# Single Deck Blackjack

Blackjack is available in over a hundred variations, but the variants that play with a single deck are still considered the Holy Grail of 21. Many players erroneously assume it is impossible to beat shoe games and insists single deck blackjack is the best variation one can possibly find on the casino floor.

And indeed, single deck blackjack yields a very low house edge of around 0.15% with optimal rules but you can reduce it even further through perfect basic strategy play and card counting. Notice that we said “optimal rules”, which generally include the ability to double down on any two starting cards, doubling after a split (DAS), a dealer standing on soft 17s (S17), splitting pairs to four hands or more, and blackjacks paying at a 3-to-2 ratio.

Sounds great, right? Well, here is the sad truth for you – single deck blackjack in its pure form has become an obsolete game. After American Professor of Mathematics Edward O. Thorp introduced card counting to the general public in 1962, casinos added multiple decks to their blackjack tables in an attempt to increase their edge and prevent advantage players from exploiting this profitable game.

Single deck variants were still available although the casinos severely crippled them through various rule adjustments. Meanwhile, the game continued to be aggressively advertised as “Single Deck Blackjack” to unsuspecting patrons in an attempt to lure them into playing an otherwise unprofitable variation.

But let’s cut to the chase. In this article, we discuss the adjustments to the rules of play in single deck blackjack, why they are detrimental to you in the long run, and what the pros and cons of this variation of the game are.

## Rules of Play at Single Deck Blackjack Tables

The objective in single deck blackjack (played with a full deck of 52 cards) is the same as that in multiple-deck variations. You need a hand whose value is closer to 21 than that of the dealer but without going over.

The players again have a choice from hitting, standing, doubling, splitting pairs, and accepting insurance when the dealer’s upcard is an Ace. Insured winning bets return standard payouts of 2 to 1. The player and dealer push on hands of equal value, with the player having their original bet returned. Cards are reshuffled after every round.

One major difference you will undoubtedly notice has to do with table etiquette. The players receive their cards face-down whereas the dealer has only one of their two cards exposed. You are permitted to handle your cards manually as long you do so with one hand only and keep them over the table.

This is where things start to go downhill rules-wise. Most landbased casinos that still operate single deck tables have tweaked the rules so that they have a pronounced negative effect on the house edge from a player’s perspective. We have listed said adjustments below:

• The dealer hits soft totals of 17.
• Blackjacks pay 6 to 5 (or at least in most landbased casinos still offering the game). In some single deck variants, players are offered even money (1 to 1) for their blackjacks when the dealer’s exposed card is an Ace.
• Players are allowed one split and can hit split pairs multiple times. An exception is made for split Aces where you receive only one extra card per Ace. A split Ace and a ten-value card count for a regular 21, not blackjack.
• Doubling down is restricted to two-card totals of 9, 10, and 11. Some variants are even more restrictive allowing double downs on totals of 10 and 11 only. Doubling down after a split (DAS) is often not an option.
• Surrendering is generally not allowed.

These adjustments cause the house edge to spiral to nearly 2% in some single deck variations. As you can see, things are looking far from perfect but the biggest problem here has to do with the reduction of the payouts on your naturals. Let’s see why.

Standard Single Deck Blackjack Rule
Dealer Hits Dealer hits on soft 17
Blackjack Payout 6 to 5 or even money if dealer shows an Ace
Splitting Players are allowed single split
Hitting after a Split Players can hit split pairs multiple times except for Aces that allow only one additional card
Double Down Players are allowed to double down on totals of 9, 10, or 11 only; some variants allow double down only on totals of 10 and 11
Double Down After Split Often this feature is not allowed
Surrender Often this option is not available

## Single Deck Blackjack Gameplay

### ‘Blackjack Pays 6 to 5’

A typical blackjack game offers a payout of 3 to 2 on naturals unless the player pushes with the dealer. In the single deck variants available across landbased casinos today, players are usually paid at a ratio of 6 to 5. This practically means each time you get a blackjack with a \$10 bet, you receive only \$12 in net profits.

In contrast, a 3-to-2 payout yields net profits of \$15 for a blackjack with a \$10 bet. Here the casino gets to keep \$3 on every natural you are paid at reduced odds, which ultimately causes you to lose money. You can calculate your expected loss when you multiply the number of rounds you play per hour by the house edge, the number of hours played, and the amount you bet per hand.

The average number of hands you go through in between naturals is around 21. If the house keeps \$3 from your blackjacks when you are flat betting \$10 per hand, it practically retains around 30% of one of your wagers every 21 hands you play, which corresponds roughly to 1.40% per hand.

Keep in mind the minimums at some tables start at \$25. If you increase your flat bets to \$25 per hand, play for an hour and go through one hundred hands, you will lose around \$36 due to this payout reduction alone.

### Even Money on Player Blackjacks When Dealer Shows an Ace

In some single deck variations of the game, there is a further reduction in the payouts on naturals. When the player has been dealt a blackjack but the dealer exposes an Ace, the player is offered an even-money payout on their natural. The player can accept or decline the reduced payout before the dealer reveals their hole card.

Accepting the even-money payout is practically the same thing as taking insurance and is just as detrimental to the player. Let’s consider a couple of examples to better demonstrate what we mean. If we suppose you wager \$10 and get dealt a blackjack against a dealer with an exposed Ace, you can immediately win the same amount if you accept the even-money payout.

Now, imagine the same scenario, only this time you decide to insure your blackjack for \$5 instead of taking even money (insurance offers a payout of 2 to 1). There are two possible outcomes in this situation. Provided that the dealer indeed has a natural, you will collect \$10 from your \$5 insurance and push with them with your blackjack. Your net profits in this scenario amount to \$10 (same as taking even money).

