Soft 17 in Blackjack

Land tables print the rule on the felt in one of two forms. Dealer must stand on all 17s, sometimes written as draw to 16 and stand on all 17s, is the S17 game: soft or hard, a 17 ends the dealer's hand. Dealer must hit soft 17 is the H17 game. Online, the same line sits in the rules or help screen, often abbreviated to S17 or H17.

A table that prints only the instruction to stand on 17, without the word all, leaves the question open, and the rules screen settles it. Two games with the same name can differ on this line, so the check belongs to each table rather than to a title or a studio.

Six decks. Each figure is the chance that the dealer's hand, drawn under the usual rules, arrives at a soft 17 at some point: the moment where S17 and H17 tables part ways. On every other hand the two rules play out identically.

A soft 17 is an ace counted as 11 plus other cards worth exactly six. With a 7, 8, 9 or 10 already showing, the cards that are not aces add up to at least seven, so an ace counted as 11 would push the hand to 18 or more. Behind those upcards the rule never comes into play, and the dealer's results are the same at an S17 and an H17 table.

The ace is the opposite case. It already supplies the 11, so any combination worth six behind it completes a soft 17, which is why the ace leads the table at 11.09%. A 6 needs only one ace to arrive. A 5 is the rarest low card, at 0.57%, because the remaining one point has to come from a second ace counted as 1, as in A,A,5.

The key point: Soft 17 decides anything only behind a 2 through 6 or an ace. Facing a 7 or higher, the rule card makes no difference to the dealer's hand.

A six-deck shoe, with percentages covering all dealer hands behind the upcard. Behind the ace the rest of the hands, 30.87% of them, are dealer blackjacks, which the rule does not touch. These two upcards are where the rule bites hardest; a 2 through 5 shifts only slightly, since the dealer seldom reaches soft 17 behind them.

Drawing to soft 17 does make the dealer bust more often. Behind a 6 the bust rate climbs from 42.28% under S17 to 43.93% under H17, and over all upcards from 28.19% to 28.58%. The extra busts are not the whole story. The first card drawn to soft 17 cannot bust it: it either lifts the hand to 18 through 21 or turns it into a hard 12 to 16 that must draw again, and a large share of those hands end on a total above 17.

That trade runs against the player. A finished dealer 17 beats only player hands of 16 or less and pushes a 17. Turned into 18 or 19, it beats a standing 17 or 18 as well. The extra dealer busts, meanwhile, pay only hands still standing, and every player hand that busted has already lost before the dealer draws.

In short: Hitting soft 17 adds a few dealer busts but many more dealer totals that beat a standing hand, and the second effect is the larger.

Each row keeps the other reference rules, with a natural paid 3:2 and doubling on any two cards, split hands included, and assumes the matching basic strategy. The cost barely moves with the size of the shoe, and the six-deck figure is the one the dealer-hits-soft-17 row carries in the rule table on the blackjack odds page. On one deck the stand-on-soft-17 game leaves the player ahead by 0.14%, and hitting soft 17 is enough to hand the edge back to the house.

Six decks; every figure is what the hand returns on average, in units per 100 staked, under the rule named at the head of its column. Of every cell in the chart, these 3 are the only ones the rule changes; everything else is played the same at both tables.

All three cells were near ties under S17, and each sits where the extra dealer card matters. With 11 against an ace, hitting leads doubling at an S17 table; under H17 the ace stops on 17 far less often and busts more, which is enough to put the double in front. Soft 18 against a 2 is closer still, with standing a fraction of a unit ahead of the double, and the dealer's added busts tip it. Soft 19 against a 6 follows the same logic against the upcard most likely to reach soft 17 among the low cards.

None of the three changes is large on its own, and playing the S17 chart at an H17 table gives away only small amounts. Using the right chart still matters, and both versions are printed side by side in the basic strategy guide. A dealer who hits soft 17 also lengthens the list of hands worth giving up where surrender is offered, from 4 to 7, as the blackjack surrender page shows.