# Blackjack Card Counting Strategies

Blackjack is a casino game based on conditional probability which is precisely what makes it beatable. This means what happened in the past affects the probability of what is going to happen in the future. Once a given card is dealt on the blackjack table, it cannot appear again until the dealer finishes the deck or shoe and reshuffles.

If you take a single deck of cards and pull out the Ace of hearts, for example, you cannot draw it again until you reintroduce it into the pack. This peculiarity of blackjack renders it susceptible to advantage play techniques such as card counting.

Card counters use systems which allow them to keep track of the cards that have already been removed from the deck or shoe. This gives them an accurate idea of which cards remain to be played before the reshuffle. Card counters capitalize on shoes that are rich in favorable cards by placing larger bets. Conversely, when the remaining cards favor the house, smart players reduce the amounts they bet because they are at a disadvantage.

Card counting is not as complex as it appears. There is no need to memorize the exact order in which the cards are dealt like many people seem to think. You simply keep track of the ratio of high to low cards. And to achieve this, you need to use a card counting system. There are many card counting systems out there but what are the differences between them and which one should you choose?

## Classification of Card Counting Systems in Blackjack

Before we proceed to discuss classification, we should provide an answer to the question “Why are there different card counting systems to begin with?”. The main reason is different systems attempt to solve different problems.

Some systems are quite easy to learn and use but they are not as effective in pitch games. Others yield higher efficiency at the single-deck and double-deck tables but are not as effective or simple to use in shoe games with multiple decks. Card counting systems can be classified on the basis of three main criteria – balance, level, and side counts. Let’s take a look at balanced and unbalanced systems first.

### Balanced vs. Unbalanced Card Counting Systems

Card counting systems are either balanced or unbalanced. The most popular example of a balanced system is the Hi-Lo which is the system of choice of many professional blackjack players. Balanced systems like the Hi-Lo always start and end at zero.

If you take a standard deck and go through every single card in it, you will inevitably arrive at a running count of zero after you pull out the last card. If you arrive at any other number in the end, you most certainly have made a mistake in the running count.

This is not the case when one uses an unbalanced counting system. Unbalanced systems like Red Seven and KISS, for example, can start with a value other than 0 and have pivot points that indicate when the card counter must adjust the size of their bets.

### Single-Level vs. Multi-Level Card Counting Systems

Card counting systems can also be classified on the basis of their level. Players who use single-level systems assign values of +1, -1, or 0 to the cards as they keep a running count. The Hi-Lo is a single-level counting system where the high cards like Ace, 10, King, Queen, and Jack are assigned a value of -1 because they favor the player and the low cards deuce through 6 are counted as +1 because they favor the house. The cards with denominations of 7, 8, and 9 are considered neutral and as such have no value, i.e. they are counted as 0.

Another popular example of a single-level system is Hi-Opt I where cards with denominations of 2, 7, 8, 9, and Ace are neutral and have a count value of 0. Small cards 3, 4, 5, and 6 are detrimental to the player and again have a count value of +1 whereas only the 10s and the face cards are counted as -1.

Things get more complex when one introduces additional count values to certain cards as is the case with multiple-level systems like the Zen Count. This is a level 2 system that was introduced by blackjack authority Arnold Snyder in his 1983 book Blackbelt in Blackjack.

### Systems with Side Counts for Aces

You may have noticed from the previous section that more complex, multi-level systems like the above-mentioned Zen Count enable players to keep a side track of the Aces that have been dealt in addition to keeping a running count.

It makes sense that side counting Aces adds to the level of complexity of the system because you have to keep track of several things simultaneously. However, being able to side-count Aces is very valuable, because the effect of removal of these cards is the most dramatic. The Ace is easily the most valuable card in this game. Without it, there will be no blackjacks to earn you higher payouts of 3 to 2. Thus, side counting Aces allows you to make more accurate decisions for the insurance bet.

## Factors to Consider When Choosing a Counting System

When choosing a system, aspiring card counters should take into consideration several important factors.

These include the system’s playing efficiency (abbreviated as PE), its betting correlation (BC), and the insurance correlation (IC).

It makes sense that your experience level should also impact your decision. If you are an aspiring card counter, it would be best to start with a simpler system that allows you to keep an accurate track of the cards.

### The Betting Correlation

The betting correlation shows players how efficient a given card counting system is when it comes to identifying advantageous betting situations. When the sum total of all possible permutations of the cards that remain to be dealt gives you positive expectation when you play optimally, making a bet also offers you a positive expected value. The higher the betting correlation of a given system, the better. A system with a high betting correlation assigns count values that are very close to the actual effect of removal of the cards.

### The Playing Efficiency

The playing efficiency of a given card counting system tells you how effective this system is when it comes to determining the playing deviations from basic strategy. This is very important for professional blackjack players because a portion of their expected returns comes from departing from basic strategy on the basis of the knowledge they have about the changed composition of the remaining cards.

In other words, the PE serves as a measure of how efficiently a counting system informs you to adjust your strategy in accordance with the undealt cards’ composition. The higher the playing efficiency of the system, the better the results it yields.

### The Insurance Correlation

Another portion of the expected profits of the blackjack players comes from correctly identifying the situations when accepting insurance becomes a positive expectation bet. This obviously happens during high positive counts when the shoe is rich in ten-value cards. The dealer is more likely to have blackjacks under these conditions.

It makes sense that card counting systems that keep side counts of the Aces are more efficient in identifying the situations when the player needs to take insurance. Insurance correlation affects both the betting correlation and the playing efficiency of the systems. Keeping a side-count of the Aces improves the betting correlation because these are the most valuable cards from a betting perspective. At the same time, side-counting Aces leads to a decrease in playing efficiency because these cards can have a value of either 1 or 11.

It also matters what type of tables one is playing since playing efficiency is more important in pitch blackjack while the betting correlation has more value in shoe games. It follows that keeping a side count of the Aces is more important when you play multiple-deck blackjack dealt out of a shoe.

Some players keep side counts of other cards besides the Aces for the purpose of improving their overall playing efficiency. This requires a good deal of experience, practice, and concentration because complexity increases exponentially with each side-count you add. Check the table below for the precise betting correlation, playing efficiency, and insurance correlation of the most commonly used card counting systems.

Counting System System Type Betting Correlation Playing Efficiency Insurance Correlation
Hi-Lo Balanced 0.97 0.51 0.76
Red Seven Unbalanced 0.98 0.54 0.78
K-O Unbalanced 0.98 0.55 0.78
KISS 1 Unbalanced 0.87 0.58 0.81
KISS 2 Unbalanced 0.9 0.62 0.87
KISS 3 Unbalanced 0.97 0.56 0.78
Omega II Balanced 0.92 0.67 0.85
Hi-Opt I and II Balanced 0.88/0.91 0.61/0.67 0.85/0.91
Zen Count Balanced 0.96 0.63 0.85
Wong Halves Balanced 0.99 0.57 0.72