Smart Blackjack Play: When and How to Double Down
The feeling of doubling down in blackjack is one of the greatest in the game; looking at your eleven against that dealer six, knowing you have an almost two-thirds chance of winning, is a real rush. But it’s important to know when to use that blackjack double-down option.
Proper use of doubling down in blackjack increases your odds. © Tommy Video, Pixabay
What is Double Down in Blackjack
Blackjack is one of the lowest house advantage games that you can play. A good two-deck game with good rules is less than a 0.5% house edge. That means for every $100 you bet, you only lose 50 cents in theory. Compare that with the average slot machine 94% Return to Player, where every $100 you bet costs you on average $6, and you can see why many people are drawn to the game.
For better or worse, blackjack requires a basic strategy to get those numbers. You can’t just wildly play your hands the way you wish. There is an actual mathematical model for each set of rules and number of decks that need to be followed.
Fortunately for us, those basic strategy rules are easily summed into a chart. On that chart, you can look at your hand total and the dealer’s up card and see what you should do quickly and easily. This is simply called a basic strategy chart, and you can download one from Google for free or buy a simple laminated one at most casino gift shops.
Unlike those slot machines we mentioned earlier, there are times when we know that we have the advantage that the house lets us add to our bet. One of those is splitting; if we have, for instance, a pair of 8s’ our basic strategy chart will tell us that most times we need to split them because it allows us to add a second hand, and in this case, with an eight, we are likely to have the advantage.
In other cases, like tens, it will tell us never to split because our one hand already has a strong twenty and is likely to get paid, whereas if we split those tens, we may end up with two 16s and lose both hands due to our greed.
Doubling down in blackjack is a very similar idea; we want to add to our bet when we have the advantage. But we want to use our blackjack double-down strategy correctly.
Proper Use Of Blackjack Double Down Strategy
Most casinos allow you to double down on at least some of your two-card totals, but the top blackjack sites online and the best brick-and-mortar casinos will have their rules set where you can double on any two cards, not just some combinations of them.
But it is definitely a rule worth checking before you begin your blackjack play. A casino that only allows you to double on 9-11 has increased its odds against you by .1%. This may not sound like much, but it adds more than 20% to the overall house edge in a good double-deck game.
In this same game, if the casino only allows you to double on ten or eleven, your basic strategy house edge with a cut card in play goes from .45% to .69% or an increase of over 50%. So it is obviously well worth your time to track down games with double after any two cards.
Another key double-down blackjack rule is doubling after splits. If we have that pair of eights mentioned earlier and we get a two or a three against a dealer six, we want to get even more money than just our split on the table; we want to be able to double after splitting. There are many other such instances.
Again, in our very good double deck game, the rule change on double after split could see the House edge go from .45% to slightly over .60% or almost a third higher casino advantage. Nobody needs to lose their hard-earned money 33% quicker, so pay attention to house rules and look for double after split, as well as double any two cards.
Regarding when you should double, it is best to get a basic strategy chart that matches the rule set and number of decks in use. Then you can never go wrong whether you are playing on the subway on your phone on one of your many casino apps or sitting down at the Bellagio or Borgata at a hundred-dollar table.
You are free to use these basic strategy charts anywhere, and they ensure that you play at the very best house edge, which means you get to play longer, earn more comps, and stand a better chance at having more winning sessions.
If you are just looking for some basic rules of thumb, we can help you with that, though the soft double downs can be tricky to remember. A hard double-down is simply one that doesn’t include an ace. So, for instance, a five and a four are a hard double. But an ace and an eight are not the same thing as it could be worth nine or nineteen, remembering that the ace can be counted as a one or eleven.
So a hard nine is always doubled against a dealer’s up card from two through six cards totaling ten that don’t include an ace are doubled against a dealer’s upcard between two -through nine, and two cards totaling eleven are usually always doubled.
In our ideal double-deck game, which we discussed earlier, the difference between what soft hands are doubled and which ones aren’t has many different changes depending on whether the dealer hits their soft seventeen or not.
We have found that about 90% of DD games now hit soft 17, so we will quickly cover these rules, but please be aware that soft doubles are one of those hands where you will really wish you had taken our advice and gotten a basic strategy card when it comes blackjack double down strategy.
We won’t ever double down with an ace/nine, and we will only double with an ace/eight against a dealer six. But with an ace/ seven, we want to double against a dealer two through six, and with an ace/six, we will double against a three through six. If we have an ace/five, ace/four, or ace/three, we only double against a four through six, and the ace/two only gets doubled against a five or six.
Remember, we told you to get a card with the proper blackjack double-down strategy printed on it. And don’t forget that much of the low house edge in blackjack comes from getting more money in the circle when we have the advantage; that is something that is seldom seen in other casino games, so make sure and take full advantage of it.
In blackjack, the edge isn’t just in the math—it’s in knowing when to press it. And doubling down, when done right, is the closest thing to a potential win you can find in the pit.
