Basic strategy: play the dealer’s card, not your total.
Basic strategy is the correct play for every hand you can be dealt against every card the dealer can show. It is not a hunch and not a system — it is a solved answer, and it is the difference between a game that costs about half a percent and one that costs five or six. The rules of thumb take an evening. The whole chart takes about a week.
What basic strategy actually is.
There are ten cards the dealer can show and thirty-four two-card hands you can hold — sixteen hard totals, eight soft totals, ten pairs. That is 340 situations, and basic strategy is simply the best play in each one.
“Best” has a precise meaning. For any situation, take every option you have — stand, hit, double, split, surrender where offered — and play each one out against every card the dealer could draw, weighting each outcome by how often it happens. One option returns more than the others over the long run. That option is basic strategy for that hand. Do it 340 times and you have the chart.
Nobody worked this out at a table. It was computed, first by hand in the 1950s and then exhaustively by machine, and it has not changed since because the arithmetic has not changed. Our strategy calculator does the same computation in your browser every time you change a control, which is why it can answer for rule sets no printed chart covers.
One consequence people miss: because the answer depends on the rules, there is no single basic strategy. Whether the dealer hits soft 17, whether you may double after a split, how many decks are in the shoe — each moves a handful of cells. The chart on the back of a casino gift-shop card is right for one game and slightly wrong for most others.
Counting tracks which cards have already left the shoe and changes your bets and plays as the count moves. Basic strategy assumes nothing about what has been dealt. Every counting system is built on top of basic strategy, not instead of it.
It says nothing about how much to bet. Martingale, Paroli and the rest change the size of your swings and never the expectation; basic strategy changes the expectation and says nothing about the swings.
Played perfectly, a standard six-deck game still costs about half a percent. That is the floor, and no chart makes it positive. What basic strategy does is stop you donating the other five points that guessing costs.
What it is worth.
Here are the two ways beginners most often play, and basic strategy, each priced against a six-deck game where the dealer stands on soft 17 — every possible opening deal played out under that policy and weighted by how often it comes up.
The comparison needs JavaScript, because it is solved here rather than stored. The results: playing basic strategy costs about 0.46% of every bet. Mimicking the dealer — hit to 17, stand on 17 or more, never double or split — costs about 5.7%. Never busting — stand on any hard 12 or more, never double or split — costs about 6%. At $25 a hand and a hundred hands an hour, that is roughly $11 an hour against $140 and $150.
Why the gap is so large
Two things are doing the damage in the naive rows, and neither is the one people expect. The first is never doubling: on a hard 10 or 11 against a weak dealer you are a strong favourite, and doubling puts twice as much money on a hand you are winning. Give that up and you have thrown away more than a full percent on its own. The second is never splitting — aces and eights above all. Two hands of A,x are far better than one soft 12; two hands starting from 8 are far better than one hard 16.
The famous close calls — hit or stand on 16 against a ten, hit or stand on 12 against a 4 — are worth almost nothing by comparison. The section below prices them.
The half-percent figure moves with the rules of the table. The house edge calculator prices any rule set and shows which rule is costing you most.
How every decision gets made.
Every cell in the chart came from asking the same questions in the same order. Learn the order and most of the chart stops being a table to memorise and becomes a thing you can reconstruct.
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Look at the dealer’s card before your own
A 2 through 6 busts between 35% and 42% of the time; a 7 through ace, a quarter of the time or less. That single split decides more than anything in your hand: against a weak card you stand on totals you would otherwise hate and double or split aggressively, because the dealer is likely to break. Against a strong card you have to make a hand yourself.
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Is it a pair? Decide whether to split
Splitting is the first question because it changes what hand you are holding. Aces and eights, always. Tens and fives, never — a 20 is a made hand and a 10 is a doubling hand. The other pairs split against a weak dealer and play as a hard total against a strong one.
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Two cards? Decide whether to double
Doubling is next because it is only allowed on your first two cards. Hard 11 against anything but an ace, hard 10 against anything but a ten or ace, hard 9 against 3 through 6. Soft 13 through 18 against a 5 or 6. If the answer is no, you are down to the last question.
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Hit or stand
Hard 17 or more: stand. Hard 12 through 16: stand against 2 through 6, hit against 7 through ace — with the one exception that hard 12 hits against a 2 or 3. Hard 11 or less: hit. Soft 18: stand against 2, 7 and 8, hit against 9, 10 and ace. Soft 17 or less: hit. Soft 19 or more: stand.
