How to Count Cards in Blackjack

Is Card Counting Illegal?

No — card counting is completely legal everywhere in the world. It is not cheating. You are using your brain to track information that is visible to everyone at the table.

However, casinos are private businesses and can refuse service to anyone. If they detect that you are counting cards, they may ask you to stop playing blackjack or leave the casino. They cannot prosecute you.

Online casinos use continuous shuffle machines or auto-shuffle after every round, which makes card counting ineffective in that format.

How Card Counting Works

The principle behind card counting is simple: when the remaining deck is rich in high cards (10s and Aces), the player has an advantage over the dealer. When the deck is rich in low cards, the dealer has an advantage.

Why? Because:
• High cards increase the chance of the dealer busting (dealer must hit on 16 or less)
• High cards increase the chance of getting a natural blackjack (pays 3:2)
• More 10s and Aces benefit player splits and double downs

By tracking whether high or low cards have been played, you can estimate whether the remaining deck favors you or the dealer — and bet accordingly.

The Hi-Lo System — Step by Step

Hi-Lo is the most widely used card counting system. It is balanced (the count starts and ends at zero through a full deck) and powerful enough to give a real edge.

Running Count vs. True Count

Running Count: The raw sum of all +1 and -1 values as cards are played. Start at 0 at the beginning of the shoe.

True Count: The running count adjusted for the number of decks remaining. This normalizes the count across different game formats.

True Count = Running Count ÷ Decks Remaining

Example: Running count of +8 with 4 decks remaining = True Count of +2

Always use the true count to make betting decisions in multi-deck games.

How to Bet with the Count

The count tells you when to increase your bets:

• True count +1 or less: Bet minimum. The edge is neutral or negative.
• True count +2: Slightly increase bet. Small edge for player.
• True count +3: Increase bet further. Solid player advantage.
• True count +4 or higher: Bet maximum allowed. Strong player advantage.

A simple approach: Bet 1 unit at true count below +2, 2 units at +2, 4 units at +3, 8 units at +4+. This is called a 1-2-4-8 spread.

The betting spread (ratio of max bet to min bet) determines your overall advantage. A wider spread earns more but attracts more attention.

Practice Drills

Speed and accuracy are everything. Casinos deal fast and you cannot appear to be counting:

Drill 1 — Single Card: Flip through a full deck one card at a time. Count each card. The final count should be exactly 0 (Hi-Lo is balanced). Time yourself. Goal: under 30 seconds.

Drill 2 — Pairs Cancel: Two cards at a time. If one is +1 and one is -1, say 'cancel' and move on without updating the count. This speeds up your mental arithmetic dramatically.

Drill 3 — Table Noise: Practice while watching TV or listening to music. Casinos are loud and distracting.

Drill 4 — Soft Play: Practice at a kitchen table before risking money. Deal hands to yourself and a simulated dealer while counting the full shoe.

What Edge Does Card Counting Give You?

A basic Hi-Lo counter using a 1-8 betting spread can achieve a player edge of 0.5–1.5% over the casino. This doesn't sound like much, but it is the difference between losing and winning long-term.

Note: This is the average edge over thousands of hours of play. Any single session can still go badly — you need a large bankroll relative to your unit bet (at least 200-300 units) to weather variance.

Professional counters typically play with 300-500 unit bankrolls to survive downswings.

For how card counting applies specifically to live dealer blackjack — including table selection and penetration considerations — see Live Casino Guides' card counting at live tables guide.