Decision Library
Hard 9 vs dealer 3 · six decks · dealer stands on soft 17 · double after split allowed
Correct play
DoubleYou keep a positive expectation of +0.132 per unit here, and doubling beats hitting by 0.025 per unit.
Deals a hard 9 against a dealer 3 in the trainer, graded live.
Per unit bet, six decks, dealer stands on soft 17, computed by the engine.
| Option | EV / unit | vs. best |
|---|---|---|
| DoubleBest | +0.132 | — |
| Hit | +0.107 | -0.025 |
| Stand | -0.246 | -0.378 |
| Surrender | -0.500 | -0.632 |
Hard 9 against a 3 is a doubling hand: you are a favorite to improve to a strong total on one card, and the dealer's 3 is weak enough that putting more money out is worth it.
Doubling returns +0.132 per unit against +0.107 for a plain hit. The extra 0.025 is the value of the doubled bet on a hand where you expect to win more often than not.
Hitting wins the hand often enough that players forget to put the extra bet out. Skipping the double leaves money on the table. Just hitting instead of doubling costs 0.025 per unit versus the correct doubling. Over a few hundred of these hands, that is real money handed back.
Same hand, different table conditions. The correct play holds unless noted.
| Table condition | Correct play |
|---|---|
| 6 decks, stands soft 17 (baseline) | Double |
| 6 decks, hits soft 17 | Double |
| Single deck, stands soft 17 | Double |
| Double deck, stands soft 17 | Double |
| No surrender offered | Double |
The play is stable: double is correct across deck counts, the soft-17 rule, and whether or not surrender is offered.
Strategy and expected values from a combinatorial engine validated against Wizard of Odds.