However, if the dealer does not have a natural, you will lose your \$5 insurance and collect \$15 from your blackjack, in which case you again net a \$10 profit. Of course, this applies only when your blackjacks are paid at the standard rate of 3 to 2. Obviously, a reduction of 6 to 5 will cause you to collect only \$12 in the above scenario where you lose your insurance bet, which is to say you will net a profit of \$7 on top of your initial \$10 stake.

Now, let’s examine the following situation in a six-deck blackjack game played according to the standard rules where naturals return a 3-to-2 payout. You are the only player at the table, bet \$20, and receive an A-Q blackjack on the very first round. Much to your displeasure, the dealer also exposes an Ace.

## Pros and Cons of Single-Deck Games

Now that we have gone through the rules and explained how some of them put the player at a disadvantage, you are probably wondering if there are any dividends to playing single deck blackjack. In fact, there are some advantages although the negatives greatly outnumber the positives.

### How Single-Deck Blackjack Benefits the Player?

The removal of individual cards has a more pronounced effect in single deck blackjack than it does in multiple deck games. This results in several benefits for the player, starting with the increased likelihood of drawing an ace on a ten-value card and vice versa.

You can read more about blackjack probabilities further on in the guide. For now, it suffices to say the likelihood of getting a natural in a single deck game is higher at 4.83% as opposed to that in eight deck blackjack which is around 4.75%.

This works out to having a blackjack once every 20.71 hands when a single deck is in play. In games that utilize the full set of eight decks, you will get a blackjack only once every 21.07 hands on average. This difference, as small as it is, has its say in the long term due to the higher payouts blackjacks earn you.

Another benefit is that the dealer and player push with blackjacks less often in single deck games. If you have already pulled an Ace to a ten-value card, you reduce the Ace-richness of the deck by 25%. The probability of pushing with the dealer when you have a blackjack is roughly 3.67% when the game plays with one deck only. This percentage increases to 4.60% in eight-deck games.

In single deck games, the dealers have higher chances of breaking their hands which also works to the advantage of the player. Small cards like 4, 5, or 6 are good for the dealer so their chances of busting increase each time a small card leaves the pack.

### Why Single Deck Blackjack is Detrimental to the Player?

Unfortunately, casinos have successfully offset the value single deck blackjack gives to players by changing some of the most crucial rules of play. Each rule change gives the house an advantage but never the other way around.

The reduction of the payouts in blackjack itself yields a substantial house edge of around 1.40%. This is practically a total rip-off, which alone should suffice to dissuade a sharp player from joining a single deck table. The even-money payouts are just as bad but at least here you have a choice from accepting or declining this option.

To add insult to injury, dealers at single deck tables are often required to hit soft 17 which gives the house edge a boost of 0.22%. The restrictions on doubling down further increase the casino’s advantage (by 0.09% if you can double on two-card totals of 9 through 11 and by 0.18% when doubling is limited to starting hands of 10 and 11 only).

The absence of DAS (double after splitting) tips the scales in the casino’s favor by another 0.14%. All these tweaks to the rules boost the house edge on single deck blackjack from the humble 0.15% to nearly 2% at some tables.

Single Deck Blackjack – NetEnt
RTP 99.60%
Blackjack Payout 3 to 2
Dealer Hits Dealer hits on soft 17
Surrender No
Double Down On totals of 10 or 11 only
Splitting Allowed on any pair; After splitting Aces only one card is drawn
Insurance Yes
Insurance Payout 2 to 1

## Single Deck Blackjack – Should You Play It?

All these observations raise the question “Should you bother playing single deck blackjack at all?”. Well, the answer really depends on whether or not you can find a game with relatively decent rules. The optimal alternative is for you to play single deck blackjack with late surrender where the dealer stands on soft 17s, you can double on any two-card total, double after splitting, and can resplit to four hands.

We regret to say you will have a hard time finding a single deck table with such favorable rules, though. Good single deck blackjack variations are practically non-existent in landbased casinos these days. The best you can do is look for single deck tables with payouts of 3 to 2 on blackjacks. Under no circumstances should you accept reduced payouts of 6 to 5 – this is equal to pouring your money down the drain.

In a way, the online gambling industry has saved single deck blackjack from complete extinction. The game is available at multiple online casinos and although it still abides mostly by adjusted rules, at least the operators have the decency of offering players the standard 3-to-2 payouts for blackjacks. Anything less than that is worth neither your time nor your money.

Dan Colette

### Can the single-deck blackjack strategy be applied to blackjack versions with two or more decks?

While single-deck and double-deck blackjack share similar rules, it is best to know the optimal action on each hand, depending on the number of decks you play with. In both the single-deck and the multi-deck versions of the game of 21, the optimal move is to split 2-2 or 3-3 when the dealer shows between 2 and 7. In a single-deck blackjack variation, it is also advised to split 6-6 if the dealer reveals 7 and they have to hit on soft 17s.

For doubling down decisions, the number of decks used in the game is also extremely important. Playing with a single deck gives players bigger confidence as there are fewer cards with a value of 10 in the deck. That is why the strategy for single-deck blackjack is bolder, suggesting more cases when doubling down is the optimal decision. The strategy for single-deck blackjack advises opting for doubling won on 8 if the dealer shows a 5 or 6. Another move, which is considered advantageous only when playing a single-deck version, is doubling down on 11. As you can see, the strategy changes when you play with one deck compared to playing with multiple decks.

Dan Hector