Hard 17 vs dealer ace: hit, stand, or surrender?
It depends on the soft 17 rule. If the dealer hits soft 17, surrender (stand if surrender is not offered). If the dealer stands on soft 17, stand.
- Dealer hits soft 17SurrenderIf surrender is not offered: stand
- Dealer stands on soft 17Stand
- Stand: take no more cards.
- Surrender: give up the hand at once for a smaller, fixed loss. Only as your first decision, and only where the table offers it.
Why
Dealer hits soft 17. Some hands are bad enough that surrendering half the hand beats playing them out. This is one of the few spots where cutting losses is the mathematically best play.
Dealer stands on soft 17. At this total, the chance of busting outweighs any gain from hitting. Let the hand stand as is.
Hard 17 means no ace is being counted as 11. Two-card ways to make it: 10 + 7, 9 + 8 (a 10 can be a 10, jack, queen, or king).
The numbers
- A dealer ace busts about 20% of the time when the dealer hits soft 17 and 17% when the dealer stands on soft 17, counted after the dealer has checked for blackjack.
- Taking one card on a hard 17 busts about 69% of the time.
| Dealer rule | 17 | 18 | 19 | 20 | 21 | Bust |
|---|---|---|---|---|---|---|
| Dealer hits soft 17 | 8% | 21% | 21% | 21% | 10% | 20% |
| Dealer stands on soft 17 | 19% | 19% | 19% | 19% | 8% | 17% |
| Play | Dealer hits soft 17 | Dealer stands on soft 17 |
|---|---|---|
| Surrender (where offered) | -0.50best | -0.50 |
| Stand | -0.51 | -0.48best |
| Hit | -0.58 | -0.56 |
| Double down | -1.16 | -1.11 |
Scoring: a win scores +1, a loss -1, a tie 0, and a doubled hand counts twice. Surrender scores -0.50. Hit means take a card, then play on as well as possible. These are averages over many hands from the strategy audit behind the app, rounded and approximate. Any single hand can go either way. Close call: the best play leads the next best by only 0.015 when the dealer hits soft 17 and 0.023 when the dealer stands on soft 17, so the next best play gives up very little.
Rules assumed
- 4, 6, or 8 decks (the chart is the same for all three)
- The dealer checks for blackjack when showing a 10 or an ace, before you act
- Double down is allowed on any first two cards
- Double after split is allowed
- Late surrender is offered, as your first decision only
- Split up to four hands; split aces get one card each and cannot be resplit
One-deck and two-deck games, tables without surrender, and dealers who do not check for blackjack change some plays. Check your table's rules before relying on any chart.
Both soft 17 rules are shown. The two charts differ on only 6 of 360 hands: see the dealer hits and dealer stands charts. The plays come from the verified 4 to 8 deck tables behind the Blackjack Trainer app (bs_4to8_h17_peek and bs_4to8_s17_peek).
Common questions: Hard 17 vs dealer ace
What is the correct play for hard 17 against a dealer ace?
It depends on the soft 17 rule. If the dealer hits soft 17, surrender (stand if surrender is not offered). If the dealer stands on soft 17, stand. Both assume 4 to 8 decks.
Does the soft 17 rule change hard 17 against a dealer ace?
Yes. If the dealer hits soft 17, surrender (stand if surrender is not offered). If the dealer stands on soft 17, stand. Only a handful of hands on the chart change with that rule, and this is one of them.
What if surrender is not offered?
If the dealer hits soft 17 and surrender is not offered, stand. If the dealer stands on soft 17, stand whether or not you can surrender. Late surrender is only offered as your first decision, after the dealer has checked for blackjack, and not every table offers it.
Why surrender with hard 17 against a dealer ace when the dealer hits soft 17?
When the dealer hits soft 17: Some hands are bad enough that surrendering half the hand beats playing them out. This is one of the few spots where cutting losses is the mathematically best play. When the dealer stands on soft 17: At this total, the chance of busting outweighs any gain from hitting. Let the hand stand as is.
Does the play change if hard 17 has more than two cards?
Yes. Double down and surrender are only available on your first two cards, so with three or more cards, stand.
Does this assume the dealer has already checked for blackjack?
Yes. In US-style games the dealer checks for blackjack when showing an ace before you act, so this play applies once the dealer is known not to have one. In games where the dealer does not check, some plays change.
Should I take insurance when the dealer shows an ace?
No. Basic strategy always declines insurance: insurance is a bad bet.
Does basic strategy guarantee a win?
No. It picks the play with the best average result, but any single hand can go either way, and the house keeps a small edge. This site and the Blackjack Trainer app are for practice only.