What Is Blackjack Basic Strategy?
Basic strategy is a mathematically derived set of decisions that tells you the statistically optimal play for every possible combination of your hand and the dealer's upcard. It was developed through computer simulations running millions of hands and has been refined over decades. Following it precisely reduces the house edge to roughly 0.5% or less in a standard game — making blackjack one of the best bets in any casino.
Without basic strategy, the house edge on blackjack can climb to 2–4%, depending on how poorly decisions are made. The difference is significant over any meaningful volume of hands.
The Core Principles
Hard Totals (No Ace, or Ace Counted as 1)
- 8 or less: Always hit.
- 9: Double down if dealer shows 3–6; otherwise hit.
- 10–11: Double down if you have more points than the dealer's upcard; otherwise hit.
- 12–16: Stand if dealer shows 2–6 (bust cards); hit against 7 or higher.
- 17 or more: Always stand.
Soft Totals (Hand Contains an Ace Counted as 11)
- Soft 13–15 (A-2 to A-4): Double if dealer shows 4–6; otherwise hit.
- Soft 16–17 (A-5 to A-6): Double if dealer shows 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: Always stand.
Pairs (Splitting)
- Always split: Aces and 8s.
- Never split: 5s (treat as hard 10) or 10s (you already have 20).
- Split 2s, 3s, 7s: Against dealer 2–7.
- Split 6s: Against dealer 2–6.
- Split 9s: Against dealer 2–6 and 8–9; stand against 7, 10, Ace.
- Split 4s: Only against dealer 5–6 (if doubling after split is allowed).
Why Does the Dealer's Upcard Matter So Much?
The dealer is constrained by strict rules — they must hit until they reach 17 or more. When the dealer shows a "bust card" (2 through 6), they are statistically more likely to exceed 21. In these situations, basic strategy often tells you to stand on mediocre hands and let the dealer bust, rather than risk busting yourself.
When the dealer shows a strong card (7 through Ace), the calculus reverses — you need to improve your hand because the dealer is unlikely to bust.
Rule Variations That Affect the House Edge
| Rule | Effect on House Edge |
|---|---|
| Blackjack pays 3:2 (vs. 6:5) | Reduces edge by ~1.4% |
| Dealer stands on soft 17 | Reduces edge by ~0.2% |
| Double after split allowed | Reduces edge by ~0.1% |
| Re-splitting aces allowed | Reduces edge by ~0.08% |
| More decks (1 vs. 8 deck) | Increases edge by ~0.6% |
How to Learn Basic Strategy
- Use a strategy card: Most casinos allow players to reference a printed basic strategy card at the table. Use it until the decisions become automatic.
- Practice online: Free blackjack simulators give you instant feedback when you deviate from correct play.
- Focus on the hard totals first: They come up most frequently and cover the majority of decisions you'll face.
- Memorize splitting rules: Incorrect splitting decisions are among the costliest mistakes recreational players make.
What Basic Strategy Is NOT
Basic strategy does not guarantee wins or eliminate the house edge entirely. It minimizes the edge so you lose at the slowest possible mathematical rate. It is the essential foundation for anyone serious about blackjack — including card counters, who layer their counting system on top of a flawless basic strategy foundation.