Table of Contents
What is Card Counting?
In blackjack, the casino holds a very small edge even when a player uses optimal basic strategy. Card counting is a technique that can tip this small edge in the player's favour by using all available information about the cards already dealt.
Unlike all other casino games, blackjack has a past and a future. The cards dealt in previous rounds directly affect the odds of future rounds — because cards are not replaced into the shoe after being dealt. Card counting exploits this by tracking the ratio of high to low cards remaining in the deck.
Key insight: A shoe rich in high cards (10s and Aces) favours the player. A shoe rich in low cards favours the dealer. Card counting tells you which situation you are in — and you adjust your bets accordingly.
The Hi-Lo System Explained
The Hi-Lo system is the most popular and beginner-friendly card counting method. Every card that is dealt is assigned a value of +1, 0, or -1. You keep a running mental total as the cards appear.
| Cards 2 – 6 | +1 ADD one to the running count | Low cards — good for dealer, bad for player |
|---|---|---|
| Cards 7 – 9 | 0 Running count stays the same | Neutral cards — no significant impact |
| Cards 10 – Ace | −1 SUBTRACT one from the running count | High cards — good for player, bad for dealer |
Why does this work? When low cards leave the deck, the remaining shoe becomes richer in high cards — favouring the player. The running count tracks this shift. A positive count means more high cards remain; a negative count means more low cards remain.
The Running Count
The running count is the simple total of all the +1, 0, and −1 values assigned to every card you have seen since the last shuffle. Here is an example sequence:
You continue updating the running count for every card dealt — to all players and the dealer — until the deck is shuffled. The running count resets to zero with each new shoe.
The True Count
The running count alone has a limitation: it does not account for how many decks remain in the shoe. A running count of +6 means something very different with 6 decks remaining versus 1 deck remaining.
The true count normalises the running count by dividing it by the number of decks remaining in the shoe, giving a much more accurate picture of your actual advantage.
The true count is the number you should use to make betting and strategy decisions. A true count of +2 or higher generally indicates a player-favourable shoe; below 0 indicates a dealer-favourable shoe.
Interactive Hi-Lo Practice Counter
Practice the Hi-Lo system with this interactive tool. Click each card as it is dealt and watch the running count, true count, and betting advice update in real time.
Hi-Lo Card Counter
Click cards as they are dealt. Decks remaining updates automatically.
Click a card value to deal it:
Using the Count to Your Advantage
A shoe containing many high cards (10s and Aces) is favourable to the player because it increases the chance of natural blackjacks, and because the dealer — who must hit on 16 or less — is more likely to bust when drawing high cards.
The core strategy is simple: bet small when the count is unfavourable, bet more when the count is favourable. Even with a very high count, the player advantage remains small — around 1% — so disciplined bankroll management is essential.
| True Count | Player Edge | Recommended Bet |
|---|---|---|
| Below 0 | Dealer favoured | Minimum bet |
| 0 to +1 | Roughly even | Minimum bet |
| +2 to +3 | Slight player edge | 2× minimum |
| +4 to +5 | Moderate player edge | 4× minimum |
| +6 and above | Strong player edge (~1%) | 8× minimum |
Important: Even at a true count of +6, the player advantage is only around 1%. Card counting is a long-term strategy that requires hundreds of hours of play and a large bankroll to absorb variance. It is not a get-rich-quick method.
Is Card Counting Legal in Canada?
Card counting is entirely legal in Canada. It is not cheating — it is simply using your memory and mental arithmetic to make better decisions. No law prohibits it.
However, casinos are private businesses and reserve the right to refuse service to anyone. Land-based casinos in Ontario, BC, and Alberta actively watch for card counters and may ask suspected counters to stop playing blackjack or leave the premises.
At online casinos, card counting is effectively impossible in standard RNG (random number generator) blackjack because the deck is reshuffled after every hand. However, live dealer blackjack games use real cards and real shoes, making a form of counting theoretically possible — though most live tables use continuous shuffle machines or shuffle with 50–75% penetration, which significantly reduces any counting edge.
Canadian player tip: Focus on mastering basic strategy first. It reduces the house edge to ~0.5% with no risk of being asked to leave. Card counting is an advanced skill best applied in live dealer settings at reputable Canadian online casinos.