Decision Library
Hard 15 vs dealer 10 · six decks · dealer stands on soft 17 · double after split allowed
Correct play
SurrenderEvery option loses money; -0.500 per unit is the smallest loss, and surrendering beats hitting by 0.005 per unit.
Deals a hard 15 against a dealer 10 in the trainer, graded live.
Per unit bet, six decks, dealer stands on soft 17, computed by the engine.
| Option | EV / unit | vs. best |
|---|---|---|
| SurrenderBest | -0.500 | — |
| Hit | -0.505 | -0.005 |
| Stand | -0.541 | -0.041 |
| Double | -1.011 | -0.511 |
Hard 15 against a 10 is one of the few hands so bad that giving up half your bet beats playing it out. Surrender locks in a -0.500 result. Every other option here does worse than that.
The best you could do by playing is hitting at -0.505 per unit, which is 0.005 worse than the half-bet you keep by surrendering.
Surrender feels like quitting, so players refuse it and play the hand out. Against a 10 that refusal is expensive. Standing and playing it out costs 0.041 per unit versus the correct surrendering. 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) | Surrender |
| 6 decks, hits soft 17 | Surrender |
| Single deck, stands soft 17 | Surrender |
| Double deck, stands soft 17 | Surrender |
| No surrender offered | Hit changes |
The correct play changes under: No surrender offered. Everywhere else, surrender holds. Use the row that matches your table.
Strategy and expected values from a combinatorial engine validated against Wizard of Odds.