Atlassino Academy · Blackjack · Lesson 7 of 21
A second bet that buys exactly one card: when the chart asks for it, how much the rules let you add, and what each call costs.
A double is a second bet for exactly one more card. You put the second bet down behind the first bet, the dealer gives you one card, and the hand is over. If you have never made the move, open the box below first; what the move is and when a table offers it is the lesson on your options at the table.
Your table lets you double for less than your first bet. You hold hard 11 against an ace and put out a quarter of your first bet as the second bet. Is that better than just taking the card, or worse?
Three hard totals take a second bet: 11 against every dealer card, 10 against 2 to 9, 9 against 3 to 6. No total below 9 takes a second bet, and no total from 12 up. And where a table lets you add less than your first bet, a small addition can do worse than no addition at all.
Leoformer dealer · rules and maths
Doubling is the only move that asks you for more money, so people play it on feeling: some never double at all, others double whenever the hand looks pretty. The chart says when; and where a table lets you add less than your first bet, how much is a decision of its own.
No single card can take a hard 9, 10 or 11 over 21, and a 10 — the commonest card in the shoe — turns them into 19, 20 and 21.
No card can take 11 over 21, and the card most likely to land is a 10, which makes 21. That is why the second bet goes down on 11 whatever the dealer shows.
A 10 makes 20, and no card can take 10 over 21. Against a 10 and an ace the dealer’s own hand ends strong too often for a second bet to pay, so the row for 10 stops there.
A 10 makes 19, and 19 only holds up against a dealer card that goes over 21 often. So 9 takes a second bet only against 3 to 6, the dealer cards that go over 21 most often, and against nothing else.
Six decks · dealer hits soft 17 · double on any two cards · after a split too · the rules this lesson follows
| Hard | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | A |
|---|---|---|---|---|---|---|---|---|---|---|
| 9 | H | Dh | Dh | Dh | Dh | H | H | H | H | H |
| 10 | Dh | Dh | Dh | Dh | Dh | Dh | Dh | Dh | H | H |
| 11 | Dh | Dh | Dh | Dh | Dh | Dh | Dh | Dh | Dh | Dh• |
• Where the sign says the dealer stands on all 17s: 11 against an ace, hit.
And no other total. Never on 8 or less: a 10 takes 8 only to 18, and the chart finds no dealer card weak enough to make a second bet on 18 pay. Never from 12 up: from 12 a 10 takes you over 21, and a hand that can go over is not a hand to put more money on.
Roughly one two-card hand in eight is a hard 9, 10 or 11, so the decision comes round several times an hour, and the three rows read the same at every table in the country. Every other hard total is a hit-or-stand decision, and those rows are in the previous lesson; the whole chart, soft hands and pairs included, is in the Blackjack strategy tool.
Leoformer dealer · rules and maths
Look at the cell for hard 11 against an ace. The chart doubles there, but only because the dealer at this table has to draw on a soft 17. At a table where the dealer stands on soft 17, that same cell — 11 against an ace — turns over and says take the card instead, and a chart printed for such a table shows a hit there. Both charts are right, each for its own table, and the sign beside you says which table you are sitting at.
Getting 11 against an ace wrong — taking the card where the chart doubles — is the cheapest mistake on the three rows: $0.12 a hand on an example bet of $10.
| At some tables | What that means |
|---|---|
| The same again | Exactly your first bet: no more, no less. |
| Up to your first bet | Less is allowed, but how much less is not written down. Ask the dealer. |
| Down to the table minimum | Anything from the table minimum up to your first bet. |
The table minimum is the figure on the sign above the table, next to the maximum and the payouts. At a table that lets you add less, the size of the second bet is your decision.
A double locks you to one card. After a double you take one card and stop, whatever that card is — and on 11 against an ace that lock costs something, because a small card would leave you on 13, 14, 15 or 16, and against an ace you would not stand on any of those totals. A plain hit keeps that door open; a double closes it. So the money you add has to pay for the closed door as well as ride on the card. Every dollar you add earns the same again per dollar, in a straight line, and the line only passes what the plain card is worth once the addition reaches a certain share of your first bet. Add less than that share and you have done worse than not doubling at all.
Hard 11 against an ace: what the hand is worth on average, by the size of the second bet
Four bars, one for each size of second bet, growing in a straight line from a quarter of the first bet to the whole of it. A dashed line marks what taking the card alone is worth. The bars for a quarter and for half fall short of that line; the bar at the marked share reaches it exactly, and the bar for the whole first bet passes it.
