An Introduction to Card Counting in Blackjack

Blackjack, like every other casino title, is designed to give the house a slight edge. This advantage varies from game to game. In blackjack the house edge is around 0.6%. This means, statistically, if you play long enough, you will eventually lose. The house always wins.

However, a mathematical technique known as card counting can be used to tip the odds in your favour. Learn how to count cards, and it won’t be the house with the statistical advantage, it will be you. But is counting cards illegal? Strictly no. It is frowned upon and casino companies try to prevent it being used by implementing an array of countermeasures. There are several methods, but all are based on the principle of keeping a running tally of previously dealt cards in order to predict more accurately if a high or low card is likely to be dealt.

How to Count Cards in Blackjack?

In its most basic form, card counting in blackjack involves applying a positive, negative or neutral value to each card dealt, allowing players to calculate an overall value of the deck or decks in play. Armed with an accurate value, players can bet accordingly to minimize risk or maximize profit. The higher the count the more advantage the player has, and therefore the bigger the bet should be. The lower the count, the less likely the player to be dealt a favorable card and therefore lower bets will reduce losses. Card counting can either be done in-play, or by overlooking a game table and entering when the count is high. This technique of striking while the table is hot is known as back-counting.

image of the true count formula

To count cards in blackjack you must add, subtract or assign a value of zero to each card dealt. Card counting is not complex mathematics – some systems, like the Hi-Lo for example, require only basic arithmetic – but keeping up with the speed of play requires concentration. You may have seen card counting depicted in movies such as Rain Man or The Hangover as a super-human skill, but the reality is that counting cards can be done by anybody. During the game, the count is altered with every card dealt to either player or dealer. By logging a card that has been dealt, and is therefore ‘dead’, players can calculate its “effect of removal” or EOR. More complex systems of can provide a more accurate EOR value, but are more difficult to count. Let’s start with the easiest, and most widely attempted.

image depicting how card values are calculated for card counting

This simple but effective method of card counting is the known as the Hi-Lo system. To count cards using the Hi-Lo System Each 10, Jack, Queen, King or Ace dealt decreases the count by one. Cards valued 2-6 increase the count by one. Cards valued 7 to 9 are valued at zero and therefore do not affect the count. The system is known as a ‘level one count’, as the running value never changes by more than one with each new card. Multi-level counts, such as the Zen Count or Halves, can increase overall accuracy but involve adding or subtracting one, two or half a point to the value of the deck. Some multi-level methods also require the card counter to keep a side count alongside the main count, like also keeping track of the number of aces dealt.

Use the Hi-Lo System of card-counting at the best online casino of the year!

Aside from the added difficulty of keeping a multi-level count, there’s also the added exposure to consider. Players keeping complex counts are less likely to be able to play quickly and accurately, thus raising suspicion from dealers and casino security. Assuming you have calculated an accurate value, what’s next? Ranging your bet sizes relies on a mathematical principle called the Kelly Criterion, a probability theory that has become part of mainstream investment theory. The idea can be simplified for card counting in blackjack, and results in players scaling the size of their bets per the running count.

Known Instances of Successful Card Counting

Card counting has been used successfully for decades. Dr. Edward O. Thorp, and American Mathematician, is considered the father of the method after he outlined optimal blackjack play in his 1962 book, Beat the Dealer. More recently, teams of card counters have been deployed to further minimize risk. A team requires several back-counters, called ‘spotters’, to value multiple tables in a card room. A ‘big player’, often assuming the role of an eccentric high-roller, moves from table to table placing large bets depending on the count. This practice can be extremely profitable, as the player only gambles at tables where there is an advantage.

The MIT Blackjack Team

The Logo of Massachusetts Institute of TechnologyOne of the most famous card counting teams was put together at the Massachusetts Institute of Technology (MIT). The team operated from 1979 until around the turn of the century and ran successful card counting operations at casinos in Atlantic City and later worldwide.

The film “21” is based on the book “Bringing Down the House” by Ben Mezrich, about the 90s MIT blackjack team.

At one stage in the 1980s the team is thought to have grown to as many as 35 players making as much as $350,000. Mezrich’s book became a best-seller, eventually motivating the author to write a sequel on the same subject titled Busting Vegas. The book also attracted a lot of negative attention due to several historical inaccuracies throughout the story that Mezrich has since admitted to have taken leeway on.

The Tommy Hyland Story

Thomas (Thommy) Hyland also began his card counting operation in the 1970s. Inspired by Lawrence Revere’s book, Playing Blackjack As a Business, Hyland hit Atlantic City with his team in 1979. The four members had originally contributed $4,000 each to bankroll the operation, and within a few months had built their pot to $60,000. The founding members fled to Asia when conditions in Atlantic City worsened but Hyland remained, forming new teams. In 1994, members of Hyland’s blackjack team were arrested in Windsor, Canada, for cheating. It is believed that major Las Vegas casinos influenced authorities in Winsor to prosecute, but a judge ruled that Hyland’s crew were merely using intelligent strategy and thus were not guilty of cheating. Hyland is on record as counting cards in blackjack as recent as 2003. Since the beginning he has used the Hi-Lo method exclusively.

How do Casinos Prevent Players Counting Cards?

Whilst card counting is not illegal, Caisnos have introduced several countermeasures over the years in an attempt to wrestle back the advantage from players. These measures range from changing betting limits on the tables, to blacklisting known card counters. Does counting cards work online? That depends. The effect of this strategy is reduced in online blackjack as the single 52-card deck is shuffled after every hand. Players get what is known as ‘true odds’ on every hand. However, with the addition of video blackjack and live casinos, online blackjack can be played under the same conditions as in a land-based casino. This means that card counting once again becomes a profitable strategy. Many professional card counters also use online blackjack as a training ground. With low minimum bets, online blackjack is the perfect place to sharpen your skills without risking a lot of cash. Have a look at the wide variety of blackjack games on offer, and test your card counting clout.