1What card counting is
Card counting is a technique used in blackjack to track whether the remaining deck is rich in high cards (10s and Aces) or low cards (2-6). When the deck is rich in high cards, the player has a statistical advantage over the dealer because blackjacks are more likely and the dealer is more likely to bust.
A skilled card counter can shift the house edge from around 0.5% (with basic strategy) to a player edge of 0.5-1.5%. This is not cheating - it is using your brain - but casinos can and do ban players they suspect of counting.
2The Hi-Lo system
The Hi-Lo system is the most widely used card counting method. Every card is assigned a value of +1, 0, or -1. You keep a running total as cards are dealt.
| Cards | Count value | Meaning |
|---|---|---|
| 2, 3, 4, 5, 6 | +1 | Low cards - count goes up |
| 7, 8, 9 | 0 | Neutral - count unchanged |
| 10, J, Q, K, Ace | -1 | High cards - count goes down |
A high positive count means many low cards have been dealt - the remaining deck is rich in high cards, which favours the player. A negative count means the opposite.
3Practice the running count
The running count is the cumulative total of all card values seen since the last shuffle. Start at zero and add or subtract as each card is revealed.
Example hand:
Cards dealt: 5 (+1), King (-1), 3 (+1), 8 (0), 6 (+1), Ace (-1)
Running count: +1, 0, +1, +1, +2, +1
Final running count: +1 (slightly favourable)
Practice at home with a single deck until you can count through all 52 cards in under 30 seconds without errors. Then practice with distractions - music, conversation - to simulate casino conditions.
4Calculate the true count
The running count alone is not enough in multi-deck games. You need the true count, which accounts for how many decks are left to be dealt.
True count formula:
True Count = Running Count / Decks Remaining
Example: Running count of +6 with 3 decks remaining = True count of +2
A true count of +2 or higher is generally considered favourable. Each +1 in true count shifts the edge by approximately 0.5% towards the player.
5Adjust your bets
The whole point of counting is to bet more when you have the advantage and less when the house has the edge. A typical bet spread for a card counter:
Large bet spreads attract casino attention. Most counters use a 1:4 or 1:8 spread to stay under the radar while still gaining an edge.
6Why it is harder online
Card counting is legal but casinos can ban you. Online RNG blackjack reshuffles after every hand, making counting ineffective.
Online RNG (Random Number Generator) blackjack uses a virtual infinite shoe that reshuffles after every single hand. This makes card counting completely useless because the count resets to zero with every new deal.
Live dealer blackjack online is closer to a real casino - a physical shoe is used and cards are not reshuffled every hand. However, most live dealer tables use 6-8 decks and cut the shoe at 50-60%, limiting the number of countable cards.
Even in live dealer games, online casinos monitor bet patterns electronically and can detect counting far more easily than a pit boss in a physical casino.
7Alternative strategies for online play
Since card counting does not work on RNG blackjack, focus on strategies that do make a difference online:
Perfect basic strategy
Reduces the house edge to 0.5% or less. Use a strategy chart until it is memorised.
Game selection
Choose single-deck or double-deck games where available. Avoid 6:5 blackjack - always play 3:2.
Single-deck games
Single-deck blackjack has the lowest house edge. Look for Classic Blackjack variants.
Avoid side bets
Insurance, Perfect Pairs and 21+3 all carry a much higher house edge than the main game.
Try Classic Blackjack or Blackjack Pro for the best online odds, or practice for free in our free games section.