Hard 11 against an ace. Each bar is what the hand is worth on average with that size of second bet, and the dashed line is the plain card with no second bet at all. The bars grow in a straight line: the bars for a quarter and for half of the first bet fall short of the plain card, the bar at the marked share reaches it exactly, and the full double passes it.
| Hard | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | A |
|---|---|---|---|---|---|---|---|---|---|---|
| 11 | 0.9% | 0.3% | 0.0% | 0.0% | 0.0% | 25.6% | 31.0% | 37.7% | 33.2% | 79.4% |
| 10 | 1.2% | 0.3% | 0.0% | 0.0% | 0.0% | 29.7% | 37.5% | 58.4% | – | – |
| 9 | – | 60.9% | 38.3% | 27.5% | 22.1% | – | – | – | – | – |
The same three rows as the chart above, now showing how much of the second bet each cell needs. On 10 and 11 against the dealer’s 4, 5 and 6 the share is nothing at all: against those cards you would stand on any total from 13 up, so the lock to one card costs nothing. On 9 the share never drops to nothing, because a small card leaves 9 on a total you would keep drawing on. In every row the share is larger against the dealer’s strong cards than against the weak ones, and 11 against an ace, the last cell of the last row, asks for the most.
So, at a table that lets you add less than your first bet: in most cells of the three rows, half of your first bet already does better than the plain card, and against a weak dealer card any addition at all does. In the few cells that ask for a large share — 11 against an ace above all — the choice is very nearly all or nothing: add most of the first bet, or take the card and keep your money.
Split a pair and you have two hands, each with a bet of its own. Either hand may take a second bet on its first two cards, exactly as if those two cards had been dealt to you fresh — so a split hand that lands on a hard 9, 10 or 11 reads off the same three rows as any other hand.
One exception: a split ace takes one card and stops, so a split ace never has a first-two-cards moment in which to double. Whether a table offers a double after a split at all is a line on its sign; what each line on the sign costs you is the table-rules lesson, and when to split a pair in the first place is the pairs lesson.
Leoformer dealer · rules and maths
The two mistakes run in opposite directions. Keeping the second bet in your pocket on a hand the chart doubles feels like the careful mistake; putting a second bet on a hand the chart does not double feels like the reckless one. On average the two mistakes cost almost exactly the same — and standing on a hand where the card is free to take costs many times more than either mistake.
What each call gives up on average, per hand, on an example bet of $10
Three bars. The careful mistake and the eager mistake are the same length; standing on 11 against a 10 is many times longer than either.
Amounts are in Canadian dollars for an example bet of $10: double the bet, roughly double the amount. Standing on 11 against a 10 costs more than the two mistakes put together, many times over, because no card can take 11 over 21, and standing on 11 throws away a card that costs nothing to take.
each time you take the card on 11 against a 10 instead of doubling. On 10 against a 2 the same habit costs $1.82; on 9 against a 6, $1.24. Keeping the second bet in your pocket feels like the safe choice, and on 9, 10 and 11 it is a habit that costs money on every hand it touches.
Fix: on 9, 10 and 11, read the row before you decide, not your nerve.
each time you double 9 against a 7 — within a cent of the careful mistake. Doubling 8 against a 6 costs $0.22. Doubling 10 against an ace costs $0.62, and unlike doubling 9 against a 7 or 8 against a 6 it turns a hand that comes out ahead on average into a hand that loses on average.
Fix: three totals, three rows. A hand that looks promising and is not in the row for 9, 10 or 11 is not a doubling hand.
The house keeps its edge; the chart only makes the edge smaller. Play every row of the chart and these rules still leave the house 0.53% of every bet with the full chart. Doubling where the chart asks lowers the price of the evening; it does not turn the game round, and the second bet loses as often as the arithmetic says.
Mayaformer floor supervisor · manners, money and breaks
Doubling is the one move where you touch your chips in the middle of a hand, so it helps to know how the move looks from the dealer’s side of the table.
Mayaformer floor supervisor · manners, money and breaks
A double is a second bet, and an evening in which the chart asks for eight doubles is an evening in which more money went onto the felt than you counted at the door. Decide the limit first (Game plan walks you through it), and count the doubles inside that limit.
A losing double is not a reason to double larger on the next hand. If the money starts to feel like money you need, stop and call one of the lines below.
If gambling stops being entertainment, help is available. 19+ in most of Canada; 18+ in Alberta, Manitoba and Quebec. More on responsible gaming.
