What Is Basic Strategy?
Blackjack is the only common casino game where your decisions directly impact the house edge. Play randomly, and the house might hold a 2–4% edge over you. Play using basic strategy — a mathematically derived set of decisions — and you can reduce that edge to less than 0.5% in many game variants.
Basic strategy tells you the statistically optimal play for every possible combination of your hand versus the dealer's upcard. It doesn't guarantee wins — no strategy can — but it guarantees you're making the best possible decision in the long run.
The Core Rules of Basic Strategy
Always / Never Rules (Non-Negotiable)
- Always split Aces and 8s. Two Aces gives you two chances at 21. Two 8s turns a terrible 16 into two playable hands.
- Never split 10s or 5s. A 20 is already a great hand. Two 5s are better doubled against weak dealer cards.
- Never take insurance. It's a side bet with poor odds that benefits the casino significantly.
Hard Hands (No Ace or Ace Counted as 1)
| Your Hand | Dealer Shows 2–6 | Dealer Shows 7–Ace |
|---|---|---|
| 8 or less | Hit | Hit |
| 9 | Double | Hit |
| 10–11 | Double | Double (hit if dealer shows Ace) |
| 12–16 | Stand | Hit |
| 17+ | Stand | Stand |
Soft Hands (Ace Counted as 11)
Soft hands are more flexible because you can't bust on one more card.
- Soft 13–15 (A-2 to A-4): Double against dealer 4–6, otherwise Hit
- Soft 16–17 (A-5, A-6): Double against dealer 3–6, otherwise Hit
- Soft 18 (A-7): Stand against 2, 7, 8; Double against 3–6; Hit against 9, 10, Ace
- Soft 19–20 (A-8, A-9): Always Stand
Understanding the Dealer's Bust Probability
A key insight behind basic strategy is that the dealer must follow fixed rules — typically hitting until reaching 17 or higher. When the dealer shows a "bust card" (2–6), they have a higher probability of busting. This is why basic strategy tells you to stand on weaker hands and double down more aggressively when the dealer is vulnerable.
When the dealer shows a strong card (7 through Ace), they're more likely to make a solid hand, so you must take more risks to improve your own total.
Doubling Down: When to Double Your Bet
Doubling down lets you double your initial bet in exchange for receiving exactly one more card. It's one of the most powerful tools in blackjack and is frequently underused by beginners.
- Double on 11 against almost any dealer upcard
- Double on 10 against dealer 2–9
- Double on 9 against dealer 3–6
- Double soft hands aggressively when the dealer shows 3–6
Surrender: The Underrated Option
Many casinos offer late surrender, which lets you forfeit half your bet instead of playing out a losing hand. Use it on:
- Hard 16 against dealer 9, 10, or Ace
- Hard 15 against dealer 10
Surrendering saves money over the long run by cutting losses on the statistically worst situations.
Common Mistakes to Avoid
- Mimicking the dealer (always hitting until 17) — this ignores doubling and splitting opportunities
- Standing on soft 17 — you can't bust, and improving to 18+ is possible
- Taking insurance — the odds simply don't justify it
- Playing hunches — basic strategy is built on millions of simulated hands; intuition doesn't beat math
Practice Before You Play
Most online casinos offer free play blackjack. Use it to drill basic strategy until decisions become automatic. You can also find free basic strategy cards — many casinos allow you to reference them at the table. The house would rather you use a strategy card than play blindly, because they know their edge remains even against optimal play.
Master the basics first. Once basic strategy is second nature, you'll have the foundation to explore more advanced concepts like shuffle tracking or card counting.