Blackjack Card Counting in Practice

Mathematician Edward O. Thorp in his 1962 book Beat the Dealer was the first to expose to the world a card counting system that worked. His book is now regarded a classic in gambling literature but the system that he devised in it is no longer applicable (in some parts) because of changes made by the casinos throughout the years. The changes to in-house casino rules where a direct response to Thorp’s book and an unmistakable proof that they worked. As you can surely understand, his card counting theories were a success and casinos were starting to lose money to anyone with enough wit and dedication to understand his blackjack systems. Fortunately, the core blackjack rules didn’t change, and we can still devise profitable systems by relying on Thorp’s earlier work.

The basis for his system however, is still used in most of the counting systems developed to date. Since for the average human remembering every card that has left the deck is no small chore, a basic counting scheme assigns values of positive or negative numbers to the cards (and derived from that to the entire deck) in order to facilitate the count.

The system described below will use this point system according to this table:

Aces and 10’s (including all face cards) are good for the player. This means that if many aces and 10’s have left the deck, it has negative value for the player. The opposite goes to cards 2-6. Cards 7-9 have a small effect on the outcome for the player so they have no value assigned to them.

So you start counting the cards and after ten cards have been dealt your count is at minus 2. What should you do? -2 means that this deck puts you at a slight disadvantage versus the house. Of course, the easiest thing to do would be not to bet at all when the deck has a negative value, however this will quickly expose you as a card counter and you will probably be thrown out of the casino in no time. What you should do is change your betting amounts in order to lose the least possible when you are at a disadvantage. If the deck has a positive value you should increase your betting amount because you have better chances to beat the dealer. The following table will show the increments in which you should change your betting units:

As mentioned before, if the count is negative you should try to minimize the damages by betting the least without drawing attention to yourself as a card counter.

If you are playing in game with more than one deck you will have a little bit more work to do in order to apply the betting variation table. You need to look at the cards that are yet to be dealt and evaluate how many decks are left, you than divide your running count by that number. The result is called the “true count” and you should use this value to determine your betting amount according to the table above.