You're dealt a pair of 4s. The dealer shows a 5. Split or play it as one hand? Basic strategy answers:
| Split ← | +0.0803 |
| Hit | +0.0708 |
| Double | +0.0035 |
| Stand | -0.1672 |
| You bust on the next card | 0.0% |
| Dealer 5 busts | 41.6% |
Split beats Hit by 0.0095 per unit staked. Small, but it is the same small edge in every shoe you ever play — and it compounds over a lifetime of hands. Across the 340 situations in this chart it ranks 143rd by expected value — better than 197 of them, worse than 142. 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 5 (42% bust chance), splitting 4s 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.