The 21 Method of "Card Counting"

So as I said earlier, the “card counting” in the movie 21 was completely bogus. Why? For two reasons. First. They were not predicting hands, they were simply predicting the likeliness of hands to come. Second. Their predictions were not on a card by card basis, they were based on quite general things.

What they did in the movie was assigned several different cards (low cards) a positive value, and the same number of others (high cards) negative value (5 of each). When a large amount of low cards passed, a player was signaled to the table. Then they would rake in the cash, but they still have to keep the count. So, what they were doing was not card counting, but simply tracking probability.

This formula is astoundingly simple, and pretty much anyone can do it. Try it yourself, but not at a real casino, because you could get killed.