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What is the Best Card Counting System in Blackjack?

best card counting system for blackjack

There are a few different card counting systems in blackjack, and each one has its own set of unique rules – and its pros and cons. Some are easy to learn and suitable for beginners. Others are more complex but offer greater rewards.

I’ve been counting cards for more than 15 years now, and I have my own favorite (Omega II). But I definitely would not have wanted to learn that system when I was just starting out.

In this article, I’ll describe the most popular systems and discuss the benefits and drawbacks of each one, to help you decide on the best card counting system for you.

Ace 5 System

The Ace 5 card counting method is by far the easiest to learn, and is suitable even for complete beginners to try.

The simple premise behind this system is that you add 1 point to your count for every ace and 5 that you see, and subtract 1 point for every Ace.

You begin to slightly increase your stake when the count is at +2 and increase further as the count gets higher.

The simplicity of this system means that it doesn’t give you as much of an edge as more advanced systems that include more cards. However, some edge is better than none at all, and if used in combination with perfect strategy, the Ace 5 System can still be enough to tip the odds in the player’s favor.

It’s also a good entry-level system to get you used to counting, and once mastered, you can then progress to some of the more advanced methods which can increase your edge.

Hi-Lo System

The Hi-Lo card counting system is probably the most popular system used by blackjack players, and the one I teach in this card counting for dummies guide.

It is a simple system that is easy to learn and use. The goal of the Hi-Lo system is to keep track of the high cards and low cards that have been dealt out of the deck, which in turn indicates the proportion of high and low-value cards that remain.

The Hi-Lo system assigns a point value to each card. The values are as follows:

  • 2-6 = +1
  • 7-9 = 0
  • 10-A = -1

The player will start with a running count of 0. As the cards are dealt, the player will add or subtract the point values of the cards to the running count. A positive running count means that there are more high cards in the deck and is favorable to the player. A negative running count means that there are more low cards in the deck and is unfavorable to the player.

The Hi-Lo system is a very popular system because it is easy to use and it gives the player a good indication of when the deck is favorable. However, there are some drawbacks to using this system.

First, the player needs to be able to keep an accurate running count. This can be difficult to do if the player is not paying close attention to the cards, and once you lose track it’s impossible to accurately get it back until the next shuffle.

Second, the Hi-Lo system becomes less effective at counting multiple decks. That’s why you need to divide by the number of decks remaining to get the true count, which does require some additional mental arithmetic.

KO counting system

The Knock-Out or KO card counting system is a more advanced system that was developed by Ken Fuchs and Olaf Vancura. It is referred to as an “unbalanced” system because, unlike the HiLo, there are more low cards that affect the count than there are high cards.

The cards that affect the KO count are as follows:

  • 2-7 = +1
  • 8-9 = 0
  • 10-A = -1

The advantage of this system is that you do not need to divide the running count by the number of decks remaining to get a true count, instead you can simply use the running count as it is, and begin to increase your stakes when the count reaches +3.

The authors also recommend that you begin to take the insurance side bet when the count is +3 or higher.

The KO system is a more advanced system that can be more accurate than the Hi-Lo system. There are more cards to consider, which makes keeping track of the count more difficult, although this is offset by the fact that a true count division is not required.

Omega II

The Omega II count is a more complex card counting system that was developed by professional blackjack player Bryce Carlson.

Full details are available in his book, Blackjack for Blood: The Card-Counters’ Bible.

It’s used by experienced, professional blackjack players who are proficient at keeping the count and are not put off by Omega II’s additional complexity.

  • 2, 3, 7 = +1
  • 4, 5, 6 = +2
  • 8, A = 0
  • 10 = -2

You can immediately see that the Omega II system is more difficult to use, because it introduces the concept of weighted points depending on the card. To use this system you will need to remember which cards are worth +1 and which are worth +2, and be able to update your total accordingly.

As with other card counting systems, you restart from 0 after the decks are reshuffled, and increase your stake the higher the count. When the count is zero or negative, you play minimum stake or even skip a turn if you can get away without making it too obvious.

The Omega II system is a more advanced system that can be more accurate than the Hi-Lo or KO systems. However, it can be more difficult to use because the player needs to keep track of the cards in multiple categories.

Red Seven

The Red Seven count is the brainchild of Arnold Snyder. It is another unbalanced system and is unique in the fact that it scores 7s differently depending on whether they are black or red.

