Counting Cards Explained
This page describes the math involved in card counting.
The Counting Down From Twenty Song by Have Fun Teaching is a counting song that teaches kids how to count down from 20 to 1 by ones. Free Teaching Resources. Card counting is most commonly used in the game Blackjack, which is also known as 21 in some places. Blackjack is a game played against the dealer. To begin, the dealer deals two cards (face up) to each player and two cards to himself (one face up and one face down). The first step in card counting is to assign values to every card. Cards between 2 and 6 are assigned a value of 1. 7, 8, and 9 are worth 0. 10, jack, queen, king, and ace are valued at -1. A more advanced project would examine different betting and card counting strategies to determine the optimal betting strategy in different circumstances. You can also determine how much 'the house' should pay to a player who guesses correctly, how many decks 'the house' should use to discourage card counting, and how far the dealer should deal. Introduction to the High-Low Card Counting Strategy Introduction. The Hi-Lo Count is the most widely written about, and in my judgment, the most commonly used card counting strategy. The High-Low was first introduced in 1963 by Harvey Dubner 1. It has since been discussed by just about all the major blackjack writers.
In both movies, card counting is the most prominent way that mathematics is used by the main characters. Card counting is most commonly used in the game Blackjack, which is also known as 21 in some places. Blackjack is a game played against the dealer. To begin, the dealer deals two cards (face up) to each player and two cards to himself (one face up and one face down). Each card has a number value attached to it, so 2 is worth 2, 3 is worth 3, 4 is worth 4, etc. Face cards are worth 10, and Aces are worth either 1 or 11. At the beginning of the game, the dealer will announce whether Aces are high (11) or low (1), but they are usually high. The objective of Blackjack is for the sum of your cards to be as close to 21 as possible without going over 21. You lose your money if your cards add up to more than 21, or if the sum of the dealer’s cards is closer to 21 than yours. After the first two cards, each player has the option of asking to be dealt another card (to “hit”) or not. They will decide this based on how likely they think it is that another card would bring them closer to 21 without going over 21.
This is where card counting comes in. Card counting is a strategy using addition and subtraction to determine what kind of card (high or low) is likely to be dealt next. Card counters assign point values to each card that are different from the values I just explained. For card counters, there are point values beyond the obvious ones on the cards themselves. In card counting, cards 2-6 are worth +1, cards 7-9 are worth 0, and 10s, face cards, and Aces are worth -1. Card counters add up all of the cards that have been dealt using this point system, so, for example, if a 4, 8, 10, and queen have been dealt, the point value (or “the count”) would be (+1)+(0)+(-1)+(-1) = -1. Based on the sum of the cards on the table, the card counter will be able to better predict what kinds of cards are left in the deck that have not been dealt yet. If the sum of the cards on the table is very low, then the player knows that there are more low cards left in the deck, so the dealer is more likely to deal a low card. If the sum of cards on the table is very high, then the player knows that the dealer is likely to deal a high card (10, face card, ace) next. With this information, the player will make a more informed and statistically favorable decision about whether or not to ask the dealer for another card. Moreover, the player will bet more money if the count is higher because that means that more high numbered cards are left in the deck. These higher numbered cards are more likely to add up to 21 in the least number of cards. Card counting allows the player to gain an advantage over the dealer/casino over time.
Interestingly, card counting does not require complex math. It involves simple addition and subtraction. However, it does take someone who has a good memory, the ability to maintain concentration, and who is extremely fast at performing addition and subtraction under pressure. Once I learned how card counting worked, I rewatched a scene from “21” and tried to count the cards along with Ben. It was then that I realized just how quickly you must add, subtract, process the result, and make a decision about whether to ask the dealer for another card and how much to bet. Thus, it is not surprising that there are not many successful card counters. However, it is still neat that the math is easily understandable to people who are not mathematicians, and that it does not necessarily take a mathematician to excel in card counting. It involves a lot of practice!
For more information on card counting:
Here is an example of card counting in action in “Rain Man” (start at 1:15):
Here is an example of the math/thought process in card counting in “21”: http://www.imdb.com/video/screenplay/vi3753050393/
Card counting is easily the best known but least understood gambling strategy. You can thank popular films like Rain Man, 21, and The Last Casino for making blackjack card counting a household name. Although it’s fairly easy to learn how to count cards, you’ll quickly discover that this strategy has limitations. While card counting can reduce or eliminate the house edge it isn’t fool proof. Perhaps of greater concern, casinos do their best to deter players from counting cards. Still it’s worth taking the time to understand how card counting works whether you plan on using it or not. Keep reading as we spell out everything you need to know.
The Roots of Card Counting
Card counting first gained international attention in 1962 when a mathematician by the name of Edward O. Thorp released the book Beat the Dealer. Even though this book is beyond out of date, it popularized the whole idea of card counting. As players started putting this primitive system into action, casinos devised methods to curb card counting, including changing the way cards are dealt and shuffled. At the same time, gamblers have devised new card counting strategies. In many ways, the cat and mouse blackjack game continues to this day.
