How to Count Cards in Blackjack – Counting Cards 101

If you’d like to learn more about how to count cards in blackjack then you’re in the right place. Card counting is a technique used in blackjack to reduce the house edge and even swing the edge in favor of the player.

Although counting cards seems incredibly difficult at first glance, it’s easier than it appears. In this card counting 101 guide, we teach you how to count cards in blackjack like a seasoned expert and greatly improve your odds of winning at a blackjack table.

What is Card Counting?

Many people have a misconception about what card counting is as it’s believed that it requires remembering every card played and the order in which they were played. In reality, you don’t have to remember specific cards that have been dealt but instead have an idea of the value of the blackjack cards that remain in the shoe.

To answer the question “What does counting cards mean?”, we should look at where the concept began. In the 1960s, Edward O. Thorp developed the theory of how to count cards in blackjack. In his book Beat the Dealer, O. Thorp used a mathematical approach to the game and was able to prove that by keeping track of the high and low cards dealt, players could adjust their betting and playing strategy to give them an edge over the house.

How to Count Cards in Blackjack

The fundamentals of counting blackjack cards at a casino is using a points system where cards are assigned points based on their value.

There are several different card-counting strategies, but the simplest and most commonly used is the Hi-Lo system. In this system, cards are split into three categories and then assigned points of -1, 0, +1. By using this points system, card counters can get an idea of the number of high cards left in the deck.

This is important as high cards are good for players for several reasons, such as more split or double opportunities and a higher chance of blackjack. On the other hand, high cards are not good for dealers as they must hit on anything below 17, including stiff hands (12-16) and high cards increase the chances of them going bust.

Live Blackjack Online

Card Counting Basics

Now, we will run through the card counting basics step-by-step. It’s important to remember that this only works at land-based casinos or online casinos with blackjack that don’t shuffle the decks too often.

About 70% to 75% of the shoe being dealt is ideal for card counting, but it is possible with the shuffle being performed at 50%. Anything below this makes the effectiveness of card counting almost impossible.

Know the Blackjack Number Values & PointsKeep a Running CountCalculate the True CountAdjust Your Bets Based on the Count

Know the Blackjack Number Values & Points

The first thing you need to learn to count cards is the point system. Cards are split into three categories, namely high cards, low cards, and neutral cards. Cards in these categories are then assigned points. The three categories and points are as follows:

  • Low Cards: 2, 3, 4, 5, 6 have a +1 points value
  • Neutral Cards: 7, 8, 9 have a 0 points value
  • High Cards: 10, Jack, Queen, King, Ace have a -1 points value

Keep a Running Count

Now comes the actual card counting. For every card dealt you need to keep a running count using the points values from above.

For example, we have 2 low cards (5,3), so +2 count. There are also 4 neutral cards (9,7,8,8) that are worth zero points, so +2 +0 = +2. And finally, there are three high cards (J, K,10), so we subtract -3 from the count, which means +2 + 0 -3 = 0, so the running count is -1.

You then carry over the count to the next hand. So, let’s say the next hand has 6 low cards (2, 2, 2, 4, 5, 3) +6, 4 neutral cards (8, 9, 7, 7) +0, and 1 high card (J). The current running count would be -1 (from the previous hand) + 6 + 0 -1, and the current running count would be +4.

Calculate the True Count

In the past, blackjack was played with one standard 52-card deck, but in the 1960s, casinos started to play with multiple decks, mostly to counteract the rise in card counters. It’s common now for blackjack games to be played with between 4 and 8 decks, most often 6 or 8.

Because of this, we need to calculate the true count. To do this, you just divide the current running count by the number of decks being used.

So, if we take our running count of +4 from the previous step and we are playing at a table using 4 decks, we would do 4/4, which equals 1. So, our true count is + 1. If 8 decks were being used, we would have 4/8, so the true count would be +0.5.

Adjust Your Bets Based on the Count

The next step in card counting is to adjust your bet size depending on the true count. As the true count increases, you should increase your bet. The higher the count, the higher your bet size should be. You should be betting small amounts when the count is negative or below 1.

