You're dealt a pair of 5s. The dealer shows a 8. Split or play it as one hand? Basic strategy answers:
| Double ← | +0.2866 |
| Hit | +0.1979 |
| Split | -0.3440 |
| Stand | -0.5105 |
| You bust on the next card | 0.0% |
| Dealer 8 busts | 24.5% |
Double is worth 0.0887 more per unit than Hit. On a $10 bet that is $0.89 handed over every time you get it wrong. Across the 340 situations in this chart it ranks 84th by expected value — better than 256 of them, worse than 83. 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 pair of 5s is really a hard 10 — one of the best doubling totals in the game. Splitting would create two hands starting from 5, the worst possible start. Against a 8, play it as 10: double down and press your edge.