Blackjack card counting

In the hushed halls of casinos, where the subdued lighting contrasts with the intensity of the stakes, there is one intriguing practice: card counting. A formidable mathematical technique, it transforms some players into veritable strategists capable of defying the casino’s advantage. But can you really beat the bank by playing fair?

Card counting in blackjack is no urban legend. It’s a decades-old statistical strategy based on a simple truth: in blackjack, the cards already played influence the chances of the next ones. Keeping an eye on the cards can therefore help you adjust your bets and even anticipate moves.

Blackjack

Blackjack is a popular card game played in casinos, pitting each player individually against the dealer. The aim is to obtain a hand as close as possible to 21 without ever going over. It is possible to increase your chances of winning at blackjack by following a table of optimal decisions, considered to be the basic strategy, but card counting allows you to go even further and even gain an advantage over the casino in the long term.

A mathematical technique, not cheating

Contrary to popular belief, card counting is not illegal. In fact, it does not require any electronic device or outside intervention. It is a mental method, based on memory and calculation. By following the cards played, the player can determine whether the remaining pack is favourable to the players (with more 10s and aces), or to the croupier (with lower cards).

The best-known system, Hi-Lo, assigns a value of +1 to low cards (2 to 6), 0 to neutral cards (7 to 9) and -1 to high cards (10, tricks, aces). The player adds up these values over the course of the game to obtain a running count, then divides it by the number of packs of cards remaining to obtain the true count: the higher the true count, the more advantage the player has.

There are other, more complex counting systems with values other than -1, 0 or +1. They are more difficult to learn and use, but more accurate than the Hi-Lo system.

It is also advisable to count the number of remaining aces separately. Since these cards can be worth 1 or 11 points, they are very advantageous.

Geniuses against the casino

The history of card counting is littered with mythical figures. The book Beat the Dealer by American mathematician Edward O. Thorpe first popularised the method in the 1960s.

Later, the MIT Blackjack Team, a group of university students, used mathematics to win millions of dollars at tables in Las Vegas and Atlantic City in the 1980s and 1990s.

These students did not play alone. They formed a real organisation, with spotters, big players and a system of discrete signals. Each player trained for several months before playing in a real casino. Their method was not illegal, but it was frighteningly effective, so much so that several members were banned for life from numerous casinos.

Legitimate but frowned upon: the reaction of the casinos

Faced with these ‘intelligent gamblers’, the casinos did not stand idly by. Even though card counting is legal in most jurisdictions, gaming establishments retain the right to exclude any player for any reason. And they use it.

Today, casinos use a panoply of sophisticated countermeasures: automatic card shuffling, continuous clogging, advanced video surveillance, staff rotation, betting limits, etc. The aim is to make counting ineffective or difficult to implement. Some even employ teams of behavioural recognition experts to identify potential counters.

A difficult strategy to master

Card counting is not for everyone. It requires a great deal of concentration, an excellent memory and, above all, unfailing discipline. You need to keep your cool, even in the event of a prolonged loss, because the strategy does not guarantee an immediate victory, but a long-term statistical advantage.

Moreover, counting cards without being spotted requires a mastery of behaviour: remaining natural, not suddenly changing your bets, avoiding suspicious glances. Many players fail not because they miscalculate, but because they are over-zealous.

A double-edged sword

Counting cards in blackjack is not a magic formula for getting rich. It is a demanding mathematical strategy that is supervised, monitored and often fought against. It requires work, rigour and a certain discretion. But it does prove one thing: in the realm of chance, reason can sometimes have the last word.

If you feel like it, practice and test yourself, but be aware that casinos are no fools. And in this silent battle between human brains and profit machines, every victory is dearly won.