Blackjack strategy 101: Double-deck v single-deck
There are subtle differences between a game with a single deck and one with multiple decks. Our handy guide explains some of the key ones.
Online blackjack is one of the easiest games to learn.
The beauty of playing blackjack online is the huge range of variants with different bets and odds.
In 2018, it's possible to play classic blackjack with up to 8 decks or a single-deck blackjack variant with just 52 cards.
With players able to choose between single deck and multi-deck blackjack online, which one should you go for, and which games offer the best chances of winning? Let's explore these two popular blackjack games to find out.
How to play blackjack
In the early days of casino games, blackjack was played with just a single deck. Card counters could quickly pick up how many high value cards were left in the deck.
Over time, casinos began including more and more decks. Automatic shufflers kept the cards random and made it harder for card counters to work out what was going to come out.
Having so many decks in the shoe also made the house edge slightly higher. Players would be more likely to bust (go over 21 with their hand) and lose more in the long term.
The rules of single-deck and multi-deck blackjack are actually the same: players get dealt two cards each, with the dealer getting one up and one down.
Players must then decide whether to receive more cards (hit) and try to get as close to 21 without going over. The player can also stand (receive no more further cards).
Once the player has had their turn, the dealer takes cards. The hand closest to 21 – without going over – wins.
In both forms of the game, a blackjack (an ace with a picture card worth 10) pays 3/2, although it's not uncommon to find single-deck blackjack variants paying just 6/5.
Beating the dealer's hand pays 1/1 in both variations.
Different strategies when playing single deck and multi-deck
The key differences when gambling on single-deck and multi-deck blackjack are in knowing what to play, when.
Most importantly, you need to know when to hit, stand, or double down.
In both games, it's optimal to split 2-2 and 3-3 if the dealer shows 2-7 face up.
In single deck you can also split 6-6 if the dealer shows 7 and they have to hit on a soft 17 (a 17 containing an ace that counts as 1 or 11).
Hit/Stand: single deck vs multi-deck cheat sheet
The double down is a bet where players double their wager and receive one more card only.
There are a few more double down moves in single-deck blackjack.
As there are fewer cards with a value of 10, it's harder for the player to bust their hand.
In multi-deck blackjack, where you can have up to 8 decks, there are simply more 10-value cards to hit.
As you can see from the table, in single-deck you can even double down on 8 if the dealer shows a 5 or 6. With such a low up card, the dealer will find it harder to make a winning total.
Doubling down on 11 in single deck is a more advantageous move too.
In regular multi-deck blackjack it's advisable to just hit in case the dealer hits his blackjack and the hand is tied.
Advantages and disadvantages of single-deck and multi-deck blackjack
The bonus of single-deck blackjack is that it's easier to keep track of what cards have come out of the deck.
However, the house edge is higher on the insurance bet (5.9 per cent) as there are fewer 10-value cards in the deck.
Multi-deck blackjack is more widely available online and it's slightly easier to double down given the higher number of 10s and picture cards.
When playing optimal strategy, multi-deck blackjack also boasts a slightly lower house edge than its single deck cousin.