You hold a hard 7 (no ace counted as 11). The dealer shows a 4. Here is the mathematically correct basic-strategy play — and why.
| Hit ← | -0.0430 |
| Stand | -0.2111 |
| Double | -0.2823 |
| You bust on the next card | 0.0% |
| Dealer 4 busts | 39.4% |
Hit is not close: it beats Stand by 0.1680 per unit. Getting this one wrong costs $1.68 on a $10 bet, every single time. Across the 340 situations in this chart it ranks 191st by expected value — better than 149 of them, worse than 190. 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.
A dealer 4 only busts about 40% of the time — most of the time they'll finish with 17 or better. Standing on hard 7 just waits to be beaten. Even though hitting busts you 0% of the time, improving your hand is the lesser risk against a strong dealer card.
Think of it this way: your 7 almost never wins as-is against a made dealer hand. The hit isn't reckless — it's the only path to a total that can actually win.