Contrary to popular belief, card counting doesn’t require a photographic memory. Instead, it utilises a simple formula that helps you gauge the ratio of low and high cards remaining in the deck. With this valuable information at your disposal, you can adjust your bets accordingly.
Getting Started with Card Counting
Before you can even begin to think about counting cards, you need to do two things. First, you must fully understand the rules of blackjack. If you haven’t learnt the basics yet, card counting will be beyond your level of comprehension. Second, you’ll want to master blackjack strategy. This is easier than it sounds since all you have to do is refer to a chart that will tell you whether to hit, stand, double down, or split in every situation. When you play according to optimal blackjack strategy, you’ll be able to keep the house edge to a minimum even before you think about counting cards. Fortunately, we’ve created a separate blackjack strategy and game guide that covers both of these topics.
Although there are many different ways to count cards, this guide will teach you how to use the hi-lo card counting system, which is by far the most common. You’ll also see how easy it is to learn.
Assigning Values to the Cards
The first step in card counting is to assign values to every card.
- Cards between 2 and 6 are assigned a value of 1.
- 7, 8, and 9 are worth 0.
- 10, jack, queen, king, and ace are valued at -1.
If you’re wondering why seemingly coveted high cards are assigned a negative value and low cards are given a positive value, the answer is fairly simple. The running count, which we will discuss next, reveals the quality of the unseen cards in the deck. The cards you count are no longer in the deck, which means every time you see an ace or face card the deck becomes less favourable and your advantage as a player is reduced.
What Does Counting Cards Mean
Keeping a Running Count
As the croupier deals cards, you’ll need to start keeping score. You’ll want to keep tabs on not only the cards you and the dealer receive, but also the cards of other players at your table. You might find that it takes you some time to get up to speed, but many of the cards will cancel each other out. For example, if you land a 6 and ace then the value is 0. If the dealer ends up with a king, eight, and 5, the value would be 0. If your tablemate lands a king, 6, 4, the total would be 1. The running count is nothing more than the running count of all the cards you see.
Calculating the True Count
Have you ever wondered why casinos use multiple decks of cards? You can thank card counters for that. Casinos are in the business of making money and the last thing they want is for card counters to eat into their profits. Fortunately, card counters aren’t down for the count. There’s a simple method you can use to overcome the barriers casinos have put up to derail card counting. Just calculate the true count by dividing the running count by the number of decks remaining.
For example, if your running count is -6 and there are 3 decks remaining, the true count would be -2. As the true count rises, your advantage as a player rises as well. Likewise, negative true counts put you at a relative disadvantage.
Placing Your Bets
Once you know the true count, all you have to do is raise your bets as the number rises and reduce your bets as it falls. Think of it this way. The true count reveals the relative house edge. At zero, the house has its standard advantage. When the number is negative, the house has a larger edge. When the house edge is positive, you have the advantage.
Unlike most betting systems that are advertised online, card counting can give you a statistical edge when playing blackjack.
1 Make sure you play blackjack using the optimal strategy.
2 Assign a value to each card you see.
3 Maintain a running count of the totals.
4 Divide the running count by the number of decks remaining to get the true count.
5 Raise your bets as the true count rises and lower your bets as it falls.
- Card counting is perfectly legal but casinos will do their best to stop you from using this strategy.
- Always act natural and try to be as inconspicuous as possible when counting cards.
- It’s important to master the rules of blackjack as well as optimal strategy before attempting to count cards.
- Even though card counting can reduce or eliminate the house edge it isn’t fool proof.
- You will need to place some bets even when the casino has the advantage, otherwise you run the risk of exposing yourself as a card counter.
- It’s impossible to count cards when you play blackjack on the internet.
Frequently Asked Questions About Blackjack Card Counting
How does card counting work?
Card counting is a blackjack strategy used by players to reduce the house edge. As the name suggests, players count or keep a running total of all the high and low cards that have been dealt. Although there a few different card counting systems, players generally assign a positive, negative, or zero value to every card seen and use this running total to gauge the relative house advantage. When armed with this information, you can adjust your bets accordingly.
How is it illegal to count cards?
Despite what you have heard, card counting is not illegal in the United Kingdom, USA, and many other countries. At the same time, casinos don’t appreciate it when players use this game strategy. Casinos may try to ban players who count cards conspicuously.
Counting Cards Explained
How do I count cards?
To count cards, you’ll need to assign a value to each card and maintain a running total as cards are dealt. When you have this information, you’ll be able to calculate the true count by dividing this figure by the number of decks remaining. You’ll want to raise your bet as the true count rises and reduce it as the true count decreases. It’s also a good idea to modify your behavior so the casino doesn’t spot you counting cards.
Basic Card Counting
Can I count cards at an online casino?
While you can try counting cards at an online casino, you probably won’t have much success. Most internet gambling sites shuffle the deck after each hand. When playing live dealer games, you’ll find that the decks are shuffled frequently. When you can’t count deep enough into the shoe, your efforts will be a waste of time.