Blackjack basic strategy: the chart that cuts the house edge
Stoopid Pigeon Editorial· · 8 min read
Blackjack rewards the player who knows exactly what to do with each hand. Unlike most casino games, where the only real decision is how much to bet, blackjack hands carry genuine choices — hit, stand, double, split — and those choices have right and wrong answers. Make them by the chart and the house edge shrinks to one of the smallest on the floor. Guess, and you hand the casino several percent it never had to earn.
That chart is called basic strategy: the mathematically optimal play for every hand against every dealer upcard. It doesn’t promise winning sessions — no strategy does that against a built-in edge — but it does mean paying the lowest possible price to play. This guide covers how the game works, why its edge is so low, the rules of thumb that do most of the work, the bets to refuse, and the table conditions that quietly change everything.
How blackjack works
The goal is to beat the dealer’s hand without going over 21. Number cards count their face value, face cards count 10, and an ace counts as 1 or 11 — whichever helps. A hand totalling more than 21 “busts” and loses immediately, regardless of what the dealer does.
After the bets are placed and cards are dealt, the player acts first and chooses how to play the hand. The dealer follows fixed rules: they draw until reaching a set total — typically standing on 17 — with no choices of their own. Because the player acts first, busting before the dealer ever draws is where a lot of the house’s edge comes from. The rest of the game is about playing each total in the way the math says loses the least.
For a broader sense of why some casino bets cost far more than others, the Casino Insights section is a good starting point.
Why blackjack has one of the lowest house edges in the casino
The house edge is the share of each wager the house expects to keep over time. In blackjack, with correct basic strategy, that figure is typically around 0.5% — though it varies meaningfully with the rules in force. That is dramatically lower than most of the floor: single-zero roulette sits near 2.7%, double-zero roulette near 5.26%, and a typical slot around 4%.
The reason blackjack can be so cheap is that the player’s decisions matter. The drawing rules give the dealer some structural advantage — players act first and can bust before the dealer draws — but skilful play claws most of it back. The catch is that “around 0.5%” assumes the player makes the optimal decision every single hand. Deviate, and the edge climbs fast. For a fuller treatment of how this number is built and what it means, see what is the house edge.
With correct basic strategy, blackjack's house edge is typically around 0.5% — meaning the math expects to keep roughly $0.50 of every $100 staked. Play the same hands by instinct and that figure can climb several times higher. The chart is the difference.
What “basic strategy” actually is
Basic strategy is not a betting system and it isn’t card counting. It is simply the mathematically optimal decision for every possible hand against every dealer upcard, worked out by running the game’s odds over millions of simulated hands. For any combination of your cards and the dealer’s visible card, there is one play that loses the least over the long run — and basic strategy is the complete table of those plays.
It is usually presented as a colour-coded grid: your hand down the side, the dealer’s upcard across the top, and a cell telling you whether to hit, stand, double or split. Crucially, basic strategy assumes no counting — it treats every card as equally likely to come next. (Tracking which cards have been dealt is a separate, more demanding skill covered in card counting explained.) For ordinary play, the chart is the whole job, and most of its value lives in a handful of rules.
The rules of thumb that do most of the work
The full chart has dozens of cells, but a short list of high-confidence rules captures most of the benefit:
- Always split aces and 8s. Two aces played as one hand is a weak 12; split, each ace becomes the start of a strong hand. A pair of 8s is 16 — the worst total in the game — so splitting into two fresh hands is almost always better.
- Never split 10s or 5s. Two 10s is already a 20, an excellent total; breaking it up to chase something better is a losing move. A pair of 5s is a hard 10 and is better played as a strong doubling or hitting hand than split into two weak 5s.
- Double down on hard 11. An 11 can’t bust on the next card and lands on a 10-value card often, so putting more money out is the percentage play against most dealer upcards.
- Stand on hard 17 or higher. The bust risk of hitting outweighs the slim improvement, so a hard 17+ stands every time.
- Mind the dealer’s upcard. When the dealer shows a weak card (typically 4, 5 or 6, where they’re more likely to bust), the player stands on more borderline totals and lets the dealer take the risk. When the dealer shows a strong card (7 through ace), the player hits more aggressively to try to make a competitive hand.
These thresholds are the spine of the chart. The remaining cells — soft hands containing an ace, less common pairs, double-after-split situations — refine the edge further, which is why serious players keep the full grid handy rather than relying on memory alone.
Why insurance and “even money” are bad bets
When the dealer’s upcard is an ace, the table offers insurance: a side bet, usually up to half the original wager, that pays if the dealer has blackjack. It is framed as protection. It is really a separate, high-house-edge bet on whether the dealer’s hole card is a 10 — and the payout doesn’t reflect how often that actually happens. Basic strategy says decline insurance, every time, regardless of how strong the player’s own hand looks.
“Even money” is the same bet wearing a friendlier name. It’s offered when the player has a blackjack and the dealer shows an ace: take a guaranteed 1:1 payout instead of the 3:2 the blackjack would otherwise pay. The math comes out the same as taking insurance, and over the long run it costs the player. Turn it down and take the chance at the full 3:2 payout.
Rule variations that change the edge
Two blackjack tables can look identical and charge very different prices. The fine print on the felt is what determines whether that “around 0.5%” figure holds. The variations that matter most:
- 3:2 vs 6:5 blackjack payouts. This is the big one. A natural blackjack paying 3:2 returns $15 on a $10 bet; a 6:5 table returns only $12. That difference roughly quadruples the edge contributed by naturals and is the single fastest way to turn a good game into a bad one. Look for “Blackjack pays 3 to 2” printed on the table and avoid 6:5 games.
