A concise working definition of a hard hand in single deck blackjack is a hand that hasn't a single ace on it. They're called hard hands since some hands in this group have a good possibility of going over a total of 21. An example would be a hard 17, this can be made up of a ten value card and a seven or an eight and a nine (not an ace and a six).
Like every other blackjack strategy, the first thing you need to check, of course, are your own cards and compare them with the dealer's cards. Given that information we make the following decisions in a game of blackjack:
Hard 17 to Hard 21: Given these hands the only correct move is to stand whatever the dealer has for an up card.
Hard 16: The correct move is to stand on the dealer's two to six up card and to hit given that the dealer shows seven to ten or an ace.
Hard 15: You play this hand the same way you play a Hard 16.
Hard 14: The correct strategy for this hand total is the same as that of the Hard 16 hand.
Hard 13: You should play this hand the same as a Hard 16.
Hard 12: The correct strategy for this hand is to hit if the dealer shows an up card of two, three, seven, eight, nine, ten, or an ace. Stand if the dealer shows an up card of four, five or six.
Hard 11: Since we're playing single deck blackjack, the correct strategy for a hard 11 is to double down. It doesn't matter what card the dealer has. This is one of the advantages of a single deck we can take advantage of.
Hard 10: The correct strategy when playing this hand in blackjack is to double down on the dealer's up card from two to nine, everything else you should hit for a good hand.
Hard Nine: The correct move for this hand in blackjack is to double down on a two to six dealer up card. Next is to hit on your dealer's seven up card to a ten up card, same thing goes for an ace.
Hard Eight: The correct play is to hit given that the dealer's card is from two to four, seven to ten, or an ace. If it is a five or a six then the correct play is to double down.
Hard Five to Hard Seven: Keep hitting until you get a good hand.
This is the strategy for single deck blackjack hard hands. Take time to practice them in order to gain an advantage over the house.