Counting cards is a one more strategy, which is very useful when you play blackjack. That way the player will have the edge over the house. The advantage gained is so huge and that's why it is always spotted really fast by the casino's authorities. In most cases you will be banned forever, if you get caught counting cards. The basic card count strategy includes the counting of low and high cards.
Card's value is counted, whey you do the "running count". When you use a Hi/Lo system for example, this running count becomes "true count". This modification is required because more than one deck is used in the game. You need to know how many decks have not been used in the game yet.
This is essential to the strategy. Also, you need to estimate the cards, which have been dealt each round. There are many different kinds of true count systems, which you can easily find.
The players who have examined the deck will know when they will have the advantage. This is the point where they "Wong in" the game. The player could modify the strategy to increase/decrease his bets depending on the count card. If the deck is shuffled, the player could "Wong out" and leaves the table. Many players prefer to play till the point where their advantage is gone. This is the safer option. Back- counting is carried on in games where the presence of 4, 6 or even 8 decks is necessary. The reason for that is simple. This card counting strategy works better when more than one deck is used.