Card counting is not possible in online blackjack because each new hand is dealt from complete decks. Today, land casinos have systems in place that make card counting extremely difficult and that nullify the advantage that card counting gives. But towards the end of the last century card counting was the rage, thanks to the MIT Blackjack team. Many blackjack players still want to know what card counting is all about. This article, therefore, provides an elementary overview of card counting.

The objective of card counting is to assess whether there are more high value cards left in the deck or more low value cards. One of the simplest systems for doing this is the High Low System. A value of +1 is allotted to cards with values from 2 to 6; 0 is allotted to cards with values from 7 to 9 and -1 is allotted to cards with values of 10. The ace is allotted 0, because it can take a value of either 1 or 11. With a new set of decks the running count starts with zero. When a card is dealt the player adds the allotted value to the running count. If, at any time the running count is a high positive number it means that more low value cards are in the discard tray and more high value cards are in the shoe.

To correct for the aces a side card count is maintained of the aces. This is slightly more difficult. There is one ace for every thirteen cards. Players track the aces dealt in segments of thirteen cards. If no aces have been dealt in the thirteen card segment there is one excess ace in the shoe and the side card count is increased by 1. If two aces have been dealt in the thirteen card segment there is one short ace in the shoe and the side card count is decreased by 1. This is repeated for every segment of thirteen cards. The side card count is added to the running count.

This sum is an indicator of the disparity between high value cards and low value cards left in the shoe. If there are fewer cards left in the shoe then the blackjack player will be better placed to exploit this information. Hence along with the running count and the side count, players have to count the total number of cards dealt. Using the total numbers of cards in the starting set of decks, the player can then calculate the number of cards left in the shoe. Dividing this by 52 gives the number of decks left in the shoe. If the new shoe has 8 decks, then after 26 cards have been dealt there are seven and a half decks are left. The true count is the sum of the running count and the side count divided by the number of decks left.

Whenever the player has to make his ante wager or a move after the hands have been dealt he must know the true count. This will give an idea of how difficult even the simplest blackjack card counting is. The final part of the article qualitatively explains how the true count is used. A high value of the true count indicates that the player is in an advantageous position. Therefore he should wager aggressively. Systems have been devised that link the true count to the wager expressed as a percentage of the player’s bankroll. Also, the blackjack strategy card is modified to include the true count. Instead of stating just “Stand” in a particular cell, it could say “Stand if true count is more than +5, otherwise hit”.