Hard 12 against a dealer 3
This is one of the closest decisions in blackjack. Hit is correct, but it beats stand by 1.86% of your bet — and of the 350 hand-versus-upcard spots on the chart, only 20 are closer.
Worth being blunt about what that expected return means: at -23.4%, you lose money on this hand in the long run whatever you do. Playing it correctly does not make it a good spot — it makes it a 1.86% less bad one. The choice is between two losing options, which is exactly why it gets argued about.
Every option, ranked
| Action | Expected return | Cost vs. best |
|---|---|---|
| Hitcorrect | -23.37% | — |
| Stand | -25.23% | −1.86% |
| Double | -46.74% | −23.37% |
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.
The house rules do not change it
For all the argument this hand attracts, the answer is stable: every one of the 6 rule sets modelled gives the same correct play. What changes is how much it costs you, not what to do.
| S17 · 3:2 | Hit | -23.4% |
| H17 · 3:2 | Hit | -23.4% |
| S17 · Surrender | Hit | -23.4% |
| S17 · No DAS | Hit | -23.4% |
| S17 · No Peek | Hit | -23.4% |
| S17 · 6:5 | Hit | -23.4% |
Why it is close
Taking a card on hard 12 busts you 30.77% of the time. Standing hands the hand to a dealer showing 3, who — having already checked and not got blackjack — busts 37.4% 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
Hit 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 +1.27, so past that point stand is the better play — a deviation conventionally written as an index of +1.
This one is on Schlesinger’s Illustrious 18, the deviations that return the most to a counter, where it carries an index of +2, one step from what this engine arrives at independently.
Where that number comes from, and what one card of each rank is actually worth, is on the card counting page.