Card counting isn't just something that savvy mathematicians do in the movies. It's in fact very real and potentially very profitable. Some card counters are so talented at the practice that they can earn millions of dollars in a single night. 

But what exactly is blackjack card counting? And how does it work? Continue reading and we'll walk you through everything you need to know about card counting and how you can use it the next time you go to the casino.

The Origins of Card Counting

Blackjack wasn't legally played in casinos in America until the 1930s. But it wasn't until the 1960s that blackjack card counting would become a real thing. It all started with a mathematician by the name of Edward O. Thorp. 

Thorp received his Ph.D. in mathematics at UCLA in the late 1950s. He then went on to teach math at MIT, New Mexico State University, and UC Irvine over the next several years. 

After earning his degree, he became very interested in the game of blackjack. Using an IBM 704 computer, he researched the probability of winning blackjack with different hands. 

After much research, he came up with what he called a "ten-count system." With this system, he would start with two numbers in your head - 36 and 16. The 16 represents the 16 cards with a value of ten and the 36 represents the other cards. 

As cards were dealt out during the game, he would count backward and divide that count with the number of remaining "other" cards. This was back in the day when there were single-deck games. Using Thorp's method on today's eight-card decks would mean that you would have to start with the numbers 288 and 128 and then count backward while also doing division.

Thorp took his system to the casino one weekend with $10,000 in hand. He left the casino a few days later with $21,000 in his pockets. News spread quickly of Thorp's method and he became a celebrity among the gambling community.

Then, in 1966, Thorp wrote his seminal book Beat the Dealer. It was an instant success and even became a New York Times bestseller. 

The Casinos React

As we can imagine, the casinos weren't too pleased that Thorp had figured out a way to beat the game. They started to implement changes.

For example, they went from single-deck games to four-deck games. Blackjack dealers were also required to reshuffle more often. However, the casinos soon realized that Thorp's book was actually good for them.

Suddenly, floods of wannabe high rollers started coming in and playing blackjack. But these new players didn't have the patience or the skills needed to apply Thorp's system. Despite Thorp's book, the casinos were doing better than ever. 

Hi-Lo Count

Going off of Thorp's work, a computer programmer by the name of Harvey Dubner invented a counting system known as the Hi-Lo Count. As computer systems became more popular, programmers were able to take the variables that casinos kept adding and determine what their advantages would be. 

The Griffin Agency

The reason why casinos don't make blackjack a lot harder is that they want the game to still be attractive to players. Even if you play perfect basic strategy, the house still has an edge and is thus likely to win your money. Because of this, they even encourage players to try and beat the game. 

Dealers know exactly what basic strategy suggests and they're more than happy to offer the system's advice whenever a player is deciding what to do. But what were casinos to do about players who actually figured out how to beat the house?

Robert Griffin, a private detective from Las Vegas, came up with a solution to this problem. He made a book that contained information and pictures of suspected and known card counters and sold it to the casinos. He would constantly update the book and sell them newer versions too. 

Team Play

A card counter by the name of Al Francesco devised the team play system in 1971 as a way to avoid being caught by pit bosses. He would go to the casino with his brother who was also a counter. While his brother sat, Al would sit next to him and pretend to have a conversation. 

Whenever his brother placed a large bet, Al would casually throw down $100. The scheme was so successful that he became the first Big Player in blackjack history. Al would go onto train other players including Ken Uston.

Uston went on to write a book about the strategy. This book led to a major increase in people engaging in team play, including the MIT team which the movie 21 is based on.  

Stanford Wong

Stanford Wong took card counting to another level. After earning a Ph.D. in economics, he wrote a book called Professional Blackjack and wrote about his own strategy. He suggested back-counting and hopping around different tables to find the best shoes.

By counting cards but only betting when the count was in his favor, he could avoid losing money and he could also avoid attention by not making constantly shifting bets. 

Also, during this time, casinos weren't as worried about using computers. Players would design complex machines that they could hide inside of their clothes. They would input information by tapping their feet and then the computer would output information through vibrations.  

What Is Card Counting?

Essentially, to count cards means that you are keeping a general mental record of the cards being dealt. Because you know how many cards are in the shoe, and which type of cards are still left, you can more or less determine if you have good or bad chances of winning upcoming hands. The most popular method for counting cards is Harvey Dubner's Hi-Lo count. 

