How to Count Cards in Blackjack

Now, you may have heard that counting cards is bad and can get you into a world of trouble – if the movies or popular media have anything to say about it. In truth, there’s no way around it: if you’re trying to figure out how to win at blackjack, you have to combine basic strategy with card counting. When experts play blackjack, they lose more hands than they win, but by counting cards, they know when to increase their bet sizes and when to scale back, so as to make a profit in the long run. Despite the complex depiction of card counting in movies, the technique is fairly straightforward but requires many hours to make it profitable. If you can do basic adding and subtracting in a fast-paced environment, you can count cards.

How to Count Cards in Blackjack | Card Counting Guide

What is Counting Cards?

Card counting is a method that tracks cards that have been played and adjusts blackjack strategy according to which cards remain in the shoe. When playing blackjack, every time a card is removed from the deck, the odds change. If an Ace gets played, there’s one fewer Ace left in the deck. When counting cards, your strategy will be altered in two ways. First, you’ll know when to deviate from basic strategy. Second, you’ll know when to bet more money and when to bet less money. Knowing what cards are coming up in the deck is crucial for both of these advantage plays.

Fortunately, you don’t need to memorize every card that passes through the table to count cards. Card counting groups cards into categories based on how they influence the odds. A deck full of 10-point card values and Aces favor the Player because you have a higher chance of landing a 3-2 payout from getting a Blackjack. Alternatively, a deck full of low-value cards favor the Dealer. 

What is Counting Cards - Ignition Casino

Each category is assigned a positive, negative or neutral number. Counting simply involves adding and subtracting these numbers as the cards pass through the table; this is called calculating the running count. If the remaining deck has a disproportionally high number of Dealer-friendly cards, the running count will be high and you should bet low. If the deck has a high number of Player-friendly cards, the count will be low and you should bet more. 

If you’re playing with more than one deck, you’ll need to take an additional step to establish the true count. If an Ace is played (and thus removed from the shoe) in a game of Single Deck Blackjack, there are only three remaining. This has a big impact on the following rounds. Compare that to the same scenario but with a six-deck variant, where 23 more Aces will be in the shoe, and you can see the difference in impact. To figure out the true count, divide the running count by your estimate of the remaining decks in the shoe. 

 

Is Counting Cards legal?

There are no laws against card counting in casinos. That being said, casinos reserve the right to refuse service to patrons they feel are abusing the system, and they often lump blackjack card counters in that group. The casino staff may ask card counters to leave the table or even the premises, but no legal ramifications will occur.

 

How did MIT "Bring Down the House"?

The MIT Blackjack team was a group of students and professors who used a combination of basic strategy, card counting, and team play techniques to gain a 2%-4% advantage on the house in the 80’s. They were backed by investors and ran their organization like a business.

The idea of team play came from Al Francesco, one of the original seven people inducted into the Blackjack Hall of Fame. He created a team of 10 players, with each player having one of two roles. There were nine scouts who’d sit at various blackjack tables and bet the minimum while tallying the running count. When the deck became Player-friendly, the scouts would signal the 10th team member, the Big Player, to take a seat at their table. The Big Player would sit down and pretend to be a rich tourist learning the game. Thanks to elaborate backstories, the Big Player managed to evade detection while making big bets with shoes rich with Tens and Aces. 

 

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Overview of Card Counting Systems

There are many card counting systems out there, and each system categorizes cards somewhat uniquely. The systems vary in terms of accuracy and ease of learning. Most beginner card counters use the Hi-Lo system, which strikes a good balance between simplicity and effectiveness.
 

Hi-Lo Card Counting

There are three categories in the Hi-Lo system: –1, 0, and +1. Each category represents a value. See below for which cards are assigned which values.

Two: +1
Three: +1
Four: +1
Five: +1
Six: +1

Seven: 0
Eight: 0
Nine: 0 

Ten: –1
Aces: –1

To calculate the running count, simply add 1 for cards Two to Six, and subtract 1 for Tens and Aces. Don’t add or subtract anything for Seven to Nines.

As an example, if you have a Six (+1), Two (+1) and Nine (0) in your hand and the Dealer has a Ten (–1) and Eight (0), the running count is +1.

 

K-O (Knock Out) Card Counting

The K-O system is similar to the Hi-Lo system, except that Sevens are part of the +1 category, and you don’t need to divide the running count into a true count. See below for the three categories used in the K-O system.

Two: +1
Three: +1
Four: +1
Five: +1
Six: +1
Seven: +1

Eight: 0
Nine: 0 

Ten: –1
Aces: –1

To get around having to calculate the true count when using the K-O system, you start the running count at different values depending on the number of decks you’re playing with. 

One Deck: Start Running Count at 0
Two Decks: Start Running Count at –4
Six Decks: Start Running Count at –20
Eight Decks: Start Running Count at –28

For the K-O, simply bet more when the count is positive, and bet the minimum when the count is negative.

 

Red Seven Card Counting

The Red Seven is the same as the Hi-Lo and K-O system except the 7 is assigned a 0 or a +1 depending on the color (hence Red Seven). There’s no need to divide the running count into a true count when using the Red Seven system.

Card Counting Systems - Ignition Casino

Two: +1
Three: +1
Four: +1
Five: +1
Six: +1
Red Seven: +1

Black Seven: 0
Eight: 0
Nine: 0 

Ten: –1
Aces: –1

One Deck: Start Running Count at –2
Two Decks: Start Running Count at –4
Six Decks: Start Running Count at –12
Eight Decks: Start Running Count at –16

 

Omega II Card Counting

The Omega II system is more advanced than most systems, as it has multi-levels (–2 to +2) and works best with a side count of Aces. The benefit for the added complexity is a system that’s more accurate and effective than the others mentioned in this post (with the exception of the Wong Halves method). The five categories for the Omega II system are as follows:  

Two: +1
Three: +1
Seven: +1


Four: +2
Five: +2
Six: +2

Eight: 0
Aces: 0

Nine: –1

Ten: –2

 

Wong Haves Card Counting

Out of all the betting systems we’re covering, the Wong Haves system is the best for determining when you should increase your bet sizes. It’s also the most complicated system out there and is rarely used by card counters.

Two: +0.5
Seven: +0.5

Three: +1
Four: +1 
Six: +1

Eight: 0

Nine: –0.5

Ace: –1
Ten: –1

 

Benefits and Risks of Counting Cards - Ignition Casino

Benefits and Risks of Card Counting

Expected Edge of Card Counting

The edge received from card counting depends on the system you’re using. The Omega II has the lowest betting correlation (92%) and the Wong Haves has the highest at 99%. The edge ranges from 0.5-1.5%.

 

Casino Detection of Card Counting

Casino personnel are trained to detect card counters and alert the pit boss when they spot one, so you want to look like a casual player who doesn’t count cards. Detection comes from players greatly increasing their bet size after a lot of low-ranking cards are played through; however, that’s also the fastest way to make a profit. You need to find a balance between increasing your payouts while not making it too obvious. 

 

Casino Treatment of Card Counters

Maybe it was different in the ‘60s, but nowadays, casino personnel won’t rough up card counters in the back room. There are too many lawsuits for that. They’ll either re-shuffle the entire deck or ask you to leave. They can also bar you from coming back in the future.

If you think card counting is for you, you should only attempt it after mastering basic blackjack strategy. There’s no substitute for practicing your strategy, so hop on to one of our nine blackjack games and start honing your skills on Practice Play mode. The next step is learning the Hi-Lo method. Good luck at the tables.