Single Deck Blackjack
The best odds in blackjack — or the worst, depending entirely on the payout.
≈0.15% at 3:2 house edge with S17 and doubling on any two cards. The same game paying 6:5 runs about 1.45% — roughly ten times worse, and worse than almost any shoe game.
About Single Deck Blackjack
One deck, dealt from the hand, often shuffled every few rounds. With a 3:2 payout and the dealer standing on soft 17, single deck blackjack offers the lowest house edge of any blackjack game on the floor — under 0.2%, and better still with liberal doubling.
It is also the most common trap in the modern casino. Because "single deck" reads as favourable, it is the game most often paired with a 6:5 blackjack payout instead of 3:2. That one change adds roughly 1.4% to the house edge and turns the best game available into one of the worst.
The arithmetic is worth stating plainly: a single-deck game paying 6:5 is a worse bet than an eight-deck shoe paying 3:2. Deck count is the headline; the payout is what actually decides the game.
vs
A hand that plays differently here —
Hard 11 vs dealer Ace:
Double
rather than hit on a shoe.
Rules at a glance
| Decks | 1 |
|---|---|
| Dealer on soft 17 | Varies — S17 is much better for you |
| Hole card | Yes — dealer peeks on a 10 or Ace |
| Double down | Often restricted to hard 9–11 or 10–11 |
| Double after split | Frequently not allowed |
| Splitting | Often limited to two hands |
| Surrender | Rarely offered |
| Blackjack pays | 3:2 or 6:5 — check before you sit |
| Penetration | Often shuffled every 1–2 rounds |
Rule sets vary between casinos and between online operators. Always check the table or the game's rules screen — the blackjack payout and the dealer's soft 17 rule move the house edge more than anything else on this page.
What makes it different
The payout decides everything
A 6:5 payout costs about 1.4%, overwhelming every other rule on the table.
Card removal is dramatic
With one deck, a single card seen shifts the composition sharply — which is why composition-dependent plays exist here and nowhere else.
Restricted doubling
Casinos claw back the deck advantage by limiting doubles, often to 9–11 or even 10–11.
Shallow penetration
Frequent shuffling is the main defence against counters and severely limits how far any count can develop.
How basic strategy changes
These are the decisions that differ from the standard chart. Everything not listed here is played the same way.
| Hand | Standard play | In Single Deck | Why |
|---|---|---|---|
|
vs
Hard 11 vs dealer Ace |
Hit on a shoe | Double | Removing your own cards from a single deck shifts the odds enough to justify it. |
 vs
Pair of 7s vs dealer 10 |
Hit on a shoe | Stand | A composition-dependent play: two sevens removed makes the remaining deck ten-rich. |
  vs
Hard 8 vs dealer 5 or 6 |
Hit on a shoe | Double where allowed | Single deck strategy doubles more aggressively against weak up-cards. |
  vs
Soft 13 (A,2) vs dealer 4 |
Hit on a shoe | Double where allowed | Another single-deck-only double, subject to the table's doubling rules. |
Drill the underlying decisions first with the basic strategy trainer, or look up any single hand in the strategy calculator.
What it means for card counting
Single deck is where counting is mathematically most powerful and practically most difficult. The count swings hard — one card is worth 1/52 of the deck — so true count conversion happens in fractions of a deck and small errors matter. Set against that, penetration is usually terrible and casinos watch single-deck games closely. Many counters train on single deck precisely because it is unforgiving, then play shoes.
Practise on a matching shoe in the card counting trainer — it lets you set the deck count and run true count conversion drills.
Where you will find it
Downtown Las Vegas and northern Nevada still deal 3:2 single deck. On the Strip, single deck almost always means 6:5. Online single-deck games often shuffle after every hand, which removes any counting opportunity entirely.
Frequently asked questions
Is single deck blackjack always the best game?
No — only at 3:2. A single deck game paying 6:5 has a house edge around 1.45%, which is worse than a typical six- or eight-deck game paying 3:2. Read the payout before the deck count.
Why is single deck strategy different?
Because your own cards materially change what is left. In one deck, holding two sevens genuinely alters the odds of the next card, which produces composition-dependent plays that do not exist on a shoe.
Can you count cards in a single deck game?
Yes, and the edge per unit of count is the largest in blackjack. The obstacle is penetration: if the dealer shuffles every round or two, the count never gets the chance to develop.