jamie Casey

March 19th, 2019

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Doubling down is one of the most thrilling moves in blackjack. It allows you to double your bet in the middle of a hand in exchange for one extra card. It’s a risky gamble, as it usually ends your betting - if you receive a particularly low second card you can’t hit again.

This can lead to more timid players avoiding the double bet, and more adventurous players making it far too often. It's important to try and strike a balance between sensible safe play and risky double downs in order to maximise your potential winnings.

When to Double Down

Fortunately, basic strategies for blackjack have been meticulously mapped using mathematical probability, designed to tell you exactly when is best (in the long run) to double down. There are three situations when it’s best to double down, explained below.

In all of these situations you can’t go bust and are in the most likely position to finish with a high hand, while statistics indicate that the dealer is in the most likely position to lose the hand.

Hard 9 Against the Dealer’s Low Cards

When you are dealt a total of 9, double down when the dealer shows a card between 2 and 6 (any card below 7, not including the Ace). This must be a hard 9; meaning there is no Ace in your hand – so the combinations could be 2-7, 3-6 or 4-5. If you have A-8 (a soft 9), it’s best to stand, regardless of what the dealer shows.

Soft 16 To 18 Against the Dealer’s Low Cards

If you have an Ace and either a 5, 6 or 7 giving you a ‘soft’ total of 16 to 18 and the dealer shows a card from 2 to 6, this is a great time to double your bet. With an Ace and a lower card (2 to 4) it is better to just hit, as you are less likely to end with a high hand.

Hard 10 Or 11 Against Any Lower Dealer Card

A hard 10 or 11 puts you in a powerful position – that is, with any two cards, not including an ace, that make 10 or 11 (2-8, 2-9, 3-7, 3-8, 4-6, 4-7, 5-6). If the dealer has a lower total, it's time to double down.

Pay Attention to the Rules

In almost every Blackjack game this strategy should stay true. However, be aware that the rules of Blackjack do vary between casinos, which can affect your decision making. If it’s possible to double with 3 or more cards, then you may find additional hands when you could double down, so pay attention to your total.

On the other hand, you might find situations where the rules say you can’t double when the strategy says you should – such as on soft hands (those with an Ace). If you can’t double down when you'd like, be sure to hit instead. To try this double down strategy out in a cash game before hitting a real-life casino, head over to Winner Casino today!