Every other card in blackjack is worth one number. The ace is worth two — one or eleven — and it switches between them on its own, whichever keeps you at 21 or under. A hand that is currently counting an ace as eleven is called soft. A hand with no ace, or an ace forced down to one, is hard. The difference is the most under-used piece of information at the table.
What “soft” buys you
A soft hand cannot bust on the next card. Take ace-6, a soft 17. Draw a ten: instead of 27, the ace drops to one and you hold 17. Draw a 4: you hold 21. There is no card in the deck that ends the hand. The worst a draw can do to a soft total is leave you with a hard total you would have been happy to hit anyway.
That is why a soft hand is not the same as a hard hand of the same number. Hard 17 is a hand you stand on because drawing risks a bust. Soft 17 is a hand you can improve for free. Treating them alike throws the free draw away.
The totals worth knowing
Soft 13 to 17 (ace with 2 through 6). Always take a card. You cannot bust, and a stood 13-to-17 loses to almost any dealer hand. Against a dealer showing 4, 5 or 6, doubling is often better still — see when to double down.
Soft 18 (ace-7). The one that catches people. An 18 feels finished, and against a dealer showing 2, 7 or 8 it is: stand. But against a 9, 10 or ace, an 18 loses more often than it wins, and since drawing cannot bust you, take the card. Against 3 through 6, double.
Soft 19 and 20. Stand. Improving is possible but unlikely, and a 19 or 20 already beats most of what the dealer makes.
Where soft goes hard
Draw enough and the ace has to become a one. Ace-6, hit with a 9, is no longer a soft 17: it is a hard 16, and it now plays by the hard rules — stand against a weak dealer card, hit against a strong one. Keep track of which side of the line you are on; the same three cards can be a soft hand one draw ago and a hard one now.
The dealer's soft 17
The rule cuts both ways. At our tables the dealer hits a soft 17 rather than standing, for the same reason you should: the draw is free and usually improves the hand. It makes the dealer slightly stronger than at a stand-on-17 table — a fraction of a percent on the house edge — and it is why a dealer showing an ace or a six is a little more dangerous here. The full dealer script is in why the dealer's fixed rules are the house edge.
One last thing the ace does at our tables: paired with a ten on your first two cards it is a Pontoon, paid 3:2 on the spot. Soft 21 is the only soft hand you never have to think about.
