You will come across many people who will dispute this blackjack card counting theory, however, it is not a matter of opinion or belief but a matter of fact. It's proven mathematically everyday at the tables. If you can stand on a busy corner, watch the cars go by, add one each time you see a white car, subtract one each time you see a black car, and do nothing each time you see a car of some different color, YOU can learn to count cards. Counting cards is what it will take to become the player that the casino fears most a consistent winner. All counting systems treat some cards as positive and some as negative.
Some counts even use halves.
If one were to count through the deck and, at the end, arrive at zero the count is said to be balanced. The total of all the plus values equals the total of all minus values. Unbalanced counts will end the above experiment with a number other than zero. All counting systems must indicate when you should raise your bet. They do this either by a certain positive count, or a strike value, or even by the calculation of the ratio of the number of remaining non-ten valued cards divided by the number of remaining ten valued cards.