Blackjack Basic Strategy: The Complete Decision Guide

Most casino games don’t reward thinking. Slots pay according to an algorithm you have no influence over. Roulette is pure probability. Baccarat might as well be a coin flip with extra steps.

Blackjack is different. The decisions you make — hit, stand, double, split — actually change your expected results. Not dramatically, and not in a way that flips the house edge in your favour. But the gap between a player who knows basic strategy and one who plays on instinct is mathematically real. Around 1.5 to 3.5 percentage points of house edge, depending on how badly the instinct player guesses.

At a $10 table, over four hours of play, that gap is roughly $40 in expected losses. At $25 per hand, you’re looking at closer to $100. These aren’t huge numbers on their own, but they’re the difference between a reasonable evening out and an expensive one.

This guide covers the complete basic strategy for standard multi-deck blackjack. Three tables — hard hands, soft hands, pairs — and the reasoning behind the decisions that surprise people most.

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Where basic strategy came from

Four US Army engineers — Roger Baldwin, Wilbert Cantey, Herbert Maisel, James McDermott — published a paper in 1956 called “The Optimum Strategy in Blackjack.” They’d spent years doing the calculations by hand. Later researchers ran the same work through computers. Hundreds of millions of simulated hands.

What came out was a decision table. Your hand plus the dealer’s upcard equals one correct play. Not the play that wins this hand. The play that loses the least money if you repeat this exact situation a thousand times.

That framing matters more than people realise. Take hitting 16 against a dealer 10. It feels wrong — you’ll bust a lot. But standing on 16 against a dealer 10 loses even more often, because the dealer completes a strong hand frequently enough that your standing 16 just loses quietly instead. You’re picking the option that bleeds slower.

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The rules that should be automatic

Before the full charts, these are the decisions worth having wired in before you sit down:

Always, no exceptions:

• Split a pair of Aces
• Split a pair of 8s
• Hit soft 17 (Ace + 6) — never stand on it
• Double on hard 11 against any dealer upcard except an Ace

Never, regardless of what feels right:

• Split 10s — you have 20, stand
• Split 5s — treat it as hard 10, double or hit
• Take insurance — it’s a side bet with a 7.4% house edge, completely separate from your main hand
• Stand on soft 17

The insurance thing is worth a moment. When the dealer shows an Ace, the casino offers a side bet paying 2:1 if the dealer has a 10 underneath. It feels protective. In a standard deck, roughly 30% of cards are 10-value. Insurance pays 2:1 but the true odds sit around 2.18:1 against you. It costs money every time. Never take it.

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Hard hands

A hard hand has no Ace, or an Ace that must count as 1 to avoid busting.

Your Hand	Dealer 2	Dealer 3	Dealer 4	Dealer 5	Dealer 6	Dealer 7	Dealer 8	Dealer 9	Dealer 10	Dealer A
8 or less	Hit	Hit	Hit	Hit	Hit	Hit	Hit	Hit	Hit	Hit
9	Hit	Double	Double	Double	Double	Hit	Hit	Hit	Hit	Hit
10	Double	Double	Double	Double	Double	Double	Double	Double	Hit	Hit
11	Double	Double	Double	Double	Double	Double	Double	Double	Double	Hit
12	Hit	Hit	Stand	Stand	Stand	Hit	Hit	Hit	Hit	Hit
13	Stand	Stand	Stand	Stand	Stand	Hit	Hit	Hit	Hit	Hit
14	Stand	Stand	Stand	Stand	Stand	Hit	Hit	Hit	Hit	Hit
15	Stand	Stand	Stand	Stand	Stand	Hit	Hit	Hit	Surrender	Hit
16	Stand	Stand	Stand	Stand	Stand	Hit	Hit	Surrender	Surrender	Surrender
17+	Stand	Stand	Stand	Stand	Stand	Stand	Stand	Stand	Stand	Stand

Two spots in this table trip people up more than any others.

Hard 12 against dealer 2 or 3: hit. Not stand — hit. Players see a low dealer upcard and assume weakness. Dealer 2 and 3 are medium, not weak. The dealer busts far more reliably with 4, 5, or 6 showing. Against 2 and 3, hitting your 12 loses slightly less than standing. Small difference, but it’s there every time you face it.

Hard 16 against dealer 9, 10, Ace: if surrender exists at your table, take it. Give up half your bet and move on. No option here is good. When surrender isn’t available, hit. Standing on 16 against a dealer 10 feels like it’s doing something — it isn’t.

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Soft hands

A soft hand has an Ace counted as 11. The key difference is that you can’t bust by taking one more card — if the next card would push you over 21, the Ace drops to 1. That flexibility changes everything about how these hands should be played.

