You have 5 + 6 against a dealer 10. After a check has excluded dealer blackjack, Double has the highest expected value (EV). Without that check, Hit is better under the rules below.
Begin with a fresh eight-deck shoe. Enter your 5, the dealer’s 10, then your 6. The dealer stands on soft 17, doubling is allowed on any two cards, and surrender and Cash Out are disabled. The dealer has a reserved, unknown hole card in both examples.
Keep Dealer blackjack settlement: All bets lose. Example A uses Peek A / 10 after a no-blackjack check. Example B uses Ace peek only, so there is no check against this 10. These are constructed practice states calculated with Advantage Count v1.
Best action EV per original wager.
8 decks · S17 · all bets lose to dealer blackjack
| Action | A · after no-BJ check | B · no check on 10 |
|---|---|---|
| Hit | +0.1188 | +0.0321 |
| Stand | −0.5416 | −0.5771 |
| Double | +0.1788 | +0.0100 |
One unit is the original bet. Double puts two units at risk, but its EV still uses that original unit as the reference. In B, Double remains positive at +0.0100; Hit simply has the higher value at +0.0321.
02 / THE INFORMATION AT THE DECISION
The hidden card is still hidden.
A peek checks for a two-card dealer blackjack. Against a 10, a no-blackjack result tells you the hole card is not an Ace. It does not reveal its rank or remove every Ace from the shoe. You can still draw an Ace.
Before the check, 32 Aces remain among 413 unknown card identities, including the reserved hole card. The dealer-blackjack probability is 32 ÷ 413 ≈ 7.75%. In A, that possibility has already been excluded. In B, it is still part of each action’s EV.
This is also why two EV tables can disagree when they use different dealer-check assumptions. The Wizard of Odds expected-value tables explicitly distinguish values after a no-blackjack peek from no-hole-card values that include losses of added wagers.
03 / WHAT HAPPENS TO THE SECOND UNIT?
Double exposes an extra wager.
In B, imagine drawing a 10 to make 21, then seeing the dealer reveal an Ace. Your three-card 21 is not a natural blackjack. With All bets lose, the dealer’s natural beats it.
| Your action | Total wager | Net result |
|---|---|---|
| Hit | 1 unit | −1 unit |
| Double | 2 units | −2 units |
This is one possible settlement, not an expected result. Across all outcomes, the extra dealer-blackjack loss is enough to move Double below Hit in this example.
Follow the Double calculation
Weight the no-blackjack value by 381/413, and the two-unit blackjack loss by 32/413:
(381/413) × (+0.178769…) + (32/413) × (−2) ≈ +0.0100 units.
The calculation uses unrounded values. This decomposition applies to the specified hand and settlement rule.
What changes with Original bet only (OBO)?
Change only B’s settlement setting to Original bet only (OBO). In the app’s model, the added Double unit is returned against dealer blackjack for this non-busted hand. The chosen reveal then loses one unit, despite a two-unit wager.
The calculated Double EV rises to +0.0874, above Hit’s +0.0321, so Double becomes best again. A single card cannot bust this starting 11. Do not extend the refund to busted hands: the app’s OBO model still loses their full wager.
04 / THREE PROCEDURES, TWO QUESTIONS
No peek and no hole card describe different things.
Ask when the dealer takes a second card, and whether blackjack is checked before the player acts. The app exposes these procedures:
| Setting | Second card | Early blackjack check |
|---|---|---|
| Peek A / 10 | Reserved at the initial deal | Against Ace or 10 |
| Ace peek only | Reserved at the initial deal | Against Ace only |
| ENHC · no hole card | Drawn after player actions | None |
ENHC means European no-hole-card. B has a hole card but no peek against 10, so it is not an ENHC deal. Wizard of Odds lists no peek on 10 and European no-hole-card among the rule variations.
05 / TWO FRESH PRACTICE STATES
Enter the rules before the hand.
- Set up case A.
Use eight decks, S17, any-two double, no surrender and no Cash Out. Select Peek A / 10 and All bets lose. Apply the rules and begin a fresh shoe. The first-round guide covers saving and applying a ruleset, including the reset of the shoe and session statistics.
- Enter 5, dealer 10, then 6.
At DEALER CHECK, the app asks you to Resolve dealer check. For practice case A, choose No blackjack. In a recorded round, use only the result that actually occurred; a pending check is not a no-blackjack result.
- Read the calculated actions.
Select FULL and wait for an EXACT result for this supported hand. Expect DOUBLE at +0.1788 units. The mode selects the calculation; the accuracy label describes the result.
- Start case B as a separate practice state.
Change the hole-card rule to Ace peek only, keep All bets lose, and apply the rules to a fresh shoe. Re-enter the same three cards. There is no dealer-check prompt against 10. The exact result now favours HIT at +0.0321 units.
Quick check: B says DOUBLE. What should you inspect?
Check the settlement rule first: Original bet only (OBO) produces Double in the optional comparison above. Then verify the hole-card setting, fresh shoe, entered ranks and result accuracy. A different answer may be correct for a different state.
Inspect the exact starting state and rules
Start with 416 cards and expose one 5, one 10 and one 6. The unseen composition is 32 Aces; 32 each of 2, 3, 4, 7, 8 and 9; 31 fives; 31 sixes; and 127 ten-value cards. Both main states contain 413 unknown identities, including the reserved hole card, with 412 physical cards still in the shoe. The no-blackjack information restricts the possible hole-card rank without changing those rank counts. No other exposed or burn card is assumed.
Shared rules: S17, 3:2 blackjack, any-two double, DAS, at most two split hands, split aces allowed without resplit, hit or double of split aces; no surrender and no Cash Out. Penetration is 75%; the profile is Extended with floor TC and half-deck estimation. These are ordinary, unsplit hands. A uses Peek A / 10; B uses Ace peek only. Both use All bets lose; the OBO comparison changes only that settlement setting.
FULL returns EXACT finite-composition action values for these supported states. The exact Stand and Double values were also checked by a separate enumeration of the remaining cards and dealer paths; the Hit values were cross-checked using the blackjack and no-blackjack probabilities. Results were calculated on 13 September 2026.
Sources and further reading
The hand, action values and chosen settlements are original Advantage Count teaching examples. External sources support the dealer-check assumptions and rule definitions.