You're dealt a pair of 4s. The dealer shows a 6. Split or play it as one hand? Basic strategy answers:
| Split ← | +0.1460 |
| Hit | +0.1150 |
| Double | +0.0870 |
| Stand | -0.1537 |
| You bust on the next card | 0.0% |
| Dealer 6 busts | 42.3% |
Split is worth 0.0310 more per unit than Hit. On a $10 bet that is $0.31 handed over every time you get it wrong. Across the 340 situations in this chart it ranks 115th by expected value — better than 225 of them, worse than 114. 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 6 (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.