Blackjack Odds: Basic Strategy, Dealer Bust Rates and What the Rules Cost

Blackjack is the one game in the building where the arithmetic is not settled before you sit down. Roulette fixes its house edge at 2.70% and leaves you nothing to decide. Blackjack hands you a decision on every deal, and the quality of those decisions moves the number by more than a factor of three.

That makes blackjack odds a different kind of subject, and it is why this page is built around a basic strategy matrix rather than a number. Unlike roulette odds there is no single figure to quote. There is a floor of roughly 0.5% for a player making every correct play against standard rules, a ceiling somewhere past 2% for a player guessing, and a set of table rules that shift the floor before a card is dealt.

Dealer bust rates, and why the upcard decides everything

Every correct decision in blackjack is a response to one card: the dealer’s upcard. It is the only information you have about a hand that is not yet played, and it is enough, because the dealer has no choices at all. The dealer draws to a fixed rule, which means the probability of that hand breaking can be computed exactly.

That is the dealer bust rate, and the chart divides the table into two halves and explains most of the basic strategy matrix on its own. Against a two through six the dealer breaks roughly four times in ten, so a weak hand of yours is often best left alone: standing on twelve against a four is not timidity, it is declining to bust when the dealer is likely to do it for you. Against a seven or higher the dealer holds a hand that usually finishes, and a weak total of yours has to be improved rather than protected.

The dealer bust column for an ace is the one to notice. A dealer showing an ace breaks under 12% of the time, less than a third as often as a dealer showing a five. It is the single worst card you can be facing, and it is the reason several plays that look reckless against low cards become correct against an ace.

The full basic strategy matrix

There is nothing to interpret in the basic strategy matrix. Find your hand on the left, find the dealer’s upcard along the top, read the cell. The matrix assumes the common multi-deck game: four to eight decks, dealer stands on soft 17, doubling after a split permitted.

Hard totals: no ace, or an ace counted as one. H hit, S stand, D double if permitted otherwise hit

Soft totals: a hand containing an ace counted as eleven

Pairs, where doubling after a split is permitted. P split the pair

Two cells in that matrix account for most of the arguments at a real table. Splitting eights against a ten looks like throwing good money after bad, and it is still correct: sixteen is the worst total in the game, and two hands of eight are each less bad than one hand of sixteen. Standing on twelve against a four feels passive, and it is correct for the reason the bust chart gives.

What the table rules cost before a card is dealt

The house edge is not a property of blackjack. It is a property of the particular table, and the rules printed on the felt move it more than most players expect. The figures below are the standard adjustments, in percentage points, applied to an otherwise typical multi-deck game.

Effect of common rule variations on the house edge, in percentage points

One line on that table dwarfs the rest. A 6:5 payout on a natural adds nearly 1.4 percentage points, which is more than every other variation combined and enough to make the best game in the building a worse proposition than European roulette. It is also the variation most easily missed, because it is printed on the felt in the same type as everything else and changes nothing about how the game feels to play.

Everything else on the list is small individually and worth checking collectively. A shoe game that hits soft 17 and forbids doubling after a split gives up about a third of a point before any decision is made, which is most of the advantage basic strategy was going to earn back.

Where blackjack odds sit against everything else

On blackjack odds alone, correct play puts the game at roughly 0.5%, ahead of the baccarat banker bet at 1.06% and the craps pass line at 1.41%, both of which are charted alongside the roulette odds and the house edge of the common games. Nothing on a casino floor beats it. What that half-point costs over an actual session, rather than per hand, is set out under the house edge per hour.

The comparison carries an obligation, though. Baccarat and roulette ask nothing of the player and deliver their published edge automatically. Blackjack’s 0.5% is conditional on making the correct decision on every hand, and the matrix above is the entire condition. A player who follows it has the best odds available, which still means an expected loss: basic strategy makes the edge as small as the rules allow, and it does not remove it or turn it around. A player who improvises has a worse game than roulette while believing they have a better one. Everything here about blackjack odds assumes the multi-deck game named above; change the table rules and the arithmetic changes with them.

Payout percentages published and audited rather than derived from a strategy matrix work differently, and are covered under return to player.

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