Basic Strategy

Basic strategy is the mathematically proven correct play for every player hand vs. every dealer upcard. Following it gives you the best possible odds against the casino.

Basic strategy is a complete decision table: for every combination of player hand and dealer upcard, it tells you the single play (hit, stand, double, split, surrender) that maximizes expected value over the long run. The chart was derived through computer simulation by Edward Thorp in 1962 and refined by mathematicians and casino-game analysts ever since.

There is one canonical basic strategy chart per rule set. The strategy for a 6-deck S17 game with DAS allowed is slightly different from a 1-deck H17 game without DAS. Most casino blackjack falls into a small number of common rule combinations — basic strategy charts for those are widely published and well-validated.

Without basic strategy, blackjack's house edge balloons to 2–3% or more — the player is guessing at every decision. With perfect basic strategy, the house edge falls to:

• ~0.26% on a 6-deck S17 game with DAS, late surrender, and 3:2 blackjack payouts (the "good" Strip rule set)
• ~0.44% on a more typical 6-deck or 8-deck S17 game with DAS
• ~0.60% on a 6-deck H17 game with DAS
• ~2.00% on a 6-deck H17 game with 6:5 blackjack payouts (avoid)

Across thousands of hands, the difference between guessing and basic strategy compounds into hundreds or thousands of dollars.

• Hard 16 vs. dealer 10: Hit (or surrender if available). Standing is the most common mistake on this hand.
• Hard 11 vs. anything except dealer Ace: Double down. The most profitable play in basic strategy.
• Pair of 8s: Always split, regardless of dealer upcard. Two hands of 8 each are better than one hand of 16.
• Soft 18 vs. dealer 9: Hit. Counterintuitive — an 18 feels strong, but the math says draw against 9, 10, A.
• Pair of 5s: Never split. Treat as a hard 10 and double or hit normally.

Blackjack Navigator Pro's coaching system shows the basic strategy correct play for every decision in three modes: Always (hint before every action), Think First (decide first, then feedback), and Mistakes Only (quiet unless you slip). The Strategy Explorer lets you look up the correct play for any hand vs. any dealer upcard outside of gameplay.

• House Edge — the casino's mathematical advantage
• Expected Value — the math underlying every basic strategy decision
• Soft Hand — basic strategy for hands with an Ace counted as 11
• Hard Hand — basic strategy for hands without a flexible Ace
• Full glossary