What is Card Counting?
Card counting is a blackjack strategy that allows players to track the ratio of high to low cards remaining in the deck. When the deck is rich in high cards (10s, face cards, and Aces), players have a statistical advantage and should bet more. When the deck is rich in low cards, the advantage shifts to the dealer.
Card counting is 100% legal. You’re simply using your brain to track information—no devices, no team signals, just mental arithmetic. Casinos don’t like it, but there’s nothing illegal about being smart at the blackjack table.
The Hi-Lo Counting System
The Hi-Lo system is the most popular card counting method for good reason: it’s simple to learn yet powerful enough to give you a real edge. Here’s how it works:
Hi-Lo Count Values
| Card | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | J | Q | K | A |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Value | +1 | +1 | +1 | +1 | +1 | 0 | 0 | 0 | -1 | -1 | -1 | -1 | -1 |
How to Use These Values
Start with a count of zero when a new shoe begins. As each card is dealt, add or subtract according to its value. This “running count” tells you whether the remaining deck favors you or the casino.
For example, if the first few cards are: 5, 10, 3, King, 7, 2
Your count would be: +1 -1 +1 -1 +0 +1 = +1
A positive count means more low cards have been played, leaving the deck rich in high cards—favorable for the player.
Running Count vs. True Count
The running count tells part of the story, but in multi-deck games, you need the true count to make accurate betting decisions.
True Count = Running Count ÷ Decks Remaining
If your running count is +6 with 2 decks remaining, your true count is +3.
The true count is what actually determines your edge and bet size. A true count of +1 means roughly a 0.5% player advantage; +2 means about 1%, and so on.
Betting Strategy
Your bet spread depends on your bankroll, risk tolerance, and the game conditions. A common approach:
- True Count ≤ 0: Minimum bet (1 unit)
- True Count +1: 2 units
- True Count +2: 4 units
- True Count +3: 8 units
- True Count +4+: 12-16 units (max bet)
This 1-16 spread is aggressive. Many counters use a more conservative 1-8 spread to reduce variance and avoid detection.
Playing Deviations
Beyond betting, card counters also deviate from basic strategy based on the count. The “Illustrious 18” are the most important deviations:
- Insurance: Take at +3 or higher
- 16 vs 10: Stand at +0 or higher
- 15 vs 10: Stand at +4 or higher
- 10 vs 10: Double at +4 or higher
- 12 vs 3: Stand at +2 or higher
- 12 vs 2: Stand at +3 or higher
Deck Penetration
Deck penetration refers to how many cards are dealt before shuffling. The deeper the penetration, the more profitable counting becomes.
- 75%+ penetration: Excellent, worth playing
- 65-75% penetration: Good, playable with a larger spread
- Below 65%: Marginal, consider finding a better game
Bankroll Requirements
Card counting requires a substantial bankroll to weather the variance. Common recommendations:
- Aggressive (5% risk of ruin): 200 max bets
- Moderate (1% risk of ruin): 500 max bets
- Conservative (0.1% risk of ruin): 1000 max bets
If your max bet is $100, a conservative bankroll would be $100,000.
Practice Makes Perfect
Before hitting the casino, you need to be able to count accurately and quickly without conscious effort. Use our free trainer to build your skills:
Quick Practice
Test your counting skills
Hi-Lo SystemFrequently Asked Questions
Is card counting illegal?
No. Card counting is completely legal. You’re using your brain, not any device or outside help. However, casinos are private property and can ask you to leave or refuse your action if they suspect you’re counting.
How long does it take to learn?
Most people can learn the Hi-Lo system in a few days. Becoming proficient enough for casino play typically takes 6-8 weeks of dedicated practice.
How much can I make counting cards?
A skilled counter with a $50,000 bankroll playing full-time might earn $50,000-$75,000 per year. Most recreational counters play part-time with smaller bankrolls and more modest returns.
Will I get banned from casinos?
Eventually, if you’re successful. Casinos track known counters and share information. Many counters use disguises, vary their play, and work in teams to extend their casino lifespan.