You hold Ace-9 — a soft 20, meaning the ace still counts as 11. Dealer shows Ace. The correct basic-strategy play:
| Stand ← | +0.6555 |
| Hit | +0.0814 |
| Double | -0.0140 |
| You bust on the next card | 0.0% |
| Dealer Ace busts | 16.7% |
Stand is not close: it beats Hit by 0.5740 per unit. Getting this one wrong costs $5.74 on a $10 bet, every single time. Across the 340 situations in this chart it ranks 23rd by expected value — better than 317 of them, worse than 22. Expected value is per unit staked, computed for multi-deck, dealer stands on soft 17, double after split allowed. The model and the code are published as data.
Soft 20 (Ace-9) is already a strong total. Against a dealer Ace, drawing risks turning a winner into a weak hand, and there's no doubling edge worth chasing here. Stand and take your equity.
Soft hands are where most casual players leak the most: they play them like hard totals and miss every profitable double. Learning the six soft-total rows of the chart is the fastest win-rate upgrade there is.