A Guide to Blackjack Card Counting Strategies

Card counting is one of the most popular ways in which players try to reduce the house edge when playing casino blackjack. The basic principles of card counting can be applied in regular casinos, and even when playing for real money online.


As it is a rather difficult strategy to employ requiring concentration and fast counting skills not every blackjack player is able to successfully apply this strategy.

A Guide to Blackjack Card Counting Strategies

One more issue related to card counting is that brick and mortar casinos forbid their players to count cards and ban those who are suspected of dong it. Although card counting is not against the law, casinos have the right to suspend players who they believe are counting cards.

The Principle of Counting Cards in Blackjack Games

The main idea of card counting is to follow the cards that are dealt on the table and track the moment when the cards left in the deck are most favorable. When this occurs, you would increase your bet with improved odds of winning big.

As soon as the cards in the deck are no longer favorable you shouldreduce the bets you’re making and continue to play low stakes until the player edge rises again. However, such large bet size variations are how casinos detect card counters and therefore are one of the major disadvantages.

But before diving into the disadvantages of card counting, let’s get into how you can detect player edge when counting cards!

The Principle of Counting Cards in Blackjack Games

When Do You Have the Advantage Against the Blackjack Dealer?

The player gains an advantage when the number of high cards in the deck is higher than the number of low cards. The idea is that high cards, aces and ten-valued cards, are good for the player and the more of these cards there are in the deck the higher is the player advantage.

On the other hand, low cards like 2s, 3s etc. are better for the dealer. Low cards usually result in stiff hands which the dealer must always hit and a ten will always bust a stiff hand.

Wait, What are Stiff Blackjack Hands?

Stiff hands are hard totals ranging from 12 to 16. It's good for the player if the dealer has such a hand because any ten-valued card will bust a stiff hand. It's especially good for the player who's counting cards and knows when there is a high number of 10s in the deck.

Whereas for the player a stiff hand is not a treat. According to the basic strategy the player should stand on stiff hands from 13 to 16 when the dealer has any card from 2 to 6 as their open card.

Another tip:

It is also a good decision to surrender with hard 16 if the dealer has anything between a 9 and an Ace as their open card as there's a very high possibility of losing the hand.

Blackjack Card Counting Systems You Should Know

There are many card counting systems in blackjack, and the main principle of counting is not memorizing all the cards that are dealt on the table, but rather assigning a specific value to a range of cards and keep count according to the chosen system.

Blackjack Card Counting Systems You Should Know

For example:

One of the most popular card counting systems is Hi-Lo, which assigns positive value (+1) to all cards in the range from 2 to 6 and a negative value (-1) to the range from 10 to A. Cards ranging from 7 to 9 do not affect the count and therefore have a value of 0.

The player counts cards by adding and subtracting numbers according to each card value. When the count number is high enough, meaning that most of the low cards have already been dealt, the player's advantage increases and higher bets can be placed.


This is only a simplified explanation of how the cards are being counted, the actual process is a bit more complicated. Some more advanced card counting systems use values of +2 and -2 or even +5.

As most of the card counting systems require concentration, quick reactions and very good counting abilities, not all players are able to successfully employ them during the game. On the other hand, they are not as difficult as people usually believe they are because of the way card counting is depicted in movies and television.

A very important things to keep in mind when card counting is that even when the count is high and the player's advantage increases, your chances of winning a hand is still below 50%!

More Blackjack Card Counting Techniques

More Blackjack Card Counting Techniques

Besides the way of counting cards that has already been discussed, when a single player is counting cards while playing at blackjack table and increases and reduces their bets according to the player's edge, there are some other ways too.

Card Counting Technique #1: Back-Counting

One of them is known as back-counting or Wonging, since the technique was first introduced by Stanford Wong. When using this technique, the player stands behind the blackjack table and counts cards while other people are playing.

The back-counter only enters the game when they may take advantage of a high player edge. This way the player only bets when they know they have a significantly high chance of winning the hand and does not play when the game favors the casino. This minimizes the player's financial losses.

Although it might look tempting to employ such way of card counting as it enables the player to forfeit all the gameplay when the casino edge is high and the possibility of winning is much lower, it also has some disadvantages.

The major one is that it is very easy for a casino to spot a back-counter as they hop in and out of the game and usually win huge bets. Such players may also annoy the others sitting at the table and draw undesired attention.

Card Counting Technique #2: Group Counting

Group counting is a technique where a group of several people count cards at different tables. By working together these people can increase the player advantage even more and win with higher odds against the house.

In a team of card counters every member has their role; spotters are the ones who play at the tables and count cards while placing minimum bets.

Card Counting Technique #2: Group Counting

As soon as the count is favorable the player, the spotter would delicately send a signal to the big player who would then sit at the table to play big bets and win a lot of money. When the count drops, such player would leave the table and go to the other one which is “hot” at that moment.

The major advantage of group counting is that the players may observe several tables at a time and keep multiple counts whereas a single player can only count one table.

Moreover, the spotters do not even necessarily have to play, they may easily observe the table from the sidelines and signal the big player when the count is high so they would join the table.

But beware:

A group of players observing different tables might draw casino's suspicion as blackjack is not considered to be a game for the audience.

The most well-known case of blackjack group counting was the MIT Blackjack Team: a group of Massachusetts and Harvard students who beat a number of Vegas casinos among others and won huge sums of money.

The story of the team was later told in Ben Mezrich's best-selling book “Bringing Down the House” which was then taken to the big screen in a blockbuster movie titled “21”.

How to Avoid Casino Countermeasures Against Card Counting

Although card counting is completely legal and legitimate blackjack strategy, most of the brick and mortar casinos perceive it as cheating and ban card counters from playing blackjack or entering the casino at all.

How to Avoid Casino Countermeasures Against Card Counting

There were some cases of card counters taking the issue to the court and proving their right to count cards. However, as casinos are privately owned enterprises they are free to set their own rules on what is allowed and what is not within the casino.

Modern casinos have plenty of ways on how to detect card counters. “The eye in the sky” (video cameras installed in the casino ceiling to observe the tables) is a regular security measure applied by most of the brick and mortar casinos which help the surveillance staff spot the “cheaters”.

Casinos nowadays use additional technology to prevent blackjack players from counting cards. For example, they can analyze each player's behavior and playing patterns and match them with those employed by card counters using surveillance software.

Regular players tend to make simple strategy mistakes whereas counters must stick to the basic strategy. They must also increase their bets when the deck is “hot” whereas normal players don't usually do that.

The software keeps track of the cards while following the playing patterns on the table. If the player sticks to the card counter's play, the system alerts the casino and the player is removed.

Counting Cards While Playing Online Blackjack

Land based casinos are not a perfect place for learning how to count cards, but online casinos are. While playing blackjack you’re free to employ any card counting strategy as well as play the basic strategy by using blackjack cards.

Counting Cards While Playing Online Blackjack

Playing at an online casino is a good way to practice card counting and, of course, take advantage of the player's edge. And while brick and mortar casinos use technology to track players who count cards and ban them, the online casinos do not such thing.

You are free to play any way you want and take advantage of the player's edge. Do keep in mind that online blackjack games use a Random Number Generator to shuffle the deck after every play, making it even more challenging to keep track than during regular games.