# How Many Decks In Blackjack?

It seems like a simple question: how many decks in blackjack? Casual players may be surprised to find that there can be one, two, four, six or eight decks used in a game of blackjack. While friendly games of blackjack are usually only played with one deck of cards, when you step into a casino you will find double deck deals, alongside four, six and eight deck games. So, lets examine why that is and also how many decks are used in two of the most famous gambling cities, Atlantic City and Las Vegas.

## Why Do Casinos Use More Than One Deck?

In 1966 the brilliant mathematician, Edward Thorp, released his ground-breaking book ‘Beat The Dealer’. In this book, Thorp mathematically proved that players could use a points-based system to beat the house in blackjack. Gamblers across the world soon adopted Thorp’s system, including one of the most famous gamblers in history – Bill Benter.

Until the release of Thorp’s book, almost every casino in the world would only have offered single-deck blackjack. However, card counting with a single deck was not an incredibly intellectual task that required a computer-sized brain; thus, it was quite an accessible system and a danger for casinos.  Before long, as casino bosses started to see the profits get eaten into by teams of card counting gamblers, changes had to be made. Casinos would soon introduce multiple-deck games, change minimum bets and alter pay-outs to protect themselves from card counters. Whilst card counting is still possible with multiple decks, it does not offer as significant an opportunity to gamblers as in the single-deck games.

## How Blackjack Works in Atlantic City

Atlantic City has a particular set of rules that means that casinos need to be a little bit more wary of their players’ abilities. The rules in the city state that skilled players cannot be banned from playing in any casino. This means that if a casino suspects that a certain player is counting cards, they cannot ask them to leave. Therefore, the casinos have found other ways to protect themselves.

To do this, the casinos of Atlantic City almost exclusively use either six or eight decks. This is due to the fact that increasing the number of decks will slightly increase the house edge. This is illustrated in the table below:

Here we can see that the house edge in six or eight deck games is more than double of that in a single deck game. This is an important edge for the casinos of Atlantic City as they look to protect themselves against the sharper players.

Spanish 21 is also on offer more often in Atlantic City than in other gambling cities – however, this is not due to the generosity of the casinos! Again, the house edge in Spanish 21 is quite high – some believe it to be anywhere up to 4%. Expert players are only thought to bring the edge down to around 0.45%, but this will only happen for the most skilled players using a most robust strategy.

## How Many Decks Are Used in Vegas?

As you would expect, Las Vegas presents a huge variety of options for its visitors. If you look hard enough, you are going to find single and double deck games – although these are not very common. The most popular offerings will be the six or eight deck games, which you can find at almost any casino. You can even find single deck blackjack in Las Vegas in some of the most popular resorts.

However, the variety of games on offer will differ depending on your budget and on the casino. For example, the MGM Las Vegas will let you play almost any variety of blackjack. On offer is single, double, six and eight deck blackjack. Be warned though, the minimum bet will be different depending on the game you choose. Our guide below illustrates this for you:

What you may find surprising here is that the minimum bet for single-deck blackjack is \$15, the same as six-deck and considerably less than double-deck blackjack. How can this be the case when we are taught that less decks are better for players?  Well, the casino has done this by offering 5 to 6 pay out for natural blackjack rather than the standard 3 to 2 that is available on the other games. By doing this, the house can increase its edge from 0.25% up to 1.24%. This is why it’s vitally important to know which of the variations of blackjack you are playing before you start, otherwise a winning hand could still provoke disappointment!

If you are reading this then the likelihood is that your next game of blackjack is not going to be in Vegas or Atlantic City. More likely you are going to get dealt in at an online casino. So, how many decks in online blackjack? Again, the answer will vary depending on the type of game you play.

If you are on the virtual tables then you will most-likely be playing with a single deck. Why? Well, as the software “shuffles” the virtual deck after every hand, card-counting will offer minimal benefit. Live games, however, are a different story. In the live games you will have a live croupier who will deal you in. Card counting would then be possible in the same as in any land-based casino. This is why in online casinos have followed suit with their land-based cousins and introduced six or eight deck games as the standard in their live games.

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Tom Bogues has been working in the gambling industry since 2020. He has a keen interest in all aspects from industry, from the casino floor to industry regulations.

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