How to Count Cards in Blackjack

What counting actually is

Card counting is not memorizing the deck and it is not a trick. It is one running tally that tracks whether the cards remaining in the shoe are rich or poor in tens and aces. When the remainder is rich in big cards, the player's chances improve — blackjacks pay more than they cost, doubles connect more often, the dealer busts more. Counting simply tells you when that is true, so you can bet more then and less otherwise.

That is the entire idea. Everything else — systems, conversions, deviations, camouflage — is engineering around that one fact.

The Hi-Lo values

Hi-Lo assigns every card one of three values: 2 through 6 count +1, 7 through 9 count 0, and tens, faces, and aces count −1. As each card leaves the shoe you add its value to a running count. Low cards leaving is good for you — they were the dealer's friends — so the count rises. Big cards leaving is bad for you, so it falls.

A positive running count means the shoe that remains is richer in big cards than normal. That is the signal.

From running count to decision

In a multi-deck game the raw running count overstates itself — a +6 with five decks left is thinner than a +6 with two decks left. So you convert it: divide the running count by the number of decks you estimate remain. The result, the true count, is the number that actually drives your bets. Our guide on the true count walks the whole conversion, including the deck estimation that makes it honest.

How you actually learn it

You learn to count the way you learn an instrument: a small skill drilled until it stops costing attention. Deal a deck one card at a time and keep the tally; a counted-out deck ends at exactly zero, so the deck grades you honestly every run. Then add a clock. Then add pairs. Then add noise. The free countdown drill on this site runs that exact ladder and times you, which is the part self-dealt cards can't do.

Questions

Do you have to be a genius to count cards?

No. Hi-Lo is adding one, subtracting one, and dividing small numbers. The hard part is doing it fast, quietly, for hours — that is training, not talent.

How long does it take to learn?

Counting a deck down cleanly takes most people days. Doing it at casino speed under distraction takes weeks of honest drilling. There is no shortcut that survives a real table.