The practice table is the same one as in the previous lesson, and it keeps your place: level 1 is hard 12 to 16, and doubling comes into its own on level 2, where every hard total is dealt. Its rule selector starts on the set these figures follow — the one published for B.C. tables — and switches to the other two; on the three rows above, nothing changes when it does. Decide with the buttons or the keys H, S, D and R; the table tells you what the chart says, why, and what each choice costs on average. The amounts are for an example bet of $10 unless you pick another one — an example, not a suggested bet. The lesson is one run: every square on the strip below is one hand of it, and they are all there from the start. Only your first move on each hand is scored, and when a level’s squares are full the next level begins by itself. A double here is always the full size of your bet, as the chart assumes; the part-sized double from the section above is an arithmetic question, not a dealt one.
Rules differ by province. Pick the rules closest to the table where you play; this table then answers by the chart for those rules. The bet is only an example for the amounts shown, not a suggested bet.
Dealer
You
Progress stays in this browser; nothing is sent anywhere.
The practice table needs JavaScript. Here is one hand from it, with the answer.
Dealer shows a 7
You hard 16
The chart says: Hit.
Hard 16 against a 7: The dealer card is strong: standing on 16 loses whenever the dealer finishes on 17 or more, 73.8% of hands against a 7.
Average result per hand on an example bet of $10 (a minus means money lost): stand −$4.77 · hit −$4.09 · double −$8.17 · surrender −$5.00. Standing instead costs about $0.68 more each time.
One strip, no rounds. Every square on the strip is one hand of this lesson, and they are all there from the start. The square keeps your first move on that hand; later moves in the same hand are still checked and explained. When a level’s squares are full the next level begins by itself, with no button in between; the level buttons above the table are all live, so you can also jump and come back.
Levels. Level 1: hard 12 to 16 against every dealer card. Level 2: hard 5 to 19, doubles included. Level 3: hard 9 to 16 against every dealer card; the clock is optional. Level 1 belongs to the previous lesson; it is here so that the ladder does not restart when you arrive from search.
Amounts. The figures are averages for the example bet you pick: $5, $10 or $25. There is no balance, and nothing adds up from one hand to the next. At the end of the run, one line adds up what your first moves cost against the chart’s.
Dealing. Cards come from a shuffled 6-deck shoe with a fresh seed each visit. A hand that does not belong to the level is set aside unseen, so the shoe runs down faster than at a real table. The correct play is the chart’s cell for the table rules you pick, and the averages come from the same engine as the chart above.
Mayaformer floor supervisor · manners, money and breaks
Five quick ones. Pick an answer, then check it. No timer, no points: just whether it stuck.
Worse. Against an ace a part-sized double only starts doing better than the plain card at 79.4% of the first bet, and a quarter of the first bet is nowhere near that share. On an example bet of $10 that share is $7.94. The first answer is the tempting one, and the rules encourage it: they allow the small addition, after all. What the rules allow and what the addition is worth are two different questions.
19+ (18+ in AB, MB, QC) · Play responsibly · help, day or night: Gambling Support BC 1-888-795-6111, 24 hours
Rules. The figures on this page follow one published set of table rules: six decks, the dealer drawing on soft 17, blackjack paid 3 to 2, doubling on any two cards and after a split, and no face-down dealer card. It is a preset for learning, not a statement about any one casino — the three rows of the chart are the same on every Canadian rule set we have read, but the rest of a table’s terms are on its own sign.
Numbers. Every figure is worked out when the page is built, by the same engine as our Blackjack strategy tool, which is checked cell by cell against published charts. A mistake’s cost is the average result of the chart’s play minus that of the mistake, per hand, shown in dollars for an example bet of $10 with each average rounded to the cent first. The house edge assumes the full chart, soft hands and pairs included, and cards shuffled after every hand. How often a hard 9, 10 or 11 turns up is an exact count over the two-card hands of a six-deck shoe, not an engine figure.
The share a part-sized double has to reach. A full double stakes two units for one card, so the card is worth half that average per unit staked. Add a share s instead and the hand stakes 1 + s units — the card and the settlement do not change with the money on them — so its average is 1 + s times the per-unit figure. Set that equal to the average of taking the card alone and solve for s. The bars for 11 against an ace are drawn from the same two averages: each bar’s length is 1 + s halves of the full double, and the dashed line stands at the plain card. No casino page or reference we read publishes this figure; it is ours, worked out here.
Hosts. Leo and Maya are illustrated characters. Their backstories, a former dealer and a former floor supervisor, are written for the course: neither is a real person, and neither speaks for any casino. The rules and numbers on this page come from the sources it cites, not from their experience.
No promise. Blackjack is played against the house. The chart lowers the price of playing; nothing on this page removes that price, and nothing here tells you how an evening will end.
Eleven against an ace, as one province prints it
With 11, double if the dealer has 2 through 10, hit if the dealer has an ace
How much you may add, and where the floor comes from
In our words: The extra bet for a double can be up to the size of your first bet, and no less than the table minimum.
