Indeed, early in the game, each card is represented four times (one heart, one in spades, diamond and a club) per pack of cards (since most tables use 3 to 8 decks).
Progressively during the distribution, certain cards are found consistently less represented than others in the shoe.
According to the cards that were drawn, it is then possible to determine which ones remain.
Based on this information, you can know if the shoe is to your advantage or the dealer.
The whole point of card counting is precisely to determine the cards remaining to be distributed.
With high value cards When the shoe contains many high value cards, the player has an advantage.
In fact, the dealer can not play as he sees fit.
Instead, he must follow a strict rule which is to stop when his hand reaches a certain value, 17 in general.
He will therefore automatically draw a card even if his hand is relatively high (between 14 and 16), which should make him frequently exceed 21.
It is in these moments where you have to increase your bets because you have higher chances of winning.
With cards with low values But, when the shoe has more low cards, you are disadvantaged.
In effect, the dealer will burn less often and you rarely get a black jack.
In those moments, it is advisable to decrease your bets or even leave the table.
Very effective card counting allows you to have a house advantage of less than zero, which means that the game is to your advantage.
Thus, it is strongly advised to learn this strategy very attractive for the player.