Blackjack – Count cards like a pro

Blackjack, also called “21”, is next to Roulette certainly the most popular game in the casino. Blackjack has always fascinated gamblers and mathematicians, because it was or is actually possible to beat the casino.

In the 1960s, Edward O. Thorp published a groundbreaking book entitled “Beat the Dealer”, which ultimately earned him the nickname “Father of Card Counting”.

In his book, he introduced a revolutionary scoring system that has since been used successfully by amateurs and professional card players across two generations.

Counting systems have evolved since then and there are now a plethora of techniques that are more or less similar. Some are more complex than others, but in the end they all give the player an advantage over the casino.

Card counting is actually pretty simple mathematics.

The only skill you need is good addition and subtraction and you have to be able to do mental arithmetic like a machine gun. Not everyone has this ability, but one thing should be clear: The less effort you have to put into mental arithmetic, the better you can concentrate on looking like a normal player at the table.

The High-Low System (also known as Hi-Lo)

One of the most profitable and perhaps easiest ways to count cards is known as the Hi-Lo strategy (high and low cards are each assigned a value). This system is essentially a continuous counting technique where each card has a specific value.

The system is used to find out when the ratio of high cards already played to low value cards is no longer in balance. Cards such as the 10, face cards and aces, not only increase the likelihood that a blackjack is imminent, they also increase the likelihood of future hands that are worth at least 20. A deck with a lot of high cards puts the player in a winning situation because it increases the chance that the dealer will lose. If the majority of all cards in the deck have a value between 2 and 6, the dealer has a significant advantage over the player. The more high cards left in the deck, the higher the probability that the dealer will lose.

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1. How Hi-Lo works

From the first card dealt by a dealer from a shuffled deck, the player starts counting card values (+1, 0, -1).

A low card (2,3,4,5,6) increases the count by one point, a high card (10, Jack, Queen, King, Ace) decreases the count by one point.

This is called “consecutive counting”. Cards 7-9 are neutral and are not counted in the Hi-Lo system.

For example, the count for any round might look like this.

Now calculate the final number for that round and it should result in a value of +1.

This means that more cards of lower value have already been played and consequently there must be more high cards in the remaining deck (10, B, D, K, A).

However, it should be remembered that after only a few hands have been played, the count may not be very accurate. It is therefore very important for accuracy and for the advantage over the casino to gather more information.

If you are playing blackjack for the first time and have never counted cards before, you can count through an entire pack of cards once for practice. If you have counted accurately, you will end up with a “0”.

In the beginning there will probably be many mistakes in counting, but the more often you practise, the faster and more precise you will become at counting. After a while, you can try counting two cards at the same time by simply looking at your hands. After some practice, you will even be able to recognise different card combinations and their value. And this is what makes the relatively simple Hi-Lo strategy so special: as a technique it is quite uncomplicated and simple.

It will not take long before this simple technique can be used in a normal game at normal speed. To do this, you have to think about the current value of the cards and at the same time pay attention to the game without attracting other people’s attention.

If the counting system is not yet mastered by heart and one thinks for a long time before the current value can be deduced by counting, one will quickly find oneself confronted with security guards and the dealer, because they are trained to recognise card counters.

2. The true card counting

Once card counting has been mastered, the next step is to acquire the knowledge of what bets should be played and when. As mentioned earlier, a rule of thumb is that the more advanced the deck, the more predictable the outcome.

This is where a new factor comes into play, known as the True Count. Here, the running count is divided by the estimated number of decks remaining on the table. Here at the latest, beginners will usually be confused.

Let us look at an example.

The running count is +7 and there are c.a. 4 decks left on the table. The true count would therefore be 7/4 = 1.75. Round the value to 2.

By making the running count the true count, you get a more accurate estimate of whether or not you have an advantage over the casino.

Nowadays, you will not find many tables with only one deck, so it is likely that a table will be played with multiple decks. There may be between two and eight decks in play, so the number of decks remaining must be estimated.

One way to determine how many cards have already been dealt is to look at the discard pile on the table (if there is one). This can be practised at home by stacking packs of cards on top of each other.

After estimating how many decks have been played, this number must be subtracted from the decks that started the game. This is the number of decks remaining.

An example of a game with six decks:

The running count is 12. Looking at the discard pile, it is estimated that approximately three decks have been played, leaving three decks. The running count of 12 is thus divided by 3, so that the true count is 4.

3. What bet is placed at what time.

Now it gets interesting. The basic rule is: the higher the true count, the higher the bet.

This is where card counting becomes more of an art than a science. Some books on blackjack give strict rules on how to proceed. However, casino employees know the published techniques and some recurring patterns can give the card counter away very easily.

As a card counter, the key to making money is to increase the bets when the deck is “hot” and decrease the bets when the deck is “cold”. The difference in bet size is known as the “Betting Spread”. The size of an individual “betting spread” depends on a variety of personal factors, such as the size of one’s bank, one’s personal condition, knowledge of card counting, knowledge of the rules, etc. The size of the betting spread depends on the size of one’s bank.

In order not to attract the attention of casino staff unnecessarily, a “Betting Spread” of between 1 and 5 units is recommended. This means that 1 unit should be bet on a +1 count, on all neutral counts and on all negative counts. A +2 count means 2 units are bet, a +3 count means 3 units are bet and a +4 count means 4 units. Anything over +4 means a bet of 5 units.

Any bets over 5 units are very likely to bring up the casino. The amount of individual bets depends on personal preference. To stay under the radar, find a value between the table minimum and the maximum for that table.

The player must estimate the maximum of the count. In other words: How high can the current round’s count get? For simplicity, we estimate that the maximum count is 10. This means that the player’s maximum personal bet is €100, a multiple of €10.

Of course, you could consider playing only at “interesting” tables, i.e. when the deck is “hot”. However, this requires a team of card counters.

In fact, anyone who has seen the film “21” (2008) has not only experienced an entertaining film, but has also been able to observe well how successful a good team strategy can be.

By means of card counting, it is indeed possible to gain a decided advantage over the casino.


Casinos are not stupid! Although card counting is neither legally prohibited nor punishable in Germany, nor in the USA, casinos will not (and cannot) ignore card counters.

Some of the most common countermeasures:

  • Increasing the number of decks in a deck. Blackjack used to be played with only one deck. Later with 4 decks and now it is usually already six.
  • The deck is never played to the end. After a third or quarter of the deck has been played, the deck is reshuffled.
  • The player’s bets are limited, for example:

(a) Double down is only allowed on “hard totals” of 9, 10 or 11.

(b) No doubling down is allowed after two cards of the same group have been split.

These countermeasures help the casino, of course. However, card counters are still able to play profitable systems anyway.

That is why many European casinos now use “shuffle stars”, special decks of cards. Cards played are immediately shuffled back into the remaining cards. This makes each round independent of the next, like in roulette. Thus, card counting in most casinos today has not only become difficult, but also a part of the past.

We hope that this article has been able to enlighten you about blackjack and card counting. Once you think you are already up for card counting, you might as well give it a try yourself.

However, serious gambling does not mean going to the next best online casino, but finding the best casino. But which casino is the best? How can you recognise good online casinos and which ones are particularly suitable for German players? This question is not so easy to answer, as there are a few factors that should be taken into account.

John Shallo
John Shallo
John Shallo is the founder and editor of Cruise Addicts. Since 1999 it has been a leading destination for cruise travelers and self professed Cruise Addicts looking for the latest news, ship reviews and travel tips.

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