- Dealer hits or stands on soft 17. A “soft 17” is a 17 made with an ace counted as 11 (for example, ace-6). Tables where the dealer stands on soft 17 are slightly better for the player; tables where the dealer hits soft 17 nudge the edge up in the house’s favour.
- Number of decks. Fewer decks generally favour the player by a small margin, all else equal. Single- and double-deck games carry a marginally lower edge than the common six- or eight-deck shoes — though they often pair that with worse payout or doubling rules, so the whole rule set has to be read together.
- Double-after-split and re-splitting. Being allowed to double down after splitting a pair, and to re-split, gives the player extra optimal plays and lowers the edge a touch. Restrictions on these quietly raise it.
The takeaway: the rules printed on the table can swing the house edge by more than basic strategy itself saves. A perfectly played 6:5 game can cost more than an imperfectly played 3:2 one. For the wider picture of where cheap and expensive bets sit across the floor, our piece on table games versus slots makes the same point about reading the conditions before you sit down — and baccarat tips shows the same logic in another low-edge game.
Bankroll and pace
Basic strategy minimises the edge, but it can’t eliminate it — over enough hands the house still expects to win. That makes the two things outside the chart matter just as much: how much you bet and how many hands you play per hour. A faster table means more decisions per hour and more total exposure to the edge, even at the same stake.
A simple approach: set a session budget before sitting down and treat it as the cost of an evening’s entertainment, bet a flat unit rather than chasing losses, and decide a stop in both directions — a loss limit and a win target. Blackjack’s low edge makes a bankroll last longer than almost any other game on the floor, but only if the stake stays steady and the pace stays sane. Our bankroll management guide covers the mechanics in detail.
Quick reference
- Beat the dealer to 21 without busting. The dealer has no choices — they draw to a fixed total, typically standing on 17.
- Play basic strategy — the optimal move for every hand vs the dealer’s upcard. It pulls the edge down to typically around 0.5%.
- Always split aces and 8s; never split 10s or 5s; double hard 11; stand on hard 17+. Those rules carry most of the benefit.
- Decline insurance and “even money.” Both are high-cost side bets dressed up as protection.
- Insist on 3:2 payouts — a 6:5 table roughly quadruples the edge on naturals. Check the felt before you sit.
- Slow down and bet flat. Pace and stake decide how much that small edge costs over a night.
Played by the chart at a 3:2 table, blackjack is about as fair a game as a casino offers. Played on guesswork at a 6:5 table, it quietly becomes one of the more expensive ones. The chart — and the table you choose to sit at — is the whole difference.
Frequently asked questions
What is basic strategy in blackjack?
Basic strategy is the mathematically optimal decision — hit, stand, double or split — for every possible hand against every dealer upcard. It's worked out from the game's odds and assumes no card counting. Following it pulls the house edge down to typically around 0.5%, depending on the rules.
How low can the house edge in blackjack go?
With correct basic strategy the house edge is typically around 0.5%, though the exact figure varies with the rules — payouts, whether the dealer hits soft 17, the number of decks, and the doubling and splitting rules all move it. That's one of the lowest edges of any game in the casino.
Which hands should I always split?
Always split aces and 8s. Two aces played together make a weak 12, while split they each start a strong hand; a pair of 8s is 16, the worst total in the game, so two fresh hands are almost always better.
Which pairs should I never split?
Never split 10s or 5s. Two 10s already make 20, an excellent total worth keeping; a pair of 5s is a hard 10, better played as a single strong hand than broken into two weak fives.
When should I double down?
The most reliable double is a hard 11 — it can't bust on the next card and lands on a 10-value card often, so it's the percentage play against most dealer upcards. The full chart lists other doubling spots, mostly soft hands and certain totals against weak dealer cards.
Should I ever take insurance?
No. Insurance is a separate high-house-edge side bet on whether the dealer's hole card is a 10, and the payout doesn't reflect how often that happens. Basic strategy says decline it every time, no matter how strong your own hand looks.
What is "even money" and should I take it?
Even money is offered when you have a blackjack and the dealer shows an ace: a guaranteed 1:1 payout instead of the usual 3:2. The math works out the same as taking insurance, and over time it costs the player. Decline it and take the chance at the full 3:2.
Why does a 6:5 blackjack payout matter so much?
A 3:2 payout returns $15 on a $10 blackjack; a 6:5 table returns only $12. That difference roughly quadruples the edge contributed by naturals and is the fastest way to turn a good game into a bad one. Look for "Blackjack pays 3 to 2" and avoid 6:5 tables.
Does the dealer hitting or standing on soft 17 change the odds?
Yes, slightly. A soft 17 is a 17 made with an ace counted as 11. Tables where the dealer stands on soft 17 are a little better for the player; tables where the dealer hits soft 17 nudge the edge up in the house's favour. It's worth checking the rule before sitting down.
Does the number of decks affect basic strategy?
The optimal plays barely change, but fewer decks generally favour the player by a small margin. Single- and double-deck games carry a marginally lower edge than six- or eight-deck shoes, though they often come with worse payout or doubling rules, so read the whole rule set together.
Is basic strategy the same as card counting?
No. Basic strategy assumes every card is equally likely to come next and tells you the best play for each hand. Card counting tracks which cards have been dealt to gauge when the remaining deck favours the player — a separate, far more demanding skill. Basic strategy is the foundation everyone should learn first.
Does playing perfect strategy guarantee I'll win?
No. Basic strategy minimises the house edge but can't remove it, so over enough hands the house still expects to come out ahead. What it does is ensure you pay the lowest possible price to play, which makes a bankroll last far longer than guesswork would.