Blackjack Card Counting: The Ultimate Strategy & Tips

Even if you don’t know how blackjack card counting works, we bet you have definitely heard of this advanced strategy before!

It’s been made famous by countless movies and television shows, most notably, 21 (2008) which tells a slightly dramatised version of how the MIT Blackjack Team used card counting to take on Las Vegas casinos throughout the second half of the 20th century. 

Even if you haven’t seen that one, card counting is featured in The Hangover (2009), Rain Man (1998), Passionada (2002), and Animal World (2018). 

So, you’ve seen it work on screen. But have you ever wondered how it actually works or whether you could do it yourself here in New Zealand? Let’s take a look.

What is Blackjack Card Counting?

Card counting is just one of many different strategies used by blackjack players to try and reduce or remove the house edge. 

Unlike other tools that a blackjack player might use, such as basic strategy and perfect strategy, blackjack counting cards requires you to do a bit of extra work. 

While basic and perfect strategy focus on whether to hit or stand in every possible combination, card counting can help you to understand the likelihood of high or low cards being drawn from the shoe. 

Combined with basic strategy, this allows you to vary your bet sizes to maximise the times when the deck is stronger. 

Sounds complicated? That’s because it is. 

Is it Even Legal to Count Cards?

Before we look at how card counting blackjack works, let’s address an important question – is it legal to count cards?

Yes, it’s completely legal to count cards in New Zealand and most other parts of the world. Provided you are doing the number crunching in your head and you’re not using any devices to help you, then you’re in the clear. 

How Does Blackjack Card Counting Work?

As its name suggests, card counting in blackjack involves counting the cards that come out of the shoe.

You’re not simply adding up how many cards you see, though. You’re tasked with assigning a value to each card and then adding and subtracting those values to form a “running count”. It is only basic arithmetic, but you need to do it quickly and constantly throughout the game. 

Essentially, there are four steps to counting cards:

1. Assign values to the cards
2. Using those values to keep a total in your head (this is known as the “running count”
3. Convert this into the “true count”
4. Increase your bet size as this true count rises and reduce it as it falls

The exact approach varies depending on whether you are playing blackjack with a single deck or several in the shoe. The basics remain the same, but there is a little extra work involved for multi-deck games.

Card Counting With One Deck

The process of counting cards with just one deck is a little simpler. Firstly, you need to assign a value to the cards, these are:

• 2-6 = +1
• 7-9 = 0
• 10, picture cards, and ace = -1

You start at zero and then use these values to calculate your running count. So if you see a two, four, eight, and 10 drawn, the calculation would be:

0 + 1 +1 + 0 -1 = 1

This means that the running count after these four cards is +1. 

As the count rises, you should increase your bet sizes. This is because a higher count indicates that there are fewer lower-valued cards left in the deck, increasing the likelihood that you could get blackjack or a similarly-high hand. 

Card Counting With Multiple Decks

Most blackjack games found in casinos today use multiple decks in the shoe. This makes card counting more difficult because it increases the number of aces and 10s that can be drawn. 

In a single-deck game, as soon as you’ve seen four ace cards, you know that it’s impossible for you or the dealer to have blackjack. 

But when there are several decks, seeing four aces might have reduced the odds of blackjack, but it most certainly is not a zero chance. 

This is why advanced blackjack card counting involves turning the running count into the true count 

To do this, you must divide the running count by the number of decks in the shoe. So if you think there are five decks and the count is currently +5, you would divide +5 by five to get a true count of +1. 

However, you may not always know how many decks are in the shoe. In this case, you can try asking the dealer or you can estimate. 

Is it Possible to Count Cards in Online Blackjack?

Yes and no. The effectiveness of online blackjack card counting depends on the game you choose to play. 

Most online blackjack games use continuous shuffling which essentially reshuffles the cards in the shoe after every round of dealing. This reduces the effectiveness of card counting. 

Continuous shuffling machines may not be used on live dealer games, so this could make your card counting more effective. However, the dealer still often shuffles the deck manually every few hands. 

Despite this, card counting online blackjack may still be useful for you if you want to use it to practice before heading to a land-based casino or casino online. 

Verdict: Should You Count Cards?

Counting cards can be an effective way to reduce the house edge in blackjack. However, it is not as simple as it may appear in the movies. 

Sure, blackjack card counting only requires you to add and subtract one each time, but it’s still mentally taxing. You will also need to do some division to convert the running count to the true count in multi-hand games. 

If you want to add a new challenge to your blackjack playing, then counting cards is definitely a viable way to do this. But it’s important to understand it’s not a tool to guarantee you’ll win.