How to Count Cards in Blackjack – A Complete Guide for Beginners

The main principle behind card counting in blackjack is that a deck filled with 10-value cards is better for the player. Conversely, a deck filled with low-ranking cards is better for the dealer.

The idea is to keep track of which cards are played and then adjust your betting accordingly. For instance, if you count that the remaining shoe has a lot of 10-value cards left, you can increase your stake in order to win more. However, if the odds are against you, you lower your betting and wait for a better opportunity.

The question of why high-value cards are better in blackjack is fairly complicated. Suffice it to say that such cards contribute towards better hands for players – you can only get a Natural with an Ace and a 10-value card, for instance. Moreover, dealers in blackjack are forced to Hit even if their hands total 12-16, so 10-value cards increase the likelihood of a dealer bust.

Of course, card counting is a relatively advanced strategy. Knowing when you have an advantage and how to use it is not easy. As such, only recommend that you only continue with this guide if you’re comfortable with the basics of blackjack. If not, you can check out our blackjack tutorial to learn the ropes. We also recommend reading our guide to blackjack card values so that you can more easily understand why some cards are better than others.

Also, card counting relies on adjusting your basic strategy based on which cards are left in the shoe. As such, you should at least be familiar with what basic blackjack strategy charts are. If you’re not, this guide will give you a handy introduction.

The history of blackjack card counting dates back to 1962 and the book Beat the Dealer by American mathematician Edward O. Thorp. However, much of the history of blackjack after the ’60s is ’70s is about how casinos adjusted the game’s rules to counteract player strategies like card counting. As such, many of the original principles no longer apply.

That’s why new techniques were developed by pros and teams such as the famous MIT blackjack team. Casinos kept changing things to stop players, while players kept developing new strategies to beat the casinos.

Our point is that card counting is not an exact step-by-step process but a collection of systems and techniques that all rely on the same mathematical principles. The rest of this guide will go through some of the most common and beginner-friendly card-counting techniques and systems, offering you some options in terms of how you want to approach the game.

Basics of Card Counting

Now that we’ve covered the broad strokes, it’s time to get into the actual strategy. The best way to understand card counting is to see how it works in practice. As such, we’ll get right into the oldest and arguably simplest card-counting system out there – the Hi-Lo.

The Hi-Lo System

The Hi-Lo system for counting cards in blackjack is one of the oldest and most studied counting systems. It dates back to 1963 and the mathematician Harvey Dubner, but has been used and examined by countless respected pros and writers.

The Hi-Lo, or High-Low blackjack card counting strategy is all about tracking the remaining number of high-value cards in the shoe.

To do this, we start by assigning values to every card based on their rank. We use these values to keep track of which cards are played through and which are still in the shoe.

Assigning values for Hi-Lo is quite simple:

• 2-6: +1
• 7, 8, 9: 0
• 10, J, Q, K, A: -1

In other words, low-rank cards such as 2s and 3s add +1 to your count. 10-value cards and Aces subtract -1 from the count, while middle-rank cards keep the count where it is.

Assigning these values allows you to track which cards are played through much more easily than if you were to track each card individually. This gives you insight into which cards are left in the shoe and how good the shoe is for you as a player.

Running Count

The running count, or simply count, refers to the process of tracking which cards are dealt and which are still in the shoe. Instead of tracking every card rank individually, we simply keep a running count of the card values we assigned in the previous step.

Keeping a running count is all about paying attention to which cards are dealt and keeping a “score” of their values. Here’s how that works.

• The count starts at 0 when the dealer shuffles and starts a new card shoe.
• As cards are revealed, add and subtract from it based on the values you assigned.
• Every card ranked 2-6 adds +1 to the count
• Every 10-value card subtracts -1 from the count
• 7s, 8s, and 9s do not affect the count

Think of it this way – if a 10-value card is dealt and played, it means that there are fewer 10-value cards left to play in the shoe. This also means that there are relatively more lower-value cards left.

Based on what we already covered, the conclusion is simple: the higher the running count, the better the remaining cards are for the player because it means there are more “good” cards left in the shoe.

A higher running count means you should increase your stake, while a low count means you should decrease it as much as possible. We’ll get into the details a bit later.

For now, let’s illustrate with an example.

Let’s say that the first 10 cards to be dealt during the first round are 4, K, 9, 10, 3, 5, A, 6, 8, and Q. In this case, calculating the running count would look like this:

1 – 1 + 0 – 1 +1 + 1 – 1 + 1 + 0 = +1

It’s a relatively simple system, but it takes some practice to keep a reliable count despite how fast or hectic the action might be. Experienced counters are able to calculate a running count in a matter of seconds merely by glancing at the table.

True Count

If you’re thinking that things are a bit too easy, it’s because we’re only scratching the surface.

