Blackjack Doubling Down
Doubling Down on Soft Hands
When compared to doubling down on hard hands, the potential gain from doubling down on soft hands is fairly modest. The average player, if they even double on soft hands, generally make so many error that they do not see any benefit at all. A Basic Strategy player will expect to see only a .14% profit. Not only are mistakes made, but many casinos limit doubling down on soft hands to the point that it is all but prohibited. These casinos limit doubling down to hard totals of 9, 10, and 11. Most of these casinos will allow you to double on (Ace, 8), but if you draw a two, your total is 11 and not 21. You may be inclined to consider doubling down on soft hands unimportant given this information and that it is not important to study. There are a large number of players learning to play blackjack that feel this way. Unfortunately this is not the case. Blackjack is a difficult game to beat, and the only way to survive and prosper is to fight for every possible edge. So whenever you are presented with the opportunity to double down on soft hands it is important that you use it to maximum advantage. Doubling down on soft hands is possibly the easiest Basic Strategy option to learn.In fact, when doubling down on soft hands the most difficult thing about is not remembering when to do it, but understanding why you want to do it. The logic behind doubling down when you have an 11 is easy to understand. However the logic behind doubling down on soft hands like (Ace 2) or even (Ace, 7) is more difficult to understand. Unfortunately the key to understanding this logic is not as intuitive as you might find when doubling down on hard hands.
Generally speaking the differences between doubling down on soft hands compared to hard hands can be expressed as one of emphasis. For instance we generally expect to win the hand by achieving a higher hand total when we double down on hard hands. On occasion the dealer busts, even when we end up with a low total and we still win. But the primary emphasis in hard doubling is attaining a powerful hand. When doubling down on soft hands the emphasis is reversed. For example with a hand of (Ace 2) vs. 6, there is the chance that we might draw an 8 which would be extremely lucky and fortuitous, but that is not the primary goal for doubling down on soft hands. We are really betting that the dealer will bust and it won’t make any difference what total we end up with. It is for this reason that doubling down on soft hands, unlike doubling down on hard hands, is only done when the dealer is showing a bust card and is therefore likely to bust as he draws to complete his hand.
To make this comparison easier to understand, let’s consider a concrete example. Basic Strategy says to double down with hard 11 vs. the dealer’s 6. Suppose we make this play 1 000 times in an infinite deck game. What would be the expected result? Computer studies have shown that, on the average, we would end up with the following totals:
| Hand Total | Probability |
| 21 | 308 times |
| 20, 19, 18, or 17 | 77 times each |
| 16 or less | 384 times |
The dealer, by contrast, would end up with the following totals;
| Hand Total | Probability |
| 21 | about 98 times |
| 20 | about 101 times |
| 19 or 18 | about 106 times each |
| 17 | about 167 times |
And the dealer could expect to bust about 422 times.
With the dealer busting 422 times we would win outright 422 times. And with the dealer achieving a 17 or higher 578 times, we could expect to achieve a tie 67 times and beat him 211 times.
So, in 1 000 trials, doubling down with hard 11 vs. the dealer’s 6, we could expect to win about 633 times. And of these 633 wins, 211 of them, would be the result of outdrawing the dealer.
Now let is consider what happens when we double down on soft hands. Again we will assume a infinite deck. Naturally the dealer’s probabilities will remain the same as the dealer’s play has not changed. As a player our probabilities have drastically changed. We would make the following totals when doubling down on soft hands;
| Hand Total | Probability |
| 21 | about 77 times |
| 20, 19, 18, or 17 | about 77 times each |
| 16 or less | 615 times |
Like in the example for hard hands we still win the 422 times that the dealer busts. But now we tie the dealer 45 times and only beat the dealer 100 times out of the 578 times the dealer makes a hand.
So in 1 000 trials we now figure to win 522 times. Of these 522 wins, only 100, are the result of outdrawing the dealer.
As we can see the implications are obvious: when doubling down on hard hands, even though wins through dealer busts are important, the emphasis is on outdrawing the dealer; however when doubling down on soft hands, winning by outdrawing the dealer are important the emphasis is clearly on the dealer busting.
No all doubling down on soft hands are the same, with an Ace 7 or Ace 8 hand we are much more likely to end up with a pat hand. However this is offset by the fact that we started out with a decent hand and doubling down in this case may mess it up. So still the emphasis is on the dealer busting.
Of course doubling down on soft hands is only done when the dealer has a very good chance of busting his hand.
Basic Strategy
| Player Hand | Dealer’s up Card | |||||||||
| 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | Ace | |
| A,8 | S | S | S | S | D | S | S | S | S | S |
| A,7 | S | D | D | D | D | S | S | H | H | S |
| A.6 | D | D | D | D | D | H | H | H | H | H |
| A,5 | H | H | D | D | D | H | H | H | H | H |
| A,4 | H | H | D | D | D | H | H | H | H | H |
| A,3 | H | H | D | D | D | H | H | H | H | H |
| A,2 | H | H | D | D | D | H | H | H | H | H |
| Legend: | |
| H | Hit |
| S | Stand |
| D | Double |
