You don’t need to be a mathematical genius to work out your chances of drawing a specific card from single deck.
There’s 52 cards in the deck, so if you wanted to pull out the king of clubs you’d have a 1 in 52 chance of doing so – let’s round that to 2%, for sake of argument.
If you need a king, you know there’s four in the deck – giving a rough probability of 8%, while if you need a diamond of any number you know your chances are 13/52….or 25%.
But when you add multiple decks to a game, that’s when these calculations become somewhat more tricky – your betting decisions in multiple-deck versions of blackjack, for example, will also be different given that the dealer has a wider range of cards to work with.
The basic tenets of blackjack strategy remain the same – but the manner in which you bet on them, and the size of your stake relative to your bankroll, should change accordingly.
How Many Decks are Used in Blackjack?
The number of decks used in blackjack will range from one to eight.
On the casino floor, you may see the blackjack dealer using a device called a shoe – this can hold up to eight decks of cards at once, which has given rise to a number of different blackjack variants beyond the single deck version.
As far as online blackjack is concerned, you will typically be able to play games that use either one, four, six or eight decks of cards – this will be detailed in the information table attached to each game.
For live dealer blackjack, it’s likely that multiple decks – usually six or eight – will be handled by the dealer.
Why Do Casinos Use Multiple Decks in Blackjack?
There’s one very simple reason that casinos use multiple decks in blackjack: to increase their house edge by making life more difficult for the player.
By way of example, card counting is so much easier in single deck blackjack than it is multi-deck. The dealer will not shuffle the deck after each hand, which allows the player to make a mental note of which cards have been played and which, therefore, have not. Add multiple decks into the equation and that gymnastics of the mind becomes so much harder to stay on top of.
It’s interesting too that dealers won’t shuffle the cards anywhere near as much when dealing multi-decks from a shoe as opposed to a single deck by hand. Because card counting is so much harder, it’s an unwritten rule that multiple decks are shuffled fewer times per hour – this at least speeds up the action for players.
What are the Odds of Winning Blackjack with Multiple Decks?
Perhaps a better way to phrase this question is how does the house edge change when more decks are added to a blackjack game?
Assuming conditions that are helpful to the player, such as blackjack paying 3:2, dealer having to stand on 17 and the ability to double down after splitting, the house edge of single deck blackjack can be as low as 0.014%.
But that more than doubles when a second deck of cards is added into the mix, before the house edge increases significantly when multiple decks are played against:
- Four decks – 0.49% house edge
- Six decks – 0.55%
- Eight decks – 0.57%
So the average player, in the average session, will lose more hands in eight-deck blackjack than they will in single-deck blackjack. That’s not to say you can’t win at multi-deck blackjack, it’s just much more difficult to do so – the numbers make that an unavoidable fact.
But as with any variant of blackjack, you can increase your chances of winning by following the tenets of basic strategy, while a flat staking plan will also ensure you maximise your chances of winning – as opposed to progressive staking systems that can rack up sizable losses amid a streak of losing hands.
Should You Bet Differently in Multi-Deck Blackjack?
There’s plenty of resources online that show you how to play any combination of hole cards that you are dealt.
And what’s interesting is that these tactics will change based upon the number of decks that are in play – and especially when comparing single deck to multi-deck blackjack.
With weaker hands, you should look to hit more often and double down less – for the simple reason that there are more cards in the dealer’s shoe that can beat your below-par combinations.
There’s also some specific situations where percentage plays exist. In single deck blackjack, you may consider doubling down with a score of eleven even if the dealer’s upturned card is an ace. But in multi-deck blackjack, minimising your risk by hitting is the smart play given the dealer’s positional advantage.
For the most part, basic strategy doesn’t change all that much from single-deck blackjack to multi-deck games, although there are some subtle – and crucial – differences in how you play certain hands that will save you some losses in the long run.
Does the Number of Decks in Blackjack Matter?
As we’ve delved deeper into this article, hopefully you’ve learned about the key differences between single-deck blackjack and those with multiple decks.
Single deck is the better option for players. It has a lower house edge and enables players to make more ‘predictive’ decisions, i.e. it opens the door to card counting.
With each extra deck added, the house edge increases. Remember, the dealer acts second and so already has that advantage, and when more low and high-value cards are added there’s extra ways for them to make that count.
As far as online blackjack is concerned, there’s less of a consideration because the deck – whether one or eight – is shuffled after every hand and produces unpredictable results courtesy of the in-built random number generator anyway.
But if you are playing on the casino floor, try and get a seat at the single-deck blackjack table – your results should, according to probability theory, be far better.