Section 1.0 Basic Blackjack, 4.3 to 4.3.4.a
BCLC · Rules of Play for Table Games — Blackjack · read
Minimums and maximums, and maximum payouts are posted at the table.
Section Blackjack
Two rule books on how much a double is
DOUBLE DOWN, i.e. bet an additional amount equal to their initial bet on a two-card hand, except if the hand is a blackjack.
Section The player options
In our words: The extra bet for a double can be up to the size of your first bet, and no less than the table minimum.
Section 1.0 Basic Blackjack, 4.3 to 4.3.4.a
BCLC · Rules of Play for Table Games — Blackjack · read
The floor under a smaller double
In our words: The extra bet for a double can be up to the size of your first bet, and no less than the table minimum.
Section 1.0 Basic Blackjack, 4.3 to 4.3.4.a
BCLC · Rules of Play for Table Games — Blackjack · read
Doubling after a split, in three rule books
In our words: Doubling is allowed on hands that came from a split.
Section 1.0 Basic Blackjack, 4.4 to 4.4.9
BCLC · Rules of Play for Table Games — Blackjack · read
Players may also double down on each hand after SPLITTING two cards of the same value, except in the case of a pair of aces.
Section The player options
You may also "double down" on the first two cards of each hand after the split, except when splitting Aces.
Section Blackjack terms
Split aces take one card
In our words: A pair of aces can be split one time, and each ace then gets just one card.
Section 1.0 Basic Blackjack, 4.4 to 4.4.9
BCLC · Rules of Play for Table Games — Blackjack · read
In the case of a pair of aces, players can split only once and hit for only one additional card for each hand.
Section The player options
When splitting aces, each ace gets only one card.
The dealer’s rule, and where it is written
In our words: draw on 16 or less, and on soft 17;
In our words: and stop drawing at hard 17.
Section 1.0 Basic Blackjack, 8.5 to 8.9
BCLC · Rules of Play for Table Games — Blackjack · read
This means that the dealer will hit their hand up to and including an ace or aces that can be totaled as either 7 or 17.
Section Blackjack
After revealing the house's face-down card, the dealer completes the house's hand, if necessary, according to the house strategy indicated at the table which may either be:
HIT on a count of soft 17 or less and STAND on a count of hard 17 or more, or
HIT on a count of 16 or less and STAND on a count of (soft or hard) 17 or more.
Section The house strategy
The Dealer must draw cards according to the rules posted on the table;
This means that the dealer will hit their hand up to and including an ace or aces that can be totaled as either 7 or 17.
"Dealer Must Stand on 17" - This means that the dealer will hit their hand on anything less than a total of 17.
Section Blackjack
The rule and the sign it points at
In our words: The extra bet for a double can be up to the size of your first bet, and no less than the table minimum.
Section 1.0 Basic Blackjack, 4.3 to 4.3.4.a
BCLC · Rules of Play for Table Games — Blackjack · read
Minimums and maximums, and maximum payouts are posted at the table.
Section Blackjack
Doubling after a split
In our words: Doubling is allowed on hands that came from a split.
Section 1.0 Basic Blackjack, 4.4 to 4.4.9
BCLC · Rules of Play for Table Games — Blackjack · read
Players may also double down on each hand after SPLITTING two cards of the same value, except in the case of a pair of aces.
Section The player options
You may also "double down" on the first two cards of each hand after the split, except when splitting Aces.
Section Blackjack terms
In our words: A pair of aces can be split one time, and each ace then gets just one card.
Section 1.0 Basic Blackjack, 4.4 to 4.4.9
BCLC · Rules of Play for Table Games — Blackjack · read
In the case of a pair of aces, players can split only once and hit for only one additional card for each hand.
Section The player options
When splitting aces, each ace gets only one card.
Doubling down: the move
In our words: you may double on any first two cards by adding a second bet.
In our words: A doubled hand gets exactly one more card.
Section 1.0 Basic Blackjack, 4.3 to 4.3.4.a
BCLC · Rules of Play for Table Games — Blackjack · read
DOUBLE DOWN, i.e. bet an additional amount equal to their initial bet on a two-card hand, except if the hand is a blackjack.
In any event, once the player doubles down, they are dealt one last card.
Section The player options
In our words: A doubled hand gets exactly one more card.
Section 1.0 Basic Blackjack, 4.3 to 4.3.4.a
BCLC · Rules of Play for Table Games — Blackjack · read
In any event, once the player doubles down, they are dealt one last card.
