Card counting basics
Want to learn how card counting in blackjack works?
Blackjack card counting does not require you to memorise or track specific cards. Instead, players must assign a point score to every card that comes out of the deck. They then track the total of these values over time to ascertain the 'running count'.
The running count helps to determine whether there are more high-value cards or low-value cards remaining in the deck. High-value cards are more beneficial to players than low-value cards, as they create the opportunity for the following:
- A better chance of landing a natural blackjack and thus receiving the bigger blackjack payout
- Double downs on additional hands to improve your potential profits
- More chances to split hands, which the dealer cannot do
- A larger concentration of tens can make it more beneficial to take the insurance bet when the dealer shows an Ace on their up card
If you want to be a good card counter at the blackjack tables, it’s highly recommended that you familiarise yourself with basic blackjack strategy. Most experienced card counters adhere by the basic strategy even while card counting, to maximise their edge over the house.
Speaking of edges, card counting techniques can tip the balance in your favour by between 0.5%-1%. Although this means you are unlikely to get rich quick, your losing streaks are unlikely to be extreme either.
Card counting systems
What is a card counting system?
A card counting system is a defined set of rules that determines how you keep track of the running count of the game and ascertain when the ratio of high cards to low cards is in your favour instead of the dealer’s.
When you are choosing a blackjack card counting system, it’s important to opt for one you are comfortable with. It doesn’t matter whether you choose the simplest or the most complex system. But you'll want to make sure it’s one that you can stick with and suits your abilities at the tables.
Today’s blackjack card counting systems have evolved immensely from the days of Edward O. Thorp’s original system. Below, we’ll take you through ten of the most popular card counting strategies that you could employ at the tables.
Hi-Lo card counting
Arguably the most common card counting strategy in blackjack today, the Hi-Lo system was first developed by a man named Harvey Dubner in the 1960s. It requires you to begin with a running count of zero at the beginning of the deck or shoe. You’ll then assign values to each card that comes out (+1, 0, or -1) to ascertain whether there is an imbalance of high or low-value cards remaining in the deck.
- Low cards (2-6) = +1 Low-value cards require you to add one to the running count. The higher the running count, the more high-value cards there are remaining in the deck.
- Neutral cards (7-9) = 0 Mid-range cards are considered neutral cards in this system. You are not required to add anything to the running count when these are dealt.
- High cards (10-A) = -1 High-value cards require you to subtract one from the running count. The lower the running count, the more low-value cards there are remaining in the deck.
When the running count is high, you should bet more to take advantage of the improved probability of landing natural blackjacks and high-value hands. When the running count is low, you should limit the size of your bets to minimise the damage to your bankroll from losing hands with multiple low-value cards.
Hi-Opt I card counting
Devised by Charles Einstein (no relation to Albert!) back in 1968, the Hi-Opt 1 system has since been enhanced by Carl Cooper and Lance Humble to create an effective card counting system for blackjack.
Hi-Opt 1 is similar to the Hi-Lo strategy in that you are required to build a running count during your gameplay. However, Hi-Opt 1 takes the Hi-Lo strategy a little further by helping create something known as a ‘true count’ alongside the running count. A true count is considered by blackjack professionals to be a more accurate assessment of the cards remaining in the dealer’s deck or shoe.
Hi-Opt II card counting
The Hi-Opt II counting system uses Hi-Opt I as the basis of its strategy whilst implementing alternative point values to try and improve the effectiveness and accuracy of your running count at the table. Hi-Opt II is a more complex system than most, including Hi-Opt I, so might not be best suited for beginners to blackjack card counting.
In Hi-Opt II, there is the addition of a +2 and a -2 point value in the count. Naturally, introducing more values to the counting system can make it harder to maintain an accurate count in action. Below is an outline of the new point values in Hi-Opt II:
- 2-3 = +1
- 4-5 = +2
- 6-7 = +1
- 8-9 = 0
- 10-K = -2
- A = 0
Thorp’s Ten-Count System
As we've touched upon above, the very concept of card counting in blackjack was created by a man named Edward O. Thorp, a maths professor and hedge fund manager by day, and author by night. He pioneered the original card counting theory surrounding single-deck blackjack – the ten-count system.
