Soft 18 against a dealer 2
This is one of the closest decisions in blackjack. Stand is correct, but it beats double by 0.20% of your bet — and of the 350 hand-versus-upcard spots on the chart, only 2 are closer.
Every option, ranked
| Action | Expected return | Cost vs. best |
|---|---|---|
| Standcorrect | 12.17% | — |
| Double | 11.97% | −0.20% |
| Hit | 6.29% | −5.88% |
Expected return per unit staked, from an exact recursive engine rather than a copied chart. Figures are for Dealer Stands on Soft 17, DAS, pays 3:2. Actions not shown are not legal here.
It genuinely depends on the house rules
“It depends” is usually a dodge. Here it is literally true: under 1 of the 6 rule sets modelled, the correct play is something other than stand.
| S17 · 3:2 | Stand | 12.2% |
| H17 · 3:2 | Double | 11.5% |
| S17 · Surrender | Stand | 12.2% |
| S17 · No DAS | Stand | 12.2% |
| S17 · No Peek | Stand | 12.2% |
| S17 · 6:5 | Stand | 12.2% |
Why it is close
Standing hands the hand to a dealer showing 2, who — having already checked and not got blackjack — busts 35.4% of the time. Two bad numbers close together is the whole story — the decision is a choice between them, and neither rescues the hand. The bust odds page has both curves in full.
What the count does to this
Stand is correct at a neutral shoe, but not at every shoe. The two actions are worth exactly the same at a Hi-Lo true count of +0.84, so past that point double is the better play — a deviation conventionally written as an index of +1.
Where that number comes from, and what one card of each rank is actually worth, is on the card counting page.