Blackjack Basic Strategy Calculator
Enter your hand and the dealer's upcard to get the statistically optimal Basic Strategy action based on standard multi-deck (4–8 deck) casino rules.
Your optimal action will appear here.
Strategy Tables
This calculator implements the multi-deck (4–8 deck) Basic Strategy for standard casino rules: dealer stands on soft 17, double after split (DAS) allowed, late surrender available. Three decision tables are used:
- Hard Totals (5–20): Decisions based solely on your numeric total and dealer upcard. No aces counted as 11.
- Soft Hands (Soft 13–20): One ace counted as 11 plus one other card (2–9). Doubling opportunities arise on soft 13–18 against weak dealer upcards.
- Pairs: Whether to split depends on the pair rank and dealer upcard. Always split Aces and 8s; never split 10s or 5s.
Action codes: H = Hit · S = Stand · Dh = Double (else Hit) · Ds = Double (else Stand) · SP = Split · Rh = Surrender (else Hit) · Rs = Surrender (else Stand)
Basic Strategy reduces the house edge to approximately 0.4%–0.6% in standard multi-deck games.
Assumptions & References
- Multi-deck shoe (4–8 decks) — the most common casino configuration.
- Dealer stands on soft 17 (S17 rules).
- Double After Split (DAS) is permitted.
- Late Surrender is available (if not, follow the fallback action shown).
- Re-splitting aces is not assumed; split aces receive one card each.
- Strategy source: Wizard of Odds multi-deck basic strategy charts (wizardofodds.com).
- Reference: Beat the Dealer by Edward O. Thorp (1962) — foundational work on blackjack strategy.
- Reference: Griffin, P. (1999). The Theory of Blackjack. Huntington Press.
- This calculator provides the statistically optimal action to minimise the house edge over the long run. It does not account for card counting or side bets.