Your Soft Hand	Dealer 2	Dealer 3	Dealer 4	Dealer 5	Dealer 6	Dealer 7	Dealer 8	Dealer 9	Dealer 10	Dealer A
Soft 13 (A,2)	Hit	Hit	Hit	Double	Double	Hit	Hit	Hit	Hit	Hit
Soft 14 (A,3)	Hit	Hit	Hit	Double	Double	Hit	Hit	Hit	Hit	Hit
Soft 15 (A,4)	Hit	Hit	Double	Double	Double	Hit	Hit	Hit	Hit	Hit
Soft 16 (A,5)	Hit	Hit	Double	Double	Double	Hit	Hit	Hit	Hit	Hit
Soft 17 (A,6)	Hit	Double	Double	Double	Double	Hit	Hit	Hit	Hit	Hit
Soft 18 (A,7)	Stand	Double	Double	Double	Double	Stand	Stand	Hit	Hit	Hit
Soft 19+ (A,8+)	Stand	Stand	Stand	Stand	Stand	Stand	Stand	Stand	Stand	Stand

Soft 18 is where the biggest money gets left on the table, consistently. Players stand. It feels fine — you have 18.

The table says: double against dealer 3 through 6. Stand against 7 and 8. Hit against 9, 10, and Ace.

Against a dealer 9, your 18 loses to 19 and 20 constantly. You can’t bust by taking a card — the Ace drops to 1. So you hit, try to improve, and at minimum you haven’t given up the chance.

Soft 17 is simpler: never stand on it, not once. It’s a bad hand played passively. Hit or double every time.

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Pairs

When both your starting cards match, you can split into two separate hands — each with a new bet equal to your original.

Your Pair	Dealer 2	Dealer 3	Dealer 4	Dealer 5	Dealer 6	Dealer 7	Dealer 8	Dealer 9	Dealer 10	Dealer A
A,A	Split	Split	Split	Split	Split	Split	Split	Split	Split	Split
2,2	Split	Split	Split	Split	Split	Split	Hit	Hit	Hit	Hit
3,3	Split	Split	Split	Split	Split	Split	Hit	Hit	Hit	Hit
4,4	Hit	Hit	Hit	Split	Split	Hit	Hit	Hit	Hit	Hit
5,5	Double	Double	Double	Double	Double	Double	Double	Double	Hit	Hit
6,6	Split	Split	Split	Split	Split	Hit	Hit	Hit	Hit	Hit
7,7	Split	Split	Split	Split	Split	Split	Hit	Hit	Hit	Hit
8,8	Split	Split	Split	Split	Split	Split	Split	Split	Split	Split
9,9	Split	Split	Split	Split	Split	Stand	Split	Split	Stand	Stand
10,10	Stand	Stand	Stand	Stand	Stand	Stand	Stand	Stand	Stand	Stand

Aces: always split, no discussion needed.

8s: always split. You have a 16 — one of the worst hands in the game. Splitting turns it into two hands starting at 8 each. Both are playable. The 16 isn’t.

5s: never split. Two 5s is a hard 10. That’s a strong position for doubling. Splitting creates two weak 5s. Don’t.

10s: you have 20. Stand.

9s are the interesting case. Split against 2-6 and 8-9, stand against 7, 10, and Ace. Against dealer 7 — your combined 18 already beats the dealer’s most likely outcome of 17. Why split a winning hand? Against dealer 8 — you’d rather have two chances at beating 18 than one combined 18 that ties it. Against dealer 10 or Ace — the dealer is strong enough that splitting creates two hands likely to lose instead of one.

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When the rules change strategy

These tables work for standard 4-8 deck blackjack with the dealer standing on soft 17 — the most common conditions online. A few variations shift optimal play:

Dealer hits soft 17 (H17): House edge goes up roughly 0.2%. Double more aggressively against a dealer Ace to partially compensate.

Single deck: A few doubles shift — hitting 8 against dealer 5 or 6 becomes a double. Core soft hand and pair strategy stays largely the same.

No hole card (European rules): Dealer doesn’t take a second card until players have acted. Don’t double or split against dealer 10 or Ace — if the dealer has blackjack, you lose the doubled bet too.

Surrender available: Use it on hard 16 against dealer 9, 10, Ace, and hard 15 against dealer 10. No surrender at your table? Hit those spots instead.

6:5 blackjack payout: Check this before you sit down anywhere. A natural blackjack paying 6:5 instead of 3:2 adds 1.4% to the house edge — more than wiping out everything basic strategy gains. No adjustment fixes it. Leave.

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What basic strategy won’t do

It won’t make you a long-term winner. The math doesn’t work that way. Even with perfect execution, the casino keeps roughly $0.50 per $100 wagered. Over time, you lose.

What it does is make that loss as small as possible. The difference between 0.5% and 3% house edge sounds abstract until you put real stakes behind it.

Card counting is a separate topic — it does shift the edge, under specific conditions, for players willing to put in hundreds of hours of practice. It doesn’t apply to online RNG blackjack, which shuffles between every hand. It requires basic strategy as a foundation. Most people who attempt it don’t execute it accurately enough to matter.

For most players, basic strategy is the whole job. It’s enough.

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Using the chart

Online, keep this guide open in another tab. No restrictions. In a physical casino, printed strategy cards are sold in gift shops and allowed at most tables — the casino’s edge is small enough that they don’t mind.

The goal is to make the decisions automatic. Work through the hard hand table first — start with the clear cases at both ends (8 or less always hits, 17+ always stands) and build toward the complicated middle (12-16 against various dealer upcards). Then soft hands, with particular focus on soft 18. Then pairs.

Playing free demo blackjack with the chart visible speeds up the process considerably. The decisions that feel wrong at first — hitting 12 against dealer 2, splitting 8s against a dealer Ace — become instinctive faster than most people expect.