Card counting is one of the better known ways of beating the house it is one of the most difficult. The basic premise is that the counter keeps track of what cards have been dealt out of the shoe and uses this information to base his decisions on.

Card counting is not as accurate as many people believe, as you do not know what card is going to be dealt next you just keep track on whether the deck is favourable. You can do this by keeping track of the amount of high cards to low cards that have been dealt. If very few high cards have been dealt in the first half of the shoe then the deck could be described as favourable. High cards are 10's face cards and aces. It is easier to keep track of cards that score ten, as they are the most plentiful cards in the deck.

There are three main reasons that decks high in face cards are favourable to the counter and not the casino.

Firstly, the higher the proportion of tens and aces in the deck then the higher the likelihood that you can get a blackjack. It is true that the dealer is more likely to pull a blackjack as well. However when the dealer is dealt a blackjack you lose all your wager when you are dealt a blackjack you win 3 to 2 so you get 150% of your wager and lose only 100%. If you and the dealer trade blackjacks at the end you will be up.

The dealer must draw when he has a 16 or less. He has no choice. When the deck is favourable, he runs a greater risk of busting. You, on the other hand, can alter your strategy to take advantage of favourable conditions. You don't have to take a card when the odds of busting are great because of a favourable deck.

With doubling down on 10 and eleven with a favourable deck it is very valuable as the odds of the next card being a ten or ace is quite high which gives you a very high hand at double your initial wager.