As we already mentioned, casinos implemented various rule changes to counteract card counting. One of these changes involved introducing multiple decks into blackjack. Until the 70s all blackjack tables only used one deck, which proved way too easy to count.

Counting cards in blackjack is less informative and less useful if the shoe contains multiple decks. It makes sense, really – more cards in the shoe mean that you learn less about it as cards are played through. As such, you need to account for the total number of decks while counting cards. This brings us to a concept known as the “true count”.

In card counting, the true count refers to your running count after it has been adjusted for the number of decks in the shoe.

To find out your true count, you simply have to divide the running count by the number of decks in the shoe.

For example, let’s say you’re playing a relatively new shoe at a table that starts with 6 decks per shoe. If your running count is +6, you need to divide it by 6 to get the “true count”: 1.

Things can get a lot more complicated here because the total number of cards left in the shoe changes as the game progresses. After a few rounds of the 6-deck game, there will only be cards for around 4 decks left. If that’s the case, you need to divide your running count by 4 rather than 6.

Again, knowing how many cards are left in the shoe takes some practice. You don’t have to be exact here, and you don’t literally have to count out every card that’s revealed. “Eyeballing” is good enough for most players. In other words, you should just try to roughly estimate. While this may give you the wrong true count, the cases in which that actually matters are incredibly rare.

Adjusting Your Strategy Based on the Count

The real meat of card counting is not actually keeping track of the cards. It’s how this information is used to adjust your strategy.

As we already mentioned, this comes down to the idea that a higher true count means that the shoe is better for the player. You can take advantage of a high count in two ways: increasing stakes or adjusting your playing strategy.

Adjusting Stake Levels

One way to use this advantage is to simply increase the stakes.

There are no rigid rules as to when and how much you should do so. The higher the true count, the more you should raise the stakes. Conversely, if the count is 0 or lower, you should make the minimum bet you can.

The most common approach to this adjustment is to create a “bet spread.” This means that you should set the minimum stake you’ll be using when the count is low (typically, this is the table minimum) as well as a maximum stake you’ll use when the count is at +6 or more. The maximum depends on your bankroll and how much you’re willing to risk.

Most bet spreads start increasing stakes once the true count reaches +2. A common approach is to double the stake at +2, triple it at +3, and so on.

This can seem a bit abstract, but there’s a reason we’re not giving you exact instructions. There are pre-set blackjack bet spreads out there, but they tend to be common patterns that have been around for decades. These patterns are easily spotted by trained casino staff, meaning it’s easy to get caught if you use a pre-made bet spread.

Adjusting Playing Strategy

The other way to take advantage of the count is to adjust your playing strategy. A lower count means that you’re more likely to win hands than you are otherwise, which means that you should make some decisions that you otherwise wouldn’t.

This is where knowledge of basic blackjack strategy charts comes in handy. Blackjack charts give you exact instructions on the optimal way to play every possible hand in blackjack. However, the “optimal way” changes based on which cards are left in the shoe.

In other words, the idea is to deviate from basic blackjack strategy because the running count tells you that it’s advantageous to do so.

There are many strategies and systems for adjusting bets while counting cards in blackjack. However, we’ll present you with a simple one called “Illustrious 18”. It was developed and presented in the book Blackjack Attack by Don Schlesinger.

The system offers a set of “index numbers” and instructions for how they affect basic strategy. It presents you with a range of hands and situations you might find yourself in.

If the current true count equals or exceeds the index number, you should stand, split, or double. If the count is lower, you should Hit instead.

Step-by-Step Guide to Counting Cards

Let’s sum up everything we’ve learned by going through the required steps of card counting again.

The system we’ll be referring to is Hi-Lo or High-Low. There are other systems out there, but they all use the same underlying principles. Other systems change details such as how valuable each card is and how the count should affect your strategy, but they all have the same basic steps.

• Step 1: Assign Values to Cards – In the Hi-Lo system, cards ranked 2-6 have a value of +1, cards ranked 10 and up have a value of -1, and other cards have a value of 0.
• Step 2: Keep a Running Count – Add and subtract the assigned values from the count based on which cards are played through.
• Step 3: Calculate the True Count – Divide your Running Count by the approximate number of decks left in the shoe.
• Step 4: Adjust Strategy – Whenever the True Count is high and thus favourable, adjust your playing in two ways:
  • Increase the stakes – Whenever the True Count is at +2 or more, increase the stakes. The higher the True Count, the more you should increase the bet.
  • Deviate from basic blackjack strategy – A high True Count also means you should make different decisions in specific circumstances.

Practicing Card Counting

Breaking down card counting makes it seem incredibly easy, but actually counting cards in a real-life casino is a much more complicated matter.