A good way to do this is to set betting units before you start playing. Betting units help you effectively change your bets depending on the current count. However, the structured nature of this betting does make it easier for casinos to spot card counters. Here is a guide on the number of betting units to bet depending on the count.

  • Count of 0.9 or lower: 1 unit
  • Count of +1:1-2 units
  • Count of +2: 2-3 units
  • Count of +3: 4-5 units
  • Count of +4 or more: 6-10 units, depending on your bankroll

Basic Strategy Card Counting Explained

Once you’ve mastered how to count cards in blackjack, you need to understand and implement some deviations from blackjack’s basic strategy. This will help push the odds further in your favor and give you the best chance of making a profit.

If the true count is +3, the optimal card-counting strategy dictates you should make these changes to your strategy.

  • Buy insurance on a dealer’s Ace as the likelihood of them having blackjack is increased.
  • Double down on 10 against a dealer’s Ace
  • Double down on 9 against the dealer’s 7
  • Split 10s instead of standing
  • Stand on 16 against a dealer’s 10

Hi Lo System

There are several different ways to count cards in blackjack, all of which use a point system but assign points slightly differently. One of the most effective and simple systems is the Hi-Lo system, and this is the system we used in our step-by-step guide.

As you saw earlier, this system assigns -1 points to cards 10 through Ace. 0 points for neutral cards 7 through 9, and +1 points to low cards 2 through 6. When the count is at +1 or more, this is when the ratio of high cards in the deck is in favor of the player, so bets should increase the higher the count, the more you should bet.

Running Count vs True Count

A comprehension of the distinction between the running count and true count is fundamental in card counting, and mistakes in either totally eradicate any advantage a player has over the house. Below, we explain exactly what the difference is between these two terms.

Running Count

The running count is the cumulative total of the total card value according to the points system. So, if 20 low cards (+20) have been dealt, 10 neutral (0), and 14 high cards (-14) dealt, the true count is +6. The running count and true count start from the first hand dealt after a reshuffle until the deck is reshuffled.

True Count

The true count is the running count that is adjusted for the number of decks being used. Most blackjack games now use multiple decks, usually 6 to 8. You can work out the true count by dividing the running count by the number of decks in use.

The information will only be accurate if you use a running count in a game played with multiple decks. If you forget to convert a running count of +6 in a game played with 6 decks, you will be wildly overbetting and are statistically likely to make some big losses.

Card Counting Tips

Now that you know the basics, here are some top card-counting tips to boost your gameplay to its maximum potential.

Tip #1: Learn Basic Strategy for Card Counting

The first thing you need to do before card counting is have a concrete understanding of how to play blackjack and basic blackjack strategy.

Once you’ve mastered this and are proficient in keeping a running and true count, you need to learn the deviations from basic strategy when card counting. While counting cards and adjusting bet size is a big part of improving your edge, using the specific card counting deviations from the basic strategy will maximize your advantage over the casino.

Tip #2: Take it Slow

Newcomers to card counting shouldn’t just jump straight into playing for real money after practicing at home with packs of cards. You should utilize free card counting software from the internet and practice at home before risking money.

Also, once you are ready to put some money on the line, start with low stakes. Online live casinos are ideal for this, as you can find tables with minimum limits below $1, which allows you to make mistakes without losing big. In addition, take advantage of casino bonuses, as you can win real money without the risk of losing your hard-earned cash.

Tip #3: Only Play at Live Tables Online

By reading our card counting guide, you should now know that card counting will not work at RNG tables. This is because most RNG table games use a single deck but reshuffle the deck after each hand. This makes it impossible to card count.

The ideal place to card count is at brick-and-mortar casinos, but you can also do it online at live dealer tables as long as the deck is shuffled after at least 50%, but ideally, when roughly 70% to 75% of the shoe has been dealt. The best blackjack casinos offer multiple live tables with huge betting limits, making them perfect for rookie and professional card counters.

Tip #4: Don’t Waste Your Time at 6/5 Blackjack Tables

Traditionally, blackjack pays out at 3/2, but several casinos have changed the payout to 6/5. This may not seem like a big difference, but a 3/2 blackjack payout table has a house edge of around 0.5% with a basic strategy. With card counting, players can cut this edge by about 0.5-2%, giving them the edge.

