Blackjack strategy: basic strategy explained, with the full chart

Basic strategy is a fixed set of decisions, one for every combination of your hand and the dealer's up-card, that gives the best long-run result under a stated set of rules. Follow it and the house edge in a typical UK six-deck game drops to about 0.5%. Play by instinct and it is usually 2% or more. This page explains the strategy, shows the full chart, works through the hands people get wrong, and sets out what changes in UK games where the dealer takes no hole card.

If you only want the reference, go straight to the blackjack strategy chart or check a specific hand in the blackjack strategy calculator. If you are new to the game, read how to play blackjack first.

What basic strategy is

Every blackjack decision is a comparison. Hitting hard 16 against a dealer 10 loses money on average; standing loses more. Basic strategy is the table of those comparisons, resolved in the player's favour for each hand and up-card.

The first version was published in 1956 by four US Army mathematicians (Baldwin, Cantey, Maisel and McDermott), refined by Edward Thorp in 1962, and has since been confirmed by computer simulation of billions of hands. The decisions on this page come from that work, calculated for the rules stated above each chart.

Three things basic strategy does not do:

• It does not predict the next card. It plays the odds across every card that could come.
• It does not win every hand. Even played perfectly, you lose slightly more hands than you win (about 49% to 42%, with 9% pushed).
• It does not make blackjack profitable. It makes the loss as small as the rules allow. Only card counting can go further, and only under conditions most games do not offer.

The chart

Rules assumed: four to eight decks, dealer stands on soft 17, double on any two cards, double after split allowed, late surrender available, dealer checks for blackjack. This is the most common set of rules in online RNG games and in most published charts. For UK live and land-based games, which deal no hole card, see the UK section below.

Key: H hit · S stand · D double (hit if not allowed) · Ds double (stand if not allowed) · P split · R surrender (hit if not allowed)

Hard totals

Soft totals

Pairs

Charts for dealer hits soft 17, no double after split, single deck, double deck and UK no hole card rules, plus printable versions, are on the blackjack strategy charts.

How to read the chart in four steps

1. Look at the dealer's up-card first. It sets the column. Think of 2 to 6 as weak (the dealer busts 35% to 42% of the time) and 7 to ace as strong (busts 17% to 26% of the time).
2. Classify your hand. A pair of identical values is a pair. A hand with an ace that can count as 11 without busting is soft. Everything else is hard. Check in that order, because A,A is a pair before it is soft 12, and A,7 is soft 18 before it is "18".
3. Find the row in the right table and read across to the dealer's column.
4. Apply the letter, with the fallback if the table does not allow the action (no doubling on three cards, say).

Worked example: you hold A,7 and the dealer shows 9. Dealer column 9. Your hand is not a pair; it contains an ace counting as 11, so it is soft 18. Soft totals table, row A,7, column 9: H. Hit. Most people stand on 18 here and lose more over time than those who hit, because 18 is a losing total against a 9 and a hit cannot bust a soft hand.

Hard totals

Three rules of thumb cover most hard hands:

• 8 or less: always hit. You cannot bust and a low total is worth nothing.
• 17 or more: always stand. The bust risk on a hit is 69% or higher.
• 12 to 16: the awkward zone. Stand against a weak dealer card (2 to 6) because the dealer is likely to bust; hit against a strong card (7 to ace) because your total will not win if the dealer stands.

The decisions that catch people out are the exceptions to that pattern, and the doubling windows.

Soft totals

A soft hand holds an ace counted as 11. One more card cannot bust it, because the ace drops to 1 if needed. That makes soft hands flexible: you can hit them freely, and double them against weak dealer cards even when the total looks respectable.

Soft 17 is never a standing hand. A hard 17 stands because hitting busts 69% of the time; a soft 17 cannot bust on one card and 17 itself wins only when the dealer busts. Soft 18 is the most misplayed hand in blackjack: it stands only against 7 and 8, where 18 is already a winning total, and it hits against 9, 10 and ace, where 18 loses more often than it wins.

Pairs

Splitting turns one hand into two, each starting with one of the pair, for a second stake. The question is always whether two new hands are worth more than the one you have.

Four fixed rules:

• Always split aces. Two hands starting on 11 are far better than one soft 12. Most games deal only one card to each split ace.
• Always split 8s. Hard 16 is the worst total in the game. Two hands starting on 8 lose less, even against a 10 or an ace in a hole-card game.
• Never split 10s. 20 is the second-best hand you can hold. Splitting it to chase two 20s wins less than keeping it.
• Never split 5s. Two hands starting on 5 are poor. Hard 10 is a doubling hand.

The remaining pairs depend on the dealer's card:

The 9,9 row is the one worth memorising. Against a 7 you stand, because 18 beats the dealer's likely 17. Against 8 and 9 you split, because 18 is no longer good enough and two hands starting on 9 do better. Against 10 and ace you stand, because splitting into a strong card loses more.

The 2,2, 3,3, 4,4 and 6,6 splits assume you can double after splitting. If the table does not allow it, 4,4 is never split, and 2,2, 3,3 and 6,6 are split against one fewer dealer card each.

Doubling, surrender and insurance

Doubling

Doubling puts a second stake on the hand in exchange for exactly one more card. It is right when your total is likely to finish strong and the dealer is likely to finish weak. The windows are narrow: hard 9 against 3 to 6, hard 10 against 2 to 9, hard 11 against 2 to 10, and the soft doubles in the table above. Outside those windows the one-card restriction costs more than the extra stake gains.

Surrender

Late surrender lets you give up the hand after the dealer checks for blackjack and get half your stake back. It is right only when the hand loses more than half its stake on average: hard 16 against 9, 10 and ace, and hard 15 against 10. Under dealer-hits-soft-17 rules, add 15 against ace and 8,8 against ace. Surrender is common in online RNG games and rare in UK live and land-based games.

