You're dealt a pair of 7s. The dealer shows a 4. Split or play it as one hand? Basic strategy answers:
| Split ← | +0.0105 |
| Stand | -0.2111 |
| Hit | -0.3349 |
| Double | -0.6698 |
| You bust on the next card | 46.2% |
| Dealer 4 busts | 39.4% |
Split is not close: it beats Stand by 0.2216 per unit. Getting this one wrong costs $2.22 on a $10 bet, every single time. Across the 340 situations in this chart it ranks 172nd by expected value — better than 168 of them, worse than 171. 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.
Against a dealer 4 (40% bust chance), splitting 7s turns one mediocre total into two playable hands while the dealer is vulnerable. With double-after-split allowed, you also keep the option to press each new hand — that's where the split profit comes from.