Decision Library
Hard 15 vs dealer 9 · six decks · dealer stands on soft 17 · double after split allowed
Correct play
HitThe best you can do is hold the loss to -0.473 per unit, and hitting beats surrendering by 0.027 per unit.
Deals a hard 15 against a dealer 9 in the trainer, graded live.
Per unit bet, six decks, dealer stands on soft 17, computed by the engine.
| Option | EV / unit | vs. best |
|---|---|---|
| HitBest | -0.473 | — |
| Surrender | -0.500 | -0.027 |
| Stand | -0.543 | -0.070 |
| Double | -0.952 | -0.479 |
Hard 15 is too low to leave alone against a 9. Standing surrenders the hand to a dealer who reaches a pat total most of the time, so you take the card. Your bust risk on the hit is 53.7%, and against this upcard that risk is worth accepting.
Hitting returns -0.473 per unit versus -0.543 for standing, a +0.070 swing in favor of taking the card.
It is tempting to stand on 15 and hope the dealer busts, but against a 9 that hope is too thin. Standing costs 0.070 per unit versus the correct hitting. 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) | Hit |
| 6 decks, hits soft 17 | Hit |
| Single deck, stands soft 17 | Hit |
| Double deck, stands soft 17 | Hit |
| No surrender offered | Hit |
The play is stable: hit 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.