Section The player options
Only on the first two cards
You can only double down after you receive your first two cards and before drawing another card.
The dealer’s rule, and the sign that carries it
In our words: draw on 16 or less, and on soft 17;
In our words: and stop drawing at hard 17.
Section 1.0 Basic Blackjack, 8.5 to 8.9
BCLC · Rules of Play for Table Games — Blackjack · read
This means that the dealer will hit their hand up to and including an ace or aces that can be totaled as either 7 or 17.
Section Blackjack
After revealing the house's face-down card, the dealer completes the house's hand, if necessary, according to the house strategy indicated at the table which may either be:
HIT on a count of soft 17 or less and STAND on a count of hard 17 or more, or
HIT on a count of 16 or less and STAND on a count of (soft or hard) 17 or more.
Section The house strategy
The Dealer must draw cards according to the rules posted on the table;
This means that the dealer will hit their hand up to and including an ace or aces that can be totaled as either 7 or 17.
"Dealer Must Stand on 17" - This means that the dealer will hit their hand on anything less than a total of 17.
Section Blackjack
A double of the same size
DOUBLE DOWN, i.e. bet an additional amount equal to their initial bet on a two-card hand, except if the hand is a blackjack.
Section The player options
A double up to the size of your bet
you may place a wager up to the amount of your original beside your bet.
This indicates to the Dealer that you are doubling down and you only get one more card.
Section Blackjack terms
Doubling for less, and its floor
In our words: The extra bet for a double can be up to the size of your first bet, and no less than the table minimum.
Section 1.0 Basic Blackjack, 4.3 to 4.3.4.a
BCLC · Rules of Play for Table Games — Blackjack · read
What the sign carries
Minimums and maximums, and maximum payouts are posted at the table.
Section Blackjack
What the rules allow
In our words: The extra bet for a double can be up to the size of your first bet, and no less than the table minimum.
Section 1.0 Basic Blackjack, 4.3 to 4.3.4.a
BCLC · Rules of Play for Table Games — Blackjack · read
you may place a wager up to the amount of your original beside your bet.
This indicates to the Dealer that you are doubling down and you only get one more card.
Section Blackjack terms
Doubling after a split
In our words: Doubling is allowed on hands that came from a split.
Section 1.0 Basic Blackjack, 4.4 to 4.4.9
BCLC · Rules of Play for Table Games — Blackjack · read
Players may also double down on each hand after SPLITTING two cards of the same value, except in the case of a pair of aces.
Section The player options
You may also "double down" on the first two cards of each hand after the split, except when splitting Aces.
Section Blackjack terms
Split aces take one card
In our words: A pair of aces can be split one time, and each ace then gets just one card.
Section 1.0 Basic Blackjack, 4.4 to 4.4.9
BCLC · Rules of Play for Table Games — Blackjack · read
In the case of a pair of aces, players can split only once and hit for only one additional card for each hand.
Section The player options
When splitting aces, each ace gets only one card.
What basic strategy does, in an operator’s own words
Blackjack has an element of skill, but making the statistically correct play does not ensure a winning outcome.
By following basic strategy you can reduce the house advantage and your cost of play.
Where the extra bet goes
In our words: The extra chips for a double go behind your first bet.
Section 1.0 Basic Blackjack, 4.3 to 4.3.4.a
BCLC · Rules of Play for Table Games — Blackjack · read
Place a chip next to the original chip bet on the hand.
you may place a wager up to the amount of your original beside your bet.
This indicates to the Dealer that you are doubling down and you only get one more card.
Section Blackjack terms
One card after a double
In our words: A doubled hand gets exactly one more card.
Section 1.0 Basic Blackjack, 4.3 to 4.3.4.a
BCLC · Rules of Play for Table Games — Blackjack · read
In any event, once the player doubles down, they are dealt one last card.
Section The player options
Your extra bet when the dealer has blackjack
In our words: If the dealer has a blackjack, a doubled hand loses only its first bet; the extra chips come back.
Section 1.0 Basic Blackjack, 4.3 to 4.3.4.a
BCLC · Rules of Play for Table Games — Blackjack · read
In our words: If the dealer has a blackjack, a split hand loses only its first bet; the extra bet for the split comes back.
Section 1.0 Basic Blackjack, 4.4 to 4.4.9
BCLC · Rules of Play for Table Games — Blackjack · read
In the event that the house does not get a blackjack and the house's second card has not yet been revealed, players may:
Section The player options
No double on a blackjack
In our words: You cannot double on a blackjack.
Section 1.0 Basic Blackjack, 4.3 to 4.3.4.a
BCLC · Rules of Play for Table Games — Blackjack · read
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