Blackjack Basic Strategy Calculator

Casino

By | February 24, 2026 | Leave a Comment | 7 minutes of reading
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Blackjack is unique among casino games because it is solvable. There is a mathematically “perfect” move for every single combination of cards — this is called Basic Strategy.

Playing by “feel” gives the casino a 2-4% edge. Playing by Basic Strategy reduces that edge to under 0.5%. Select your hand and the dealer’s upcard below to see the optimal move instantly.


Blackjack Strategy
HIT

How to Use the Strategy Advisor

  1. Select Your Hand: Choose your current total from the dropdown.
    • Hard Totals: Hands without an Ace, or where the Ace counts as 1 (e.g., 10 + 6 = Hard 16).
    • Soft Totals: Hands with an Ace counted as 11 (e.g., Ace + 6 = Soft 17).
    • Pairs: Two cards of the same rank (e.g., 8-8 or A-A).
  2. Select the Dealer’s Up Card.
  3. Get the Action:
    • HIT — Take another card.
    • STAND — Hold your current total.
    • DOUBLE — Double your bet, receive exactly one card.
    • SPLIT — Split the pair into two separate hands.
Want to know WHY each play is correct? The Decision EV Calculator shows the exact expected value for each option, so you can see exactly how much each mistake costs you per dollar bet.

Quick Reference: Hard Totals

Hard hands (no Ace counted as 11) are the most common decisions. The core logic is simple: stand on strong hands against weak dealer cards, hit when the dealer is strong.

Your Hand Dealer 2-3 Dealer 4-6 Dealer 7-9 Dealer 10-A
17+ Stand Stand Stand Stand
13-16 Stand Stand Hit Hit
12 Hit Stand Hit Hit
11 Double Double Double Double*
10 Double Double Double Hit
9 Hit Double Hit Hit
5-8 Hit Hit Hit Hit

*Double 11 vs Ace only under H17 rules. Under S17, hit instead.

Quick Reference: Soft Totals & Pairs

Soft hands contain an Ace counted as 11, giving you flexibility — you can always hit without risk of busting. The strategy is more aggressive: double more often against dealer weak cards (3-6), and hit soft 18 against dealer 9, 10, or Ace.

Soft Hand Dealer 2-3 Dealer 4-6 Dealer 7-8 Dealer 9-A
A-9, A-10 Stand Stand Stand Stand
A-8 (19) Stand Stand† Stand Stand
A-7 (18) Stand Double Stand Hit
A-6 (17) Hit Double Hit Hit
A-4, A-5 Hit Double Hit Hit
A-2, A-3 Hit Double‡ Hit Hit

†Double A-8 vs 6 under H17 rules only. ‡A-2 and A-3 double vs 5-6 only (not vs 4).

Pairs follow two absolute rules — always split Aces and 8s, never split 10s and 5s — plus a handful of conditional splits:

Pair Action
A-A Always Split
10-10 Always Stand (20 is too strong to break up)
9-9 Split vs 2-6 and 8-9. Stand vs 7 (18 beats 17), 10, Ace
8-8 Always Split (16 is the worst hand in the game)
7-7 Split vs 2-7. Hit vs 8+
6-6 Split vs 2-6 (DAS) or 3-6 (no DAS). Hit vs 7+
5-5 Never Split — treat as Hard 10 (double vs 2-9, hit vs 10-A)
4-4 Split vs 5-6 if DAS. Otherwise hit (treat as Hard 8)
3-3, 2-2 Split vs 2-7 (DAS) or 4-7 (no DAS). Hit vs 8+

The Most Misplayed Hands

Three hands cause more mistakes (and more lost money) than any others:

Hard 16 vs Dealer 7: Most players stand because they’re afraid to bust. The calculator says Hit. Standing against a dealer showing 7 loses more often because the dealer is likely to make 17 and beat you automatically. Hitting is risky (you bust ~62% of the time), but when you don’t bust, you can actually win. Overall, hitting loses less. To see exactly how much less, check the Decision EV Calculator.