How the Hi-Lo Count Works

First off, it's worth pointing out that you don't need a Ph.D. in mathematics to count cards. You just need to be someone who is patient, level-headed, and disciplined. 

The very first step to being a successful card counter is learning basic strategy. Card counting is useless unless you can master and memorize basic strategy. This system is a strategy that tells you the mathematically optimal move for every possible hand in the game. 

Once you have basic strategy down, it's time to learn the running count. To do this, we're going to have to give a value to every card. Imagine separating a deck into three chunks.

The cards numbered 2-6 will be our low cards. They will have a value of +1. So every time you see a 2, 3, 4, 5, or 6, you're going to add 1 to your running count. 

The 10 through Ace cards are your high cards. They have a value of -1. Cards numbered 7-9 are neutral and have a value of zero. 

Keeping a Running Count

To practice keeping a running count, you should flip over cards in a deck one at a time. As each card comes out, attempt to keep the count going at a steady pace. By the time you reach the end of the deck, your running count should equal zero if you were doing it correctly.

When at a table, you can use the hi-lo system no matter how many decks are in the shoe and no matter what the specific rules of the game are. When keeping the count, you need to make sure that you are counting every single card that comes out. Not just your card but the cards of the other players and the dealer too. 

You want to continue counting until the cut card comes out and the dealer reshuffles. When this happens, the count resets. 

As more low cards continue to come out, that means that there are more high cards on the verge of being dealt out. This is how blackjack is different than any other game in the casino. 

Other games are based on the spin of a wheel or throw of the dice. But with blackjack, all of the hands are cumulative. Cards that come out of the shoe aren't going to be in play again until the shoe is reset. 

Calculating the True Count

Unfortunately, keeping a running count isn't enough to give you a good advantage. Having a running count of +10 but with five decks still left in the shoe will be different than that count with only one deck left. Because of this, we also need to calculate the true count. 

Figuring out the true count requires only some basic division. To calculate it, you divide the running count by how many decks remain in the shoe. Let's go over an example.

Imagine that you have a running count of +15. If you have five decks left then you calculate 15/5. This would mean that your true count is 3.

This information will determine how you bet as well as which playing decisions to make. 

Using the True Count 

When counting cards, there are times when you don't want to follow basic strategy. Only when you know how to use basic strategy as well as calculate the running and true count can you gain an edge over the casino. 

The higher the true count gets, the more you should increase your bet. Also, as the true count gets higher, you'll spend more hands standing, doubling, splitting, and surrendering. If your True Count is +4 or greater, you will always want to stand.

This is because a high count means there are more high cards in the shoe. And if you hit, you increase your chances of busting. But you also have better odds of being dealt out a winning hand. 

Is Counting Cards Allowed?

Contrary to popular belief, counting cards is not illegal. You're not cheating when you're counting cards and you're not committing fraud or tampering with any equipment. 

All you're really doing is doing mental math. And there's nothing against the rules about doing mental math. With that said, casinos can ask you to stop playing. 

Casinos are private institutions and they have the ability to tell you to stop. Yet, they can't always do that. For example, the New Jersey Supreme Court ruled that casinos can't discriminate against card counters, even if they know they're counting.

So instead, if you go to Atlantic City, you'll see that they use eight-card decks and that dealers are shuffling a lot more often. This is to inhibit card counters from playing. 

This is much different than in the Las Vegas casinos. If you get caught card counting in a Nevada establishment, the pit boss will come up to you and tell you that it's time to play a different game. 

How to Avoid Being Caught

Perhaps the most important thing to remember is to play it cool. Don't count out loud or move your lips. Try to keep all of the math in your head.

Also, don't drink alcohol. Non-alcoholic drinks are fine but drinking alcohol can quickly lead to major slip-ups. And if you start winning a lot, don't be afraid to throw in some misdirection.

Purposefully making bad bets or bad decisions can throw the pit bosses off your trail. And also remember to tip your dealer. Tipping helps to get the dealer on your side and it also distracts them. 

The Importance of Knowing About Blackjack Card Counting

As we can see, blackjack card counting is something that most people can do. However, it's something that most people aren't willing to put the time and energy into. But if you commit the effort, you can be counting cards as well as your winnings in no time.

Looking to play some blackjack right now? Be sure to check out our many blackjack games and start playing!