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Learning how to count cards is one of the only legitimate ways a player can gain an edge over the casino. While it may seem intimidating at first, the basics are surprisingly simple.
In this Card Counting 101 guide, you’ll learn how to count cards in blackjack step by step, boost your odds, and play smarter. We’ll also cover the laws around card counting, common myths, and practical tips to help you succeed at the tables.
What is Card Counting?
Many people have a misconception about what card counting is, and wrongly think 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, and +1. By using this point system, card counters can get an idea of the number of high cards left in the deck.
This matters because high cards benefit the player in several ways; they increase the chances of getting a blackjack, and they create more opportunities to double down or split. For the dealer, however, high cards are a disadvantage. Since they must hit on hands below 17, high cards raise the risk of busting, especially with stiff hands like 12–16.
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 & 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 Blackjack Strategy
The first thing every blackjack player should master is basic strategy, a chart that outlines the statistically best move based on your hand and the dealer’s upcard. Using basic strategy alone (without card counting) significantly improves your odds, though the house still retains a slight edge.
The chart below shows the optimal plays for standard blackjack. When counting cards, you follow the same chart with a few adjustments, which we’ll cover in the next section.
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 that 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
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, which 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
Once you’ve mastered the basics, the next step is to learn how to count cards in blackjack with multiple decks, since most casinos use 6 or 8 decks. Understanding the difference between the running count and the actual count is essential. Confusing the two or miscalculating either can completely eliminate any edge you’ve gained. Below, we break down exactly how these two concepts differ.
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.
Black Card Counting Practice
Now you’ve learned how to count cards in blackjack, let’s put it to the test. Below are 10 hands of blackjack. Try to work out the running count and the true count if there are two decks in play, and then check your answer below the table:
| Hand # | Player Cards | Dealer Cards |
|---|---|---|
| 1 | 8♦, 3♣ | 10♥, 5♠ |
| 2 | Q♦, 6♠ | 2♥, 9♣ |
| 3 | 7♥, 2♣ | K♠, 4♦ |
| 4 | 5♣, 9♠ | 3♥, 6♦ |
| 5 | A♠, 7♦ | 8♠, 10♦ |
| 6 | 4♣, Q♣ | J♠, 2♠ |
| 7 | 5♦, 3♠ | 6♣, K♦ |
| 8 | 9♦, 8♣ | A♦, 4♠ |
| 9 | 2♦, 10♠ | 5♠, 7♠ |
| 10 | J♦, 6♥ | 9♥, 3♦ |
Card Counting Tips
Now that you know the basics, here are some top card-counting tips to boost your gameplay to its maximum potential.
Inaccuracies of Counting Cards
While card counting in blackjack can shift the odds slightly in your favor, it’s far from a guaranteed way to make money, and it’s certainly not the “golden goose” it’s often made out to be in movies and the media. There are several challenges and limitations that reduce its overall effectiveness.
First, card counting requires significant practice and concentration. It’s not easy to maintain an accurate count, especially in a busy casino environment filled with noise, distractions, and conversations at the table. Beyond tracking the running count, you also need to constantly convert it into the true count, which adds another layer of complexity and increases the risk of errors.
Deck penetration is another crucial factor. Card counting is most effective when about 70% to 75% of the cards have been dealt before the deck is reshuffled, and many casinos now (especially online) will shuffle the deck before this point. Additionally, the system relies on observing several hands before it becomes useful, and even then, it only provides an estimate, not a precise picture, of the remaining cards.
Even if you execute everything flawlessly, the advantage you gain is relatively small, typically around 1% to 2% over the house. This means variance still plays a significant role, and there will be plenty of sessions where you walk away with a loss despite playing perfectly.
Is Counting Blackjack Cards Allowed?
Card counting is entirely legal, and if you are caught card counting in blackjack, you won’t face any legal action. However, if casinos 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 (in most states) 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.
Know Your Rights
Card counting isn’t illegal, but many casino employees and law enforcement have a misunderstanding of the law. If you’re serious about counting cards, it’s essential to understand the laws surrounding the matter and know your rights:
You Can’t be Arrested for Card Counting
While some card counters have been detained, none have been charged because card counting is not illegal. If you’re arrested, contact a lawyer immediately; in most cases, they can resolve it quickly. You may also have grounds for legal action against the police for unlawful arrest. If a casino detains you against your will while waiting for authorities, you may have a case against them as well.
Cashing Out
A casino cannot legally refuse to cash you out simply for card counting. If this happens, report the incident to the gaming commission. If card counting is the sole reason for the refusal, the commission will typically force the casino to pay.
Identification
Casinos often request ID from suspected card counters when cashing out, claiming it’s policy or required by law. In reality, ID is only legally required for transactions over $10,000. You’re within your rights to refuse.
However, a casino has the legal right to deny you access if you decline to provide ID if requested upon entering, but if they allow you to play, then by law, they must let you cash out under $10,000 without providing ID.
Getting Banned
In most states, a casino can ban you if it thinks you are counting cards. However, in New Jersey, Louisiana, and Missouri, casinos are not allowed to ban players just for counting cards. While they can’t ban you, they can change your betting limits.
Trespassing
As mentioned, casinos in most states can ban you for virtually any reason, including card counting. In many cases, they’ll also issue a formal trespass notice. Once that’s issued, you are legally prohibited from returning to the property. If you do, you risk being arrested and charged with trespassing.
Tribal Casinos: A Different Set of Rules
Everything discussed so far applies to state-regulated casinos. Tribal casinos operate on sovereign land and follow their own laws, enforced by tribal police and overseen by tribal gaming commissions. While this doesn’t mean they can act without accountability, it does make it harder to determine your exact rights.
If you’re backed off or refused a cashout, the best approach is to take your chips and either have someone else redeem them later or contact the local tribal gaming commission for guidance.
Where to Try Out Card Counting
Playing in person is the best way to count cards, but when you are just starting out on your journey, playing online is a good way to practise, as you can play for much smaller stakes. The best online casinos offer several live tables, and minimum bets are generally lower than in brick-and-mortar casinos.
While there are several solid options, we recommend Betwhale as the best site to put your newly acquired blackjack card counting strategy. It offers generous bonuses and over 20 live blackjack tables. There are also 20+ RNG tables, not suitable for card counting, but perfect for beginners to practice basic strategy.
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.