Soft 18 (A-7) vs Dealer 9: Eighteen feels like a strong hand. Against a 9, it isn’t — the dealer will make 19 or better roughly 54% of the time. Hitting cannot bust you (the Ace shifts from 11 to 1), so the downside is capped. This is the play that separates basic strategy players from casual ones.

Pair of 8s vs Dealer 10: Nobody wants to put double the money on the table against a face card. But keeping 16 is worse than starting two hands from 8. This is called a “defensive split” — you split not to win, but to lose less. The EV Calculator shows the exact numbers.

Beyond Basic Strategy

Basic Strategy reduces the house edge to roughly 0.4-0.6%, but it does not eliminate it. The casino still has a mathematical advantage. To actually flip the edge in your favor, you need to progress through the following steps:

  1. Know the rules. The House Edge Calculator shows exactly how each rule (H17, 6:5, no DAS) affects the casino’s advantage. Choose tables with the lowest edge before you sit down.
  2. Learn to count. The Card Counting Guide teaches the Hi-Lo system — tracking the ratio of high to low cards left in the shoe.
  3. Convert running count to true count. The True Count Calculator handles the math.
  4. Adjust your plays. At certain true counts, basic strategy changes. The Deviations Calculator lists the Illustrious 18 — the 18 most valuable index plays.
  5. Size your bets and bankroll. The Bankroll Calculator determines how much you need to survive the variance of counting.

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Frequently Asked Questions (FAQ)

What is basic strategy in blackjack?

Basic strategy is a set of mathematically optimal decisions for every possible blackjack hand, derived from computer simulations of billions of rounds. For every combination of player hand and dealer upcard, there is exactly one play that loses the least money on average. Following basic strategy perfectly reduces the house edge to approximately 0.4-0.6% depending on the table rules.

Does basic strategy guarantee I will win?

No. Basic strategy minimizes the house edge but does not eliminate it. Over the long run, the casino still has an advantage of roughly 0.5%. However, basic strategy dramatically reduces losses compared to playing by intuition (which typically gives the casino a 2-4% edge). To actually gain a positive expectation, you need to combine basic strategy with card counting.

Why should I always split Aces and Eights?

Aces: A single Ace starts at 11, giving you two chances to make 21 or a strong hand. Keeping two Aces as a soft 12 wastes their power. Eights: Two 8s make 16 — the worst hand in blackjack. Splitting gives you two hands starting from 8, where catching a 10 makes 18. In both cases, splitting converts a terrible hand into two with much better expected outcomes. See the exact EV numbers in the Decision EV Calculator.

Should I take insurance in blackjack?

Almost never. Insurance is a side bet with a house edge of approximately 7.5% in a 6-deck game — one of the worst bets on the table. The only time insurance becomes mathematically correct is when you are counting cards and the true count is +3 or higher.

Does the number of decks affect basic strategy?

Only on a few borderline hands. The core strategy is identical for any number of decks. The differences are in edge cases like doubling soft 13 vs 5 (hit in single deck, double in 6+ decks). For practical purposes, learning one chart covers virtually all games. To see how deck count affects the overall house edge, use the House Edge Calculator.

What is the difference between basic strategy and card counting?

Basic strategy assumes no information about remaining cards. Card counting tracks the ratio of high to low cards and adjusts bet sizing and certain strategic decisions. Basic strategy is the foundation that reduces the edge to ~0.5%; card counting is the advancement that can flip it to +0.5-1.5% in the player’s favor. Start with the Card Counting Guide once you have basic strategy memorized.

How does H17 vs S17 change basic strategy?

When the dealer hits soft 17 (H17), the house edge increases by about 0.2%. A few decisions change: double 11 vs Ace, double soft 19 vs 6, and surrender 15 and 17 vs Ace. The rest of the chart stays the same. Check the Blackjack EV Guide for a full rule impact analysis.

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