What Is Blackjack Basic Strategy?
Blackjack is unique among casino games because your decisions directly affect the outcome. Basic strategy is a set of mathematically derived rules that tells you the statistically best action — hit, stand, double down, or split — for every possible combination of your hand and the dealer's upcard.
Playing perfect basic strategy reduces the house edge to approximately 0.5% in standard multi-deck games — far lower than almost any other casino game.
The Core Principles
Basic strategy is built on one simple idea: the dealer must hit until reaching 17 or above, and the dealer has a roughly 28% chance of busting depending on their upcard. Your decisions should exploit this.
When to Stand
- Stand on hard 17 or above — always.
- Stand on hard 13–16 when the dealer shows 2–6 (dealer bust territory).
- Stand on soft 19 or above.
When to Hit
- Hit on hard 8 or less — you cannot bust.
- Hit on hard 12–16 when the dealer shows 7 or higher.
- Hit on soft 17 or below (Ace + 6 or less).
When to Double Down
- Double on hard 11 against any dealer upcard except Ace.
- Double on hard 10 when dealer shows 2–9.
- Double on hard 9 when dealer shows 3–6.
When to Split Pairs
- Always split Aces and 8s.
- Never split 10s or 5s.
- Split 2s and 3s against dealer 2–7.
- Split 6s against dealer 2–6.
- Split 9s against dealer 2–6 and 8–9.
Understanding Soft vs. Hard Hands
A hard hand is any hand without an Ace, or where the Ace counts as 1. A soft hand includes an Ace counted as 11. Soft hands are more flexible because you cannot bust by taking one card.
| Hand Type | Example | Key Point |
|---|---|---|
| Hard 16 | 10 + 6 | Worst hand — hit vs. 7+, stand vs. 2–6 |
| Soft 18 | Ace + 7 | Hit vs. 9, 10, Ace; double vs. 3–6 |
| Hard 11 | 7 + 4 | Strong double down candidate |
Common Mistakes to Avoid
- Never take insurance. Insurance is a side bet with a house edge of around 7% — it is one of the worst bets in the casino.
- Don't "play it safe" with 12 against a 2. Basic strategy says hit — the math supports it even though it feels risky.
- Don't split 10s — a 20 is a winning hand; don't break it up for greed.
- Ignore hunches about the next card. Each deal is independent. There is no "due" card.
Rule Variations That Affect Strategy
Different blackjack variants have different rules that shift the house edge slightly:
- Dealer hits soft 17 (H17) — slightly worse for the player vs. stand on soft 17 (S17).
- Double after split allowed — reduces house edge.
- Number of decks — single-deck games theoretically favour the player more, but casinos compensate with worse rules.
Practise Before You Play
Basic strategy charts are freely available and legal to use. Most online casinos allow you to play in demo mode — use this to practise until the decisions become second nature. Print a strategy card or keep one open in another tab when you start playing for real money.