Full details are available in his book, Blackbelt in Blackjack.

The point values in the Red Seven system are as follows:

  • 2-6 = +1
  • Red 7 = +1
  • Black 7 = 0
  • 8, 9 = 0
  • 10-A = -1

Another unique aspect of Red Seven is that it requires changes to standard basic strategy rules, depending on the count.

For example, with a running count of +2 or more, the following changes apply:

  • Stand on 12 against dealer 2
  • Stand on 15 against dealer 10
  • Double down on 10 against dealer A

These plays may sound counterintuitive to those who are well-versed in basic strategy, but the logic is explained in Snyder’s book.

The strategy changes, combined with the unusual counting method, make Red Seven a more difficult system to learn than the HiLo or KO. Its nuances make it difficult to learn alongside another system. Therefore I would recommend that if you want to learn Red Seven, you focus only on this system and do not learn another as an alternative.

That said, it is powerful and effective once you have mastered it, and does give the player an advantage over the house.


The KISS count is a system that was developed by professional blackjack player Fred Renzey. It is another unbalanced system (dealing the whole deck will not result in an end count of zero) and, like Red Seven, it treats colored cards differently – in this case 2s rather than 7s.

Full details are available in Renzey’s book, Blackjack Bluebook II.

The point values for KISS II are as follows:

  • Red 2 = 0
  • Black 2 = +1
  • 3-6 = +1
  • 7-9 = 0
  • 10 = -1
  • A = 0

Some players prefer to start out with a negative count after the shuffle, to ensure that the deck is strongly in their favor before they begin to increase stakes. Alternatively, you could just adjust the point at which you begin to increase.

The obvious difficulty with KISS II is that you need to remember to give different scores to any 2s that are dealt, according to their color. However, I feel this is compensated by the fact that four different cards return a zero value, so they can be ignored. This makes the system much easier to use because there are fewer cards that you need to keep track of.

I feel that KISS II is a good all-round intermediate system, offering a balance between effectiveness and ease of use. If you feel that Ace-5 and HiLo are a little basic for your abilities, then I would recommend KISS II as the next step in your card-counting journey.

Zen Count

Arnold Snyder (author or Red Seven) is back again with another card counting system, this time known as the Zen Count. This is another weighted system which has more similarities to Omega II than to Red Seven.

Full details of Zen Count are available in Snyder’s book, Blackbelt in Blackjack. That’s the same book that contains Red Seven, so it gives you two systems for the price of one.

Zen Count has a more complex scoring system than any I have described so far:

  • 2-3 = +1
  • 4 – 6 = +2
  • 7 = +1
  • 8-9 = 0
  • 10 = -2
  • A = -1

As you can see, this is not for beginners and not for the faint-hearted! It takes some time to learn the point values, and yet more time to become proficient at applying them to your running count during a fast-moving blackjack game.

To ramp up the mental arithmetic, Zen Count also requires you to keep a true count (by dividing the running count by the number of decks remaining).

But when you do manage it, the rewards are worth the effort – if you play regularly of course.

Zen Count is a highly effective system that will give you a strong edge over the house. If you’re a casual player who only spends a few hours a month at a blackjack table, then I would say that Zen Count is not worth the effort and you should learn a simpler system instead.

However, if you are a regular or professional blackjack player then this is one of the best card counting systems out there, and the time and effort spent learning Zen Count will be well rewarded in the long term.


There are plenty of Card Counting Systems that work – but there is no single “best” system to use because each one has its own pros and cons. By now, you should have some idea of which system you feel will be most suitable for your individual needs.

  • Ace-5 is a very simple system that is easy to learn and use, but it is less effective.
  • Red Seven is a more advanced system that is more difficult to use, but it is much more effective than Ace-5.
  • KISS II lies somewhere in the middle, offering a balance between effectiveness and ease of use.
  • Zen Count is an extremely effective system, but it is very difficult to learn and use.

The best card counting system for YOU depends on your own preferences and needs. If you are a casual player who just wants to have some fun at the blackjack table, then Ace-5 or HiLo would be a good choice. If you are a more serious player who wants to have the best chance of winning, then Red Seven or Zen Count would be better choices.

Whichever system you choose, make sure you practice it thoroughly before using it for real money. There is no point in learning a card counting system if you are not going to use it correctly!

Last Updated on October 6, 2022

David Graham
Posted in Strategy

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