The Hi-Lo system

Why counting works

Blackjack is unusual: cards already dealt change the odds of what comes next. A shoe rich in tens and aces favors the player (more blackjacks, stronger double-downs, dealer busts more). A shoe rich in low cards favors the house. Card counting tracks that balance with simple arithmetic — no memorizing which cards are gone.

Card values

Hi-Lo assigns every card one of three values:

The count is balanced: a full deck sums to exactly 0. That makes it self-checking — count down a whole deck and you should land on zero.

Running count

Start at 0 when the shoe is shuffled. For every card you see — yours, other players', the dealer's — add its Hi-Lo value. A positive running count means more low cards have left the shoe, so the remaining cards favor you.

True count

A running count of +6 means much more with one deck left than with six. Divide the running count by the number of decks remaining (estimate from the discard tray) and round toward zero:

true count = running count ÷ decks remaining

Example: running count +7 with about 3.5 decks left → 7 ÷ 3.5 = 2 → true count +2.

How to practice

1. Card Countdown — count through a full deck without mistakes, then push your speed. Under 30 seconds for one deck is a common benchmark.
2. True Count — make the division instant and automatic.
3. Table Simulation — hold the count through the noise of a real table, round after round.