K-O / Knock Out Card Counting System

The K-O card counting strategy is also known as the Knockout card counting strategy. It’s the easiest card counting system in use for multiple reasons. A full account of how the system works can be found in the blackjack book Knockout Blackjack by Olaf Vancura, PhD, and Ken Fuchs. This page explains how the KO system works and why it’s so much easier to use than most other systems.

No Need to Convert to a True Count

Various card counting strategies exist, but they all try to do the same thing. They measure the advantage that a player has over the house because of the number of high cards compared to low cards in the deck. Since casinos often use multiple decks now, most card counting systems require the conversion of the actual running count to a “true count,” which takes into account the number of decks being used. The K-O Card Counting strategy eliminates the need for a conversion to a true count.

For example, let’s say you’re using a very simple system. You’re going to give a value of -1 to every ace, and a value of +1 to every 5. If you’re playing in a single deck, and you’ve seen four 5’s dealt, but no aces, your count is +4, which means that your chances of doing well are good, and you should increase your bet. But if you’re playing in a game with six decks, you have to divide that +4 by how many decks are still left in the shoe, which is going to reduce that +4 to probably a +1. Addition and subtraction during a card counting session are hard enough, but doing division and estimating how much of the deck is still in the shoe, well—that’s just a lot to ask.

The reason that the K-O system doesn’t require a conversion to a true count is because it’s an “unbalanced” counting system. The simple ace-five count I described in the last paragraph is a balanced system. If you count through the entire deck, the number of 5s and the number of aces will cancel each other out, and at the end, you’ll have a total of 0.

The unbalanced nature of the Knockout system eliminates the need for doing the division, because it compensates for the additional decks.

A Single Level Count

Many card counting systems try to improve the accuracy of their estimate of the player’s advantage by giving different values to different cards. For example, in the Hi-Opt II counting strategy, 2s and 3s count as +1, but 4s and 5s count as +2.  6s and 7s also count as +1, and all tens counts as -2.

In the uber-simple ace –five count I described above, you’re only adding and subtracting a 1 for each important number. That makes it easier to actually accomplish in a casino. Lots of card counting systems have a single level, but many card counting systems try to be more accurate by including the additional levels.

No Side Counts

Another way that some card counting systems try to improve their accuracy is by keeping a side count. For example, you might keep a separate count of the number of aces that have been dealt, in addition to your running total (which you have to convert to a “true count.”) If that sounds like a lot to keep up with, it’s because it IS a lot to keep up with.

How to Count Cards with the Knockout Blackjack System

All card counting systems keep track of the ratio of high cards to low cards by assigning a heuristic value to each card in the deck. In a single-level system, that value will either be +1, 0, or -1. Since the 0s are just ignored, you’re basically just adding or subtracting 1 from the total for each card that you see.

In the KO system, all cards from 2 through 7 are worth +1. All tens and aces are worth -1. The trick with the KO system is that the running count does NOT start at 0. The starting count is based on the number of decks that are being used—this is what eliminates the need to convert to a true count.

The starting number is calculated using the following formula 4 - (4 X the number of decks). So, for example, if you’re playing in a game with 8 decks, you’d start your count at -28. (4 X 8 is 32, and 4 -32 is -28.) You’ll notice that in a game with a single deck, you start your count at 0. The number of decks has a dramatic effect on the count, doesn’t it?

When the count becomes positive, you increase the size of your bet by that many units. So, for example, if the count becomes +4, you’ll bet 5 units. (You’ll be betting 1 unit any time the count is negative or 0.) If the count becomes +1, you’ll bet 2 units. And so on.

This page provides only the most basic of explanations of how the K-O System works, but it’s a very effective and easy card counting system that anyone can learn. If you want to become truly proficient at it, you should read the book Knockout Blackjack.