First of all, keeping a correct true count going can be more difficult than it seems. You have to keep in mind that there will probably be multiple people at the table. This means more cards to track and more variables to consider. Additionally, skilled dealers handle cards with a lot of speed and grace, too, giving you less time to count them. On top of that, you have to think about how the count affects your strategy and adjust accordingly, and you have to do it all on the spot.

The best way to ensure you can reliably keep a True Count and adjust your bets is through practice. Here are some tips for practising card counting without risking your money:

• Count through decks of cards – Simply run through a deck of cards while counting them based on Hi-Lo values. Eventually, you’ll start to see cards as 1s, 0s, and -1s. As you get better, you can increase the number of decks and practice maintaining a True Count as well.
• Simulate a live game of blackjack – Set up your own blackjack game where you’ll be acting as both the dealer and all the players. The idea here is to practice your ability to quickly count cards separated into different hands in a realistic scenario. Focus on maintaining a True Count instead of playing “correctly.”
• Use online simulators or drill apps – If you don’t have the cards or patience to practice with real cards, drill apps can be a great solution. The Counting Training Drill app from Blackjack Apprenticeship is an easy recommendation. You can also find more useful blackjack software here.
• Back Counting – Back-counting simply means counting cards at a blackjack table without actually playing on it – you just stand behind other players and pay attention. It can be a way to practice counting with no risk or a strategy for concealing your count from the casino staff.

Legality and Casino Countermeasures

The most common question surrounding this blackjack strategy is always the same: is card counting legal?

In short, yes – card counting is legal in most of the world. This depends on where you live, of course, but most countries in the world consider card counting to be a legal, legitimate way of strategically playing blackjack. For instance, it’s legal in Britain and every US state. In fact, casinos in Atlantic City are prohibited from banning card counters as a result of a New Jersey Supreme Court ruling.

Moreover, carting cards in blackjack is decidedly not cheating. Nothing you do while counting cards breaks any of the rules of the game or of the casino. After all, the strategy simply relies on tracking cards to help you spot an advantage. This is a widely accepted (and encouraged) practice in pretty much every card game, even if the casinos try to tell us otherwise.

However, casinos still object to card counting. Most casinos and gambling venues reserve the right to deny service to players and can outright ban you from the premises if they suspect you’re counting cards. In other words, if you get caught, the casino will ban you from their blackjack tables.

Casino staff, including dealers and pit bosses, are trained to spot certain patterns associated with card counting. The most obvious pattern is increasing bets whenever the count is high, but there are other “tells” such as skipping rounds or frequent table changes. Many casinos simply ban players who win too much in blackjack, too.

As a result, there has been an ongoing “battle” between casinos and card counters. In their attempts at countering card counters, casinos have implemented a variety of measures such as:

• Increasing the number of decks
• Decreasing deck penetration (the portion of the shoe that is played before being shuffled)
• Surveillance personnel
• Video surveillance
• Maintaining databases of advantage players

Some of these countermeasures have caused a lot of controversy over the years, such as the one about maintaining player databases.

Either way, the conclusion is simple: card counting is legal, but casinos will do everything in their power to keep you from doing it anyway.

Avoiding Detection

With all of that in mind, being able to count cards without the casino realizing what you’re doing is a major concern. In fact, practised card counters focus more on avoiding detection than the actual count.

Avoiding detection while counting cards is no simple matter. It can depend on the casino you’re playing at, the countermeasures it deploys, and various other factors. Here are some general tips that can help you keep the pit bosses at bay:

• Intentionally make bad decisions – According to casino staff, more than 90% of players don’t even follow basic blackjack strategy. Doing so is a dead giveaway that you’re at least semi-competent. Consider intentionally making decisions that conflict with your blackjack chart now and then just to seem less skilled than you really are.
• Make occasional side bets – Similarly, blackjack side bets are universally worse than the main bet. Making side bets every now and then tells the staff that you don’t really know how RTP works because you’re making bets with a high house advantage.
• Don’t bet too aggressively – Fluctuating stake levels are another card-counting giveaway. That’s why many counters increase stakes at a curve or refrain from increasing them every time there’s a positive count. It’s better to lose an opportunity or two than get banned from the casino.
• Mask your stake adjustments – Instead of limiting your stake changes, you can also try to behave like the reason you’re changing the stake is more “natural.” For example, you can try only increasing stakes after a winning hand or decreasing them after a loss. This simulates common player behaviour, hopefully masking the real reason you’re playing the way you are.
• Play with ‘teammates’ – Playing in teams is a common method for card counting because it allows you to throw off the pit bosses by splitting tasks. For example, one player can sit and repeatedly play minimum wagers while maintaining a count. Once the count is high enough, they signal a different player who comes in at plays with significantly higher stakes.