Blackjack basic strategy can reduce the house edge to a slight 0.5% over time, but only if you follow it perfectly and make the correct decisions. That includes not only when to hit and when to stand, which most new blackjack players learn right away, but also when to double and split, among other decisions. In this series we are analyzing the reasons for the doubling down strategy. In today’s blog, I’m covering what to do when you have a soft 17.
If you are dealt a soft 17 with your first two cards (ace, 6), you should double down if the dealer shows a three through six as an upcard. If the dealer shows anything else, you should hit. You should never stand with a soft 17, because it is only an average hand and there is no risk of busting if you try to improve your hand.
Blackjack basic strategy takes into account that there are more cards in a deck with a value of 10 than any other value. Therefore, the odds are with the dealer having a 10 in the hole and a 10 being drawn when you or the dealer hit.
Taking that into account, if the dealer shows a three though a six, he is likely to have a 13-16. These are stiff hands that are likely to bust. If the dealer has a hard 13, there are only five cards (4, 5, 6, 7, 8 ) that will help his hand, five cards (9, 10, J, Q, K) that will bust him and three cards (ace, 2, 3) that will leave him with another stiff hand (14-16). If the dealer has a hard 14, there are only five cards (3, 4, 5, 6, 7) that will improve his hand, six cards (8, 9, 10, J, Q, K) that will bust him and two cards (ace, 2) that will leave him with another stiff hand (15-16). If the dealer has a hard 15, there are only five cards (2, 3, 4, 5, 6) that will improve his hand, seven cards (7, 8, 9, 10, J, Q, K) that will make him bust and one card (ace) that will leave him with another stiff hand (16). Finally, if the dealer has a hard 16, only five cards (ace, 2, 3, 4, 5) will improve his hand, while eight cards (6, 7, 8, 9, 10, J, Q, K) will bust him.
Therefore, with each of these hands there are 8/13 odds against the dealer – odds that he will either bust or draw a stiff hand. What about your soft 17, though? What happens when you take another card? When you hit a soft 17, there are four cards (ace, 2, 3, 4) that will improve your hand. The other nine cards will leave you with a lower total than you started, after your ace is turned from an 11 to a one. For that reason, there are 9/13 odds that after you take a card, you will want to take another one.
However, if you double down you can only take one card and cannot hit again. For that reason, you should only double down on hands when you think the dealer is going to bust, which includes any of the stiff hands (13-16). In this case, you’re not doubling because you think you’ll end up with a great hand by taking another card. You’re doubling because if the dealer busts, you win even with a bad hand.
Blackjack basic strategy works both in brick and mortar casino and in online casinos.