You're dealt a pair of 7s. The dealer shows a 7. Split or play it as one hand? Basic strategy answers:
| Split ← | -0.0905 |
| Hit | -0.3213 |
| Stand | -0.4754 |
| Double | -0.6681 |
| You bust on the next card | 46.2% |
| Dealer 7 busts | 26.2% |
Split is not close: it beats Hit by 0.2308 per unit. Getting this one wrong costs $2.31 on a $10 bet, every single time. Across the 340 situations in this chart it ranks 212th by expected value — better than 128 of them, worse than 211. 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 7 (26% 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.