K-O System

Written by Dean McHugh
Dean McHugh
Dean McHugh is a full-time writer with more than 20 years of experience in the iGaming industry. Specialising in casino reviews, slot analyses, and sportsbook evaluations, he delivers clear, engaging, and insightful content for both industry professionals and casual players. Over the past four years, he has contributed extensively to leading iGaming comparison websites.
, | Updated: Fri 29 August 2025

Blackjack is one of the most challenging casino games, as it requires skill and knowledge. This is why a number of strategies have been developed over the years to help players increase their chances of winning. One very popular method is card counting, which has many variations and systems.

They vary in terms of effectiveness and level of difficulty, which helps players decide which is the most suitable for them. In general, card counting is practised by advanced gamblers, as it requires experience and a solid knowledge of the basic strategy. However, nowadays, due to the huge interest in Blackjack worldwide, there are many card-counting systems available, which differ mainly in the way the count is conducted and in their assigned values.

One such method is the K-O system (Knockout Count), as it gives players the opportunity to make wiser decisions for their moves and bets. It is both simple and effective, which makes it the perfect strategy for beginners. Although it is relatively easy to learn, it still requires a great deal of practice and concentration, as, after all, it uses the main card-counting principle of assigning new point values to the cards.

Brief History

The K-O system grew in popularity incredibly quickly in 1998, when Ken Fuchs and Olaf Vancura published one of the most famous books about Blackjack – “Knock-Out Blackjack – The Easiest Card Counting System Ever Devised”. This card-counting system encouraged many players to invest time and effort in learning, as it proved that even beginners could gain an advantage over the casino by using such systems.

Assigned Card Values of the Cards in the K-O System

As already mentioned, the K-O system is not only simplified but also accurate and effective. Just like the rest of the card-counting systems, it uses the main principle of assigning particular point values to the ranks of the cards. This strategy is very similar to the popular Hi-Lo system, which is very convenient for players who are already familiar with this basic card-counting method. The only card rank that has a different assigned value compared with the Hi-Lo system is seven, and players should pay special attention to this detail.

The K-O system offers the following plan: the numbers from two through seven receive a plus-one value, eight and nine get zero, and for the rest of the cards the count is minus one. In order to make it work and keep track of the cards successfully, players need to count them with their assigned value instead of their real one. This way they will be able to determine whether or not they are in a favourable position and thus choose the best possible move for their hand.

K-O Card Counting System
Card ValueCount
2, 3, 4, 5, 6, 7count +1
8, 9count 0
10, J, Q, K, Acount -1

Classification of the K-O System

For players’ convenience, each card-counting system has a level of count that indicates how difficult it is to learn and apply. This information can be extremely useful when deciding whether a particular strategy is suitable or not. The K-O system is a level-one count, which means that it is specifically designed to be appropriate for all players, regardless of their knowledge of card-counting systems.

Another important classification of card-counting systems is whether they are balanced or unbalanced. In contrast to the Hi-Lo system, which is balanced, the K-O system falls into the category of unbalanced systems. This means that if players count through the whole deck, the final number will not be zero.

Important Considerations

There are a few important factors that should be taken into account if players decide to use the K-O card-counting system. Prior to playing, it is crucial to pay attention to the number of decks involved in the game, as this will determine the count with which players should begin. The principle that a positive count gives players an advantage over the casino applies to this strategy as well, and they should be familiar with it in order to make the best possible betting decisions.

Benefits of the K-O System

Probably the biggest benefit of this system is that it is very straightforward and easy to learn. Even inexperienced players will be able to take advantage of it and apply it in the casino. It is also very effective and accurate, allowing them to adjust their bets accordingly and, in turn, win more money. It is a great card-counting system, as it provides everything they need to increase their winning hands.

When it comes to card-counting systems, the phrase betting correlation is often used; it indicates how well a particular system forecasts how advantageous the upcoming cards will be for the players’ bets. It is measured in points, and the higher a system is rated, the greater the accuracy it provides. In this sense, the betting correlation of the K-O system is 0.98, which in itself indicates that it is worthwhile.

Conclusion

The K-O system is a great card-counting strategy for all kinds of players, regardless of their experience and mathematical skills. To succeed, it is necessary to be extremely disciplined and organised. Even though many card-counting strategies are simplified and easy to learn, players need to bear in mind that a great deal of effort and dedication are still required. In order to achieve the desired result, they should be extremely focused and know the chosen system backwards and forwards.

This system is perfect for players who have just discovered their interest in card counting strategies, as it is very easy to understand and does not require complicated mathematical equations. It is very similar to the famous Hi-Lo system and is therefore reliable and accurate. It gives players the unique opportunity to predict, to some extent, the upcoming cards and use this valuable information to adjust their basic strategy and place suitably sized bets.