There is no one definitive card counting system for blackjack. Different players prefer different systems, and the best system for one player may not be the best system for another.
Some common card counting strategies include using basic strategy, counting down, and running count.
Basic strategy is the simplest form of card counting, and involves playing the same basic way regardless of the dealer’s hand. This allows you to minimize your chances of getting unlucky and winning more money than you would have if you were playing randomly.
Counting down is a strategy that involves reducing your bet by one unit each time the dealer hits a soft 17 or blackjack. This can help you avoid getting too aggressive with your hand, and also gives you a better chance of hitting a soft 17 if you do get into a hand where this is an option.
Running count is a more advanced form of card counting that involves keeping track of both the number of decks being used and the number of cards remaining in each deck. This allows you to make bets based on what you believe to be the most advantageous combination of cards remaining in each deck.