Cards values according to Hi-Lo method:

2, 3, 4, 5, 6 --> +1

7, 8, 9        --> 0  

10, J, Q, K, A --> -1

The player is exposed to calculation of the present value of his cards in every stage. Let us see how it works, when 15 cards are dealt.

The example above shows that player’s chances improve with every new card given by the dealer. After the fifteenth card the present value amounts to +6 – is a huge advantage? It depends how many decks the croupier uses, how many decks are still to be dealt. Common sense says that the more decks are still in croupier hands the worse for the player. For example, if the dealer still has seven decks to deal, the player has only a minimal advantage. However, if he is left only with a singe deck the player’s advantage is huge.

Professionals playing blackjack require more details about decks left. They rely on so called true value, which is a result of dividing the present value by the number of decks left. For example: if the present value is 8 and there are 4 decks left, then the true value is 2.

If you sure about your advantage you should use this fact to turn this advantage in the money. How to do it? It seems to be quite easy, but it is not. When the advantage lies on the casino side, you put in bet the minimum required and when you have the advantage, you put more in the bet. It is important not to play too risky, because the probability that you loose is still positive. How to reconcile the greed with the needed caution? The best solution is applying so called Kelly’s criterion- mathematical formula that tells what percentage of your capital should be invested in a certain stage in game. Without applying complicated mathematical calculations, the strategy looks like follows: you invest 1% of your capital in order to gain a 1% advantage over the casino. If you have $10,000 and after an hour in a game, your advantage over casino has increased to 3%, then you should bet another $300 in every stage.

Development of the computer technology allows players carrying out million of simulations that further allow cards counting at much higher speed than ever before. Those methods are much more efficient and more accurate than Hi-Lo Count method. However, those methods are not easy to understand for a simple player. Besides casinos do their best to make counting cards difficult for all blackjack players. Although cards counting is a legal procedure casinos try to discourage players from using this method by, simply, not playing with them.

However, it does not mean that you cannot make a fortune on blackjack. Yes, you can! If you want to play professionally 21, you should have a look at great documental movies about eternal war between players and casinos. Although that are not Hollywood movies they present a very accurate picture of relation between those two parts.