Card Counting Explained: How It Works and Why Casinos Hate It

What is Card Counting?

Card counting is a blackjack strategy that tracks the ratio of high cards to low cards remaining in the deck. When the remaining deck is rich in high cards (10s, face cards, Aces), the player has an advantage.

Why It Works

High cards benefit the player because:

1. Blackjack pays 3:2 — More 10s and Aces = more blackjacks
2. Dealer must hit to 17 — High cards make the dealer bust more often
3. Better doubling opportunities — More 10s mean better doubles on 10 and 11

The Hi-Lo System

The most popular counting system assigns values:

Running Count → True Count

• Running count: Sum of all card values seen
• True count: Running count ÷ decks remaining
• True count of +2 or higher = player advantage

The Edge

Why It's Harder Than It Looks

1. The edge is tiny — Average advantage is only 0.5-1.5%
2. Massive variance — You can lose for weeks despite counting perfectly
3. Casino countermeasures — Frequent shuffling, multiple decks, back-offs
4. Bankroll requirements — Need 200-400 max bets to survive variance
5. It's boring — Hours of grinding for small edges

Legal Status

Card counting is legal — it's using your brain, not a device. However, casinos are private property and can ask you to leave or ban you from playing blackjack. They cannot confiscate your chips.

Is It Worth It?

For most people, no. The hourly rate for a skilled counter at a $25 table is roughly $25-50/hour — before expenses, travel, and the stress of potential back-offs. But understanding how it works teaches you valuable lessons about edge, variance, and bankroll management.