You're dealt a pair of aces. The dealer shows a 7. Split or play it as one hand? Basic strategy answers:
| Split ← | +0.4629 |
| Hit | +0.1655 |
| Double | -0.1839 |
| Stand | -0.4754 |
| You bust on the next card | 0.0% |
| Dealer 7 busts | 26.2% |
Split is not close: it beats Hit by 0.2974 per unit. Getting this one wrong costs $2.97 on a $10 bet, every single time. Across the 340 situations in this chart it ranks 52nd by expected value — better than 288 of them, worse than 51. 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.
Two aces are worth 12 together — a terrible total. Split, and each ace becomes the start of a hand worth ~52% of a blackjack. Splitting aces is the single most profitable move in the game, against any dealer card, including a 7.