Blackjack Double Down Theory

There’s a common misconception, in my option, with doubling down in Blackjack. Many people feel that you should double down on 11 every single time. Is this really correct? How can any rule be applied 100% of the time? I don’t believe this rule for a minute. As a former Vegas dealer and gambler, I have seen countless people follow this rule into oblivion.

If I am playing Blackjack and the deck (or shoe) is pretty new, I will double down as long as the dealer is not showing an Ace or Ten. The deeper into the deck or shoe, I will stop doubling down on 11 when the dealer is showing a 9 or higher or an Ace. But here’s why rules are not meant to be followed blindly. Let’s say you are playing single deck Blackjack, the deck is down to the last hand or two and you’ve just been dealt 11. The dealer is showing a 7. You remember seeing a good deal of high cards already. Should you double down?

Blackjack Double Down

The answer, in this example, is no. Small cards favor the dealer. Also, if the rest of the deck is comprised mostly of small cards, you will be doubling your wager for a possible 12-16. That’s not good when the dealer will most likely end up with a 17 or greater. Think about this. In a brand-new deck, you have a 50% probability to finish with 18 or better when you double down on 11. If the dealer is showing a 9, 10 or face, you will may need 19 or better just to tie. That drops you under a 50% probability.

The point is that you should try to keep a general idea about the remaining cards in your head. You don’t need to be a card counting wizard. Just think about what you have seen and figure out if the remaining cards are more of the higher or smaller variety. Once you do that, then decide on doubling down. It should never be automatic—especially when the dealer is showing a high card.