Card Counting
Card counting tracks the ratio of high to low cards remaining in a blackjack shoe to bet more when the odds favour the player. It is legal but actively countered by casinos, hard to do profitably, and impossible against online RNG blackjack.
| Idea | Track high vs low cards remaining |
|---|---|
| Legality | Legal, but casinos can refuse service |
| Effect | Can swing the edge slightly to the player |
| Online Rng | Does not work (deck reshuffles each hand) |
How counting works
A shoe rich in tens and aces favours the player (more blackjacks and strong doubles), while one rich in low cards favours the dealer. Counters assign +1/-1 values to cards to keep a running tally, raising their bets when the count is high. Done well, this can shift the edge a fraction of a percent in the player’s favour over basic strategy.
Why it is harder than it sounds
Counting is legal — you are only thinking — but casinos are private businesses and routinely counter it with frequent shuffles, multiple decks, betting-pattern surveillance, and barring suspected counters. It also requires discipline, a sizeable bankroll to ride the variance, and favourable rules. Crucially, it is useless online against RNG blackjack, where the deck is effectively reshuffled every hand.
Frequently asked questions
Is card counting illegal?
No, it is legal — it is mental skill, not cheating. But casinos may refuse service to or bar suspected counters.
Can I count cards at an online casino?
Not against standard RNG blackjack, which reshuffles each hand. It only applies where a physical or live shoe is dealt deep before shuffling.
Sources
- Blackjack mathematics literature
- Published game rules