You're dealt a pair of 5s. The dealer shows a Ace. Split or play it as one hand? Basic strategy answers:
| Hit ← | +0.0814 |
| Double | -0.0140 |
| Split | -0.5572 |
| Stand | -0.6670 |
| You bust on the next card | 0.0% |
| Dealer Ace busts | 16.7% |
Hit is worth 0.0955 more per unit than Double. On a $10 bet that is $0.95 handed over every time you get it wrong. Across the 340 situations in this chart it ranks 142nd by expected value — better than 198 of them, worse than 141. 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 Ace, play it as 10: the dealer is too strong to double, so just hit.