Blackjack Dealer Rules (S17 vs H17)
Updated
The dealer has no freedom at all. They draw until reaching at least 17, then stop. They cannot double, split, or surrender, and they cannot deviate for any reason. That rigidity is exactly why the game can be solved, and it is what basic strategy is built on.
- Dealer draws to 16, stands on 17. No decisions, ever.
- S17 stands on soft 17. H17 draws to it, and costs you about 0.20%.
- The dealer cannot double, split, or surrender.
- The house edge comes from acting last, not from better cards.
The rule, in full
The dealer shows one card and keeps a second face down. After every player has finished, they turn the hole card over and draw until their total reaches 17 or more, then stop. If they go over 21, every player still standing wins.
There is no judgment involved. A dealer holding 16 against your visible 20 must draw, even though it is obvious to everyone at the table what is about to happen. A dealer holding 17 against your 20 must stand, even though standing guarantees a loss.
What S17 and H17 mean
S17 means the dealer stands on a soft 17, an ace plus a six. H17 means they take another card. Everything else about the rule is identical.
H17 is worse for you, by roughly 0.20% of house edge. That sounds trivial and is not. It is the second most important item on the felt after the blackjack payout.
The rule also changes how you play, which people forget. Under H17, three soft hands play differently, and the loudest one is A‑8 against a dealer 6: you stand under S17 and double under H17. If you find a chart online that tells you to double soft 19, you are looking at an H17 chart. We break out every difference in what H17 changes.
What each upcard actually makes
This is the table worth internalizing, because basic strategy is nothing more than a response to it. Six decks, S17, computed after the dealer has checked for blackjack, so these are the odds you actually face once the hand continues.
| Upcard | 17 | 18 | 19 | 20 | 21 | Busts |
|---|---|---|---|---|---|---|
| 2 | 14.0% | 13.4% | 13.0% | 12.4% | 11.8% | 35.4% |
| 3 | 13.4% | 13.1% | 12.5% | 12.1% | 11.5% | 37.4% |
| 4 | 13.1% | 12.4% | 12.1% | 11.6% | 11.2% | 39.6% |
| 5 | 12.2% | 12.2% | 11.8% | 11.2% | 10.8% | 41.8% |
| 6 | 16.6% | 10.6% | 10.6% | 10.2% | 9.7% | 42.3% |
| 7 | 36.9% | 13.8% | 7.8% | 7.9% | 7.4% | 26.2% |
| 8 | 12.9% | 36.0% | 12.9% | 6.9% | 7.0% | 24.4% |
| 9 | 12.0% | 11.7% | 35.2% | 12.0% | 6.1% | 22.9% |
| 10 | 12.1% | 12.1% | 12.1% | 36.8% | 3.8% | 23.0% |
| A | 18.8% | 18.9% | 18.9% | 18.9% | 7.7% | 16.7% |
Computed by exact recursion over a six-deck shoe with cards removed as they are drawn, conditioned on the dealer not already holding a natural. Method in how we calculate.
Two things jump out of that table.
First, the dealer bust rate peaks at 42.3% on a 6 and drops off a cliff at 7. That is the line the whole chart is drawn along: 2 through 6 are dealer weakness, 7 through ace are dealer strength. It is why you stand on 12 against a 4 and hit the same 12 against a 7.
Second, a dealer 5 and a dealer 6 are only about half a percent apart in bust rate, but a dealer 2 busts barely more often than one time in three. "Dealer shows a small card" is not one situation, it is a range.
When exactly must the dealer draw?
Always on 16 or less. Never on hard 17 or above. On soft 17 it depends on the table rule, and the dealer cannot break it in either direction, not to help you and not to hurt you.
This is worth knowing because new players sometimes think a dealer is choosing to punish them. Nobody at the table has less freedom than the person dealing.
Can the dealer double or split?
No. Doubling, splitting, and surrender belong to you alone. The dealer plays one hand, mechanically, to 17.
On paper that is a large disadvantage for the house. They give up every flexible tool in the game and keep none of them. They make it back with one structural advantage: they act last. If you bust, your bet is collected immediately, before the dealer draws a single card. When the dealer busts on the very next card, it does not matter. Your money is already gone.
That one asymmetry is the entire house edge in blackjack. Everything else in the rules is trimming around it.
Which dealer rule should you look for?
S17, without hesitation. It saves you about 0.20% compared with H17, which puts it second on the list of things to check at a table, behind only the 3:2 payout.
The practical order when you walk up to a table: confirm blackjack pays 3:2, confirm the dealer stands on all 17s, then look at doubling and splitting rules. The full price list is in the rules to check before you sit down, and there is more on how it all adds up in blackjack odds.
Keep reading
By Martin Kosek · every number on this site is computed by us, not copied.
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