The hard-total rules in step four cover every hard hand at a standard table in seven lines. Soft hands are where beginners go wrong most often, because the same total is not the same hand — the soft vs hard hands guide takes those apart. If the dealer’s bust rates are new to you, they are on the rules page, solved for all ten upcards.
The decisions that cost the most.
Fourteen situations players get wrong, each solved for the standard six-deck game: the right play and what it returns, the usual mistake and what that returns, and the gap between them per bet. Sorted by the gap.
The table needs JavaScript, because it is solved here rather than stored. The headline: splitting a pair of fives against a 6 instead of doubling costs about 50% of a bet; hitting a pair of aces against a ten instead of splitting, about 25%; standing on soft 17 against a 6 instead of doubling, about 25%. Hitting hard 16 against a ten instead of standing — the decision people agonise over most — is worth about 0.7%.
What the table is telling you
The decisions people argue about at the table are the cheap ones. Sixteen against a ten is a genuinely close call — both plays lose badly, and the right one loses less by well under a percent of a bet. Twelve against a four is closer still. If you get those wrong occasionally it barely shows up.
The expensive mistakes are the ones nobody argues about because nobody notices making them: playing a pair of fives as a pair instead of as a ten, playing a pair of aces as a soft 12, standing on a soft 17 because seventeen sounds fine, standing on a soft 18 against a nine because eighteen sounds better. None of those feel like decisions. All of them are worth ten to fifty times more than the famous one.
Returns are per bet, on average over many identical hands. A negative number is normal in blackjack — most hands are about losing less, which is exactly why the size of the gap matters more than whether the right play is positive.
How to actually learn it.
In this order, because each layer is smaller than the last and the first one is most of the value.
Seven lines cover every hard hand: hit 8 or less; double 9 against 3–6; double 10 against 2–9; double 11 against 2–10; stand on 12 against 4–6; stand on 13–16 against 2–6; stand on 17 or more. Everything else, hit. That is most of the hands you will see.
Never stand on soft 17 or below. Double soft 13–18 against a 5 or 6, soft 15–18 against a 4, soft 17–18 against a 3. Soft 18 stands against 2, 7, 8 and hits against 9, 10, ace. Soft 19 and 20 stand. The soft vs hard hands guide explains why.
Always split aces and eights. Never split tens or fives — play fives as a ten. Nines split against everything except 7, 10 and ace. Twos, threes and sevens split against 2–7; sixes against 2–6; fours only against 5 and 6. The pair splitting guide has each one priced.
In the meantime
The fastest way to make any of this stick is to be dealt hands and told when you are wrong. The basic strategy trainer does exactly that: it deals, you pick the play, the solver grades it and tells you what the mistake would have cost, and it keeps the hands you got wrong so you can drill just those.
You do not need the chart memorised to play correctly tonight. The strategy calculator solves any hand for the exact rules of the table you are at, and it works the hand out rather than looking it up, so it stays right on rule sets no printed chart covers. When you are ready to memorise, the chart page lays out the hard, soft and pair grids side by side.
The rules move the cells
Everything above assumes six decks, dealer stands on soft 17, double on any two cards, double after split. Change a rule and a few cells change with it: where the dealer hits soft 17, hard 11 doubles against an ace and soft 18 doubles against a 2. Where doubling is restricted to 9–11, every soft double becomes a hit. Fewer decks make a handful of marginal doubles correct. None of it changes the shape of the chart; all of it changes a cell or two. The house edge calculator prices each rule for the table in front of you.
Five things. The chart is just the details.
Get these into your head first; the cells you memorise later will all follow from them.
It is a solved answer, not a hunch
For all 340 hand-and-upcard combinations, one play returns more than the others over the long run. That play is basic strategy. It depends on the rules, so there is no single chart.
It is worth about five points of edge
Basic strategy costs about 0.46% of every bet. Mimicking the dealer costs about 5.7%; never busting, about 6%. Most of that gap is never doubling and never splitting.
Read the dealer's card first
A 2 through 6 breaks between 35% and 42% of the time. A 7 through ace, a quarter of the time or less. Every decision starts there, before you look at your own total.
The expensive mistakes are the quiet ones
Hard 16 against a ten, the decision people argue about, is worth under a percent. Splitting fives, hitting a pair of aces, standing on soft 17 — each is worth twenty-five to fifty times more.
Learn it in three evenings, in this order
Hard totals first — seven lines cover them. Then soft totals. Then pairs. Use the strategy calculator at the table until the chart is yours.