A 6/5 payout increases that house edge to around 1.85% with basic strategy. Even with the advantage of card counting, players are still at a disadvantage or, at best, have a minuscule edge over the house, so you should exclusively play on blackjack apps and casino sites that offer a 3/2 payout.

Tip #5: Use Betting Units

As mentioned earlier in our “How to card count section”, when counting cards, it is best to bet in units rather than dollar amounts. Before betting, work at your minimum bet amount, and this is your betting unit.

This makes it easier to adjust your betting when the count dictates, so rather than saying you need to bet this extra amount of dollars you can simply say it’s now time to bet 3 units. It’s also an effective blackjack bankroll management tool, which is essential when counting cards.

Inaccuracies of Counting Cards

While card counting for blackjack is a powerful tool, it’s not the guaranteed money-making scheme often portrayed in the media. It has several inaccuracies and limitations.

Firstly, there’s plenty of room for human error as keeping track of the card count in blackjack requires you to pay close attention straight from when the first cards are dealt from a newly shuffled shoe. If there are several people at the table, this is difficult, especially with the many possible distractions in a casino. You also have to remember to correctly bet according to basic counting cards strategies and covert running count to true count, which further complicates things.

Deck penetration is also important. Optimal card counting is done when about 70% to 75% of the deck has been played before a reshuffle. Furthermore, the system requires you to view several hands before becoming effective, and it gives just an approximation of the cards in the deck. Even if you do everything perfectly, you will not make a profit in every session, so be prepared to lose sometimes.

Blackjack Card

Is Counting Blackjack Cards Allowed?

Card counting is completely legal, and if you are caught card counting in blackjack, you won’t face any legal action. However, if casinos do suspect you of counting cards, you will almost certainly be backed off.

A backoff in blackjack means, at best, having your bet limit limited to the minimum table limit. However, more often than not, you will be banned from playing blackjack or even banned from that casino or site. In most cases, your info will be passed to other casinos in the area or to sister sites online, and you will be prevented from playing in these establishments before you even start.

Casinos are also legally allowed to do this as they are private establishments and can refuse service to anyone as long as it’s not based on race, gender, sexual orientation, etc. Whatever money you manage to make before getting kicked out or banned, though, is legally yours, and casinos have to cash out your winnings.

Where to Try Out Card Counting

Now you know how to count cards in blackjack, you’ll want to know where to try it. The best online casinos to use are those that offer live dealer tables.

There are several online sites that provide live tables, but in our opinion, Wild Casino is the best website to use your newly acquired blackjack card counting strategy. It has over 20 live dealer blackjack tables with limits ranging from $5-$50,000 and some very generous bonuses.

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Other Useful Articles On ReadWrite

Players shouldn’t attempt to count cards before being familiar with the game. This should be the last step in maximizing your winning potential and we recommend reading up on other blackjack strategies before deciding to opt for counting cards. So, to help you out, we’ve put together a few useful articles about popular systems players use in blackjack.

FAQ

What is the easiest way to count cards in blackjack?

Can you legally count cards in blackjack?

What is the math behind counting cards in blackjack?

Is it profitable to count cards in blackjack?

Responsible Gambling

Gambling addiction can have profound negative effects on people’s mental well-being and financial security. It’s essential to always practice responsible gambling when playing blackjack and taking part in any form of gambling. It’s also important to seek professional help if you believe you or someone you are close to has a gambling problem.

Resources

About ReadWrite’s Editorial Process

The ReadWrite Editorial policy involves closely monitoring the tech industry for major developments, new product launches, AI breakthroughs, video game releases and other newsworthy events. Editors assign relevant stories to staff writers or freelance contributors with expertise in each particular topic area. Before publication, articles go through a rigorous round of editing for accuracy, clarity, and to ensure adherence to ReadWrite's style guidelines.

Joe Yarnold
Editor

Joe Yarnold joined the ReadWrite team in 2024 as a content editor and writer. He has experience writing informative and educational articles on gambling. You can find his articles across multiple sites including Basketball Insiders and SportsLens. He specializes in sports betting but has experience, and knowledge of all forms of gambling including casino games, poker, and horse racing.

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