Insurance

Insurance is a side bet, offered when the dealer shows an ace, that the hole card is a 10. It pays 2 to 1. In a six-deck game the true odds against a ten in the hole are roughly 2.2 to 1, so the bet carries a house edge of around 7%. Basic strategy never takes it, including "even money" on your own blackjack, which is the same bet by another name. The only time insurance is correct is when a card count shows an excess of tens remaining, which is advanced strategy.

UK rules: what changes with no hole card

Most UK land-based casinos and UK live dealer tables deal the dealer one card only and do not check for blackjack until every player has finished. If the dealer then turns over a blackjack, you lose every stake on the table, including any double or split. That changes four doubling or splitting decisions in the chart.

Everything else is unchanged. UK games also typically stand on soft 17, allow doubling on any two cards and after splits, allow splitting to three hands, and do not offer surrender. The full UK chart, with provider-by-provider rules for live tables, is on the UK blackjack strategy guide. The blackjack strategy calculator has a UK rule profile.

What basic strategy does to the house edge

The house edge is a long-run average, not a prediction. Over 100 hands at £10 the expected loss on UK rules is £5, but a swing of £100 either way is ordinary. Over 100,000 hands the average asserts itself. See blackjack odds and house edge for the full figures.

Rule variations and what they cost

The chart above is correct for the rules it states. Other rules change both the edge and, in a few cells, the right play.

Single and double deck games have their own pages: single deck blackjack strategy and strategy by number of decks.

Common mistakes

• Standing on 12 against a 2 or 3. It feels safe. It loses more than hitting.
• Taking insurance or even money. A 7% house edge side bet dressed up as protection.
• Standing on soft 18 against a 9, 10 or ace. 18 is not a good total against those cards, and a soft hand cannot bust on one card.
• Not doubling soft hands. A,6 against a 5 is a double, not a hit.
• Splitting 10s against a 6. Two hands that each average less than the 20 you gave up.
• Hitting 16 against a 7 "because the dealer has a weak card". 7 is not weak. The dealer busts 26% of the time from it. 16 still hits here, and so does 15, 14 and 13.
• Changing bet size to chase a result. No staking pattern changes the expected loss; see blackjack betting strategy.

Basic, perfect and advanced strategy

Basic strategy decides by your total and the dealer's card. It is what this page shows.

Perfect strategy (composition-dependent) also looks at which cards make up your total. Hard 16 made of 10-6 and hard 16 made of 4-5-7 are played slightly differently in some games. The gain over basic strategy is tiny in six-deck games, roughly 0.01% to 0.04%. Details on the perfect blackjack strategy page.

Advanced strategy changes decisions and bet sizes according to a card count. It is the only approach that can produce a player edge, and it works only in shoe games with deep penetration, which rules out most online play. See advanced blackjack strategy and card counting.

How to learn it

Learn in this order: hard totals, then soft totals, then pairs. Each table is small once you see the pattern (weak dealer card: stand or double; strong dealer card: hit). Drill one table until you can play it without looking, then add the next. The blackjack basic strategy trainer deals random hands, scores each decision and shows which category you are weak on. A fuller learning method is on how to learn basic strategy.

Practise with the chart in front of you, including online, where there is nothing to stop you. It takes most people a few hours of drilling to reach 95% accuracy on hard totals and a week or two of occasional practice to be reliable across all three tables.

Frequently asked questions

Does basic strategy work in online blackjack?

Yes, for the hit, stand, double and split decisions. Online RNG games shuffle every hand, which makes card counting pointless, but basic strategy does not depend on previous cards. Check the game's rules (decks, soft 17, hole card) and use the matching chart. See online blackjack strategy.

Is it legal to use a strategy chart in a UK casino?

Yes. A strategy card is a reference, not a device, and UK casinos allow them at the table. Online, nothing stops you keeping the chart open on another screen. The only courtesy is not to slow the table down.

How much does basic strategy improve my chances?

It cuts the house edge from around 2% or more for casual play to about 0.5% under UK rules. Per £1,000 wagered, that is an expected loss of about £5 instead of £20 or more. It does not turn blackjack into a winning game.

Should I always follow the chart, even when it feels wrong?

Yes. The chart is right on average for every cell, and "feels wrong" usually means one of the hands in the mistakes list above. The only legitimate reasons to deviate are a different rule set (use the matching chart) or a card count (see advanced strategy).

Is there a simple version of basic strategy?

A rough version: hit 8 or less; stand on hard 17 or more; with hard 12 to 16, stand against 2 to 6 and hit against 7 to ace (except hit 12 against 2 and 3); double 10 and 11 against anything lower; always split aces and 8s; never split 10s or 5s; never take insurance. That gets within about 0.3% of the full chart. The full chart is not much harder to learn and the blackjack strategy trainer makes the difference quick to close.

Does the number of decks change basic strategy?

Slightly. Single and double deck games widen a few doubling and splitting decisions. The chart on this page is correct for four to eight decks, which covers nearly every UK game. Single deck has its own page.

What is the best hand in blackjack?

A natural blackjack (an ace and a ten-value card as your first two cards), which pays 3 to 2 in a properly paid game. After that, 20. The probability of being dealt a natural is about 4.75% in a six-deck game.

Why is 16 against a 10 a hit when I bust most of the time?

Because standing is worse. Standing on 16 wins only when the dealer busts, which happens 23% of the time from a 10. Hitting busts 62% of the time but wins or pushes often enough when it does not that it loses less overall. Surrender, where offered, is better than either.

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