This trainer implements **basic strategy** for the selected rules. For practice/education only.
Pairs: AA, 8-8 = Split; 10-10 = Stand; 9-9 = Split vs 2–6 & 8–9 (Stand vs 7,10,A); 7-7 = Split vs 2–7; 6-6 = Split vs 2–6 (NDAS: 3–6); 5-5 = treat as hard 10; 4-4 = Split vs 5–6; 2-2/3-3 = Split vs 2–7 (NDAS: 4–7).
Soft: A,9 = Stand (Double vs 6 if rules/allowed). A,8 = Stand; (H17: Double vs 6 if allowed). A,7 = Double vs 3–6; Stand vs 2,7,8; Hit vs 9,10,A (H17: Double vs 2–6).
Hard: 17+ Stand; 16 Stand vs 2–6 else Hit (LS: 16 vs 9,A); 15 Stand vs 2–6 else Hit (LS: 15 vs 10); 13–14 Stand vs 2–6 else Hit; 12 Stand vs 4–6 else Hit; 11 Double vs 2–10 (H17: also vs A) else Hit; 10 Double vs 2–9 else Hit; 9 Double vs 3–6 else Hit; 8- Hit.
Late Surrender (LS): First two cards only: 16 vs 9/A; 15 vs 10.
Running Count (RC): Hi‑Lo (+1 for 2–6, 0 for 7–9, −1 for 10–A) using only visible cards.
True Count (TC): RC ÷ decks remaining (unknown cards / 52). Higher TC generally favors the player.
Deck Composition (unknown): percentages among all unknown cards (shoe + any face‑down cards): Tens (10/J/Q/K), Aces, High (Tens + Aces), Low (2–6), Neutral (7–9).
Next‑hand Blackjack %: Approximation 2×(A/N)×(T/(N−1)).