Thorp’s system requires you to begin a mental count of zero at the start of your game. As the cards are dealt, you are then going to assign each card on the table with a value, regardless of whose hand they belong to. The values are as follows:
- A, 2, 3, 4, 5, 6, 7, 8, 9 = +4
- 10, J, Q K = -9
Once you’ve mastered adding four and subtracting nine from the count, you know how to get a running count. However, the casinos soon cottoned on to Thorp’s system, which was optimised for single-deck blackjack. So, what did the casinos do? They introduced blackjack tables using multiple decks, rendering the system null and void.
KO card counting
The Knock Out (KO) card counting system is an unbalanced card counting system. What do we mean by unbalanced? An unbalanced system is one where the point values for all the cards counted does not add up to zero. A balanced system sees the sum of the count values assigned to each card net out to zero.
Unbalanced systems are a good starting point for beginners who find it difficult to convert the running count into a more accurate true count.
The KO card counting system is similar to the Hi-Lo system, with one major exception. In the KO system, the number seven is considered a low card and a +1 rather than a zero (or neutral) card in Hi-Lo:
- Low cards (2-7) = +1
- Neutral cards (8-9) = 0
- High cards (10-A) = -1
Omega II card counting
The Omega II blackjack counting strategy was the brainchild of Bryce Carlson. The system was very popular in the 1990s and is still sometimes used today. It uses a multi-level points value system, with some card counting values at 2 and others at 1:
- 4, 5, 6 = +2
- 2, 3, 7 = +1
- 8, A = 0
- 9 = -1
- 10-K = -2
Although the Omega II system is considered one of the most accurate blackjack counting practices, giving players a great chance of calculating their position in the game at any given time, its complexity makes it less suitable for newcomers to basic blackjack strategy and card counting. It’s also an unbalanced system like the KO strategy, so you’ll never be able to fully determine the true count of your game.
The Ace/Five count
Those seeking total simplicity and accessibility in their blackjack counting practice should look no further than the Ace/Five count system.
First and foremost, you’ll need to predefine a minimum and maximum bet size for your game. At the start of your game, the running count will be zero. Whenever a five comes out of the deck, add 1 to your running count. Whenever an Ace is dealt from the deck, subtract 1 from the count.
From there, whenever your running count is higher than or equal to 2, you double your previous bet to your maximum wager. If the running count falls to less than or equal to one, you stick to your minimum wager.
This strategy is thought to be the most effective at beating the plethora of casinos that now offer six and even eight-deck blackjack games.
Red Seven card counting
The Red Seven system is another strategy that’s been simplified to suit beginners to blackjack counting strategy. Devised by Arnold Snyder in the early 1980s, it uses the following card counting values:
- 2, 3, 4, 5, 6 = +1
- 7 red = +1
- 7 black = 0
- 8-9 = 0
- 10-A = -1
To begin your count, you’ll need to multiply the number of decks in play by -2. If you’re sat at a six-deck blackjack table, your count will begin from -12. If, over time, your running count reaches a positive figure, you can increase the size of your wager. By multiplying the number of decks from the outset, you are getting a more accurate true count from the word go.
Halves card counting
In terms of complexity, the Wong Halves card counting system is up there with the toughest blackjack counting practices to master. The Halves card counting strategy begins with zero, but the point values differ greatly:
- 3, 4, 5, 6 = +1
- 2, 7 = +0.5
- 8 = 0
- 9 = -0.5
- 10-A = -1
This strategy is one of the most complex but most accurate card counting techniques all the same. It offers a 0.99 betting correlation out of 1.00, allowing players to make confident predictions about the outcome of future cards dealt from the deck. However, the addition of more point-based values can make this system harder to keep on top of in a busy, exciting casino setting.
Zen card counting
Another brainchild of Arnold Snyder, the zen counting system is a balanced strategy that relies heavily on the running count:
- 4, 5, 6 = +2
- 2, 3, 7 = +1
- 8-9 = 0
- A = -1
- 10-K = -2
Alongside the Halves card counting system, the zen strategy is up there as one of the most accurate card counting techniques. It offers a betting correlation of 0.96 out of 1.00, so players can bet confidently in the future outcomes of the game, providing they can calculate the point values quickly and accurately. Accurately is the operative word here, as this complex system means it’s all too easy to lose your train of thought amidst the buzz of the casino floor.