Card Counting in Blackjack
Films such as 21 and The Last Casino have brought card counting to many people’s attention. The technique is best known in blackjack: players track cards that have been dealt to estimate whether the remaining cards may favor the player or dealer. The house generally has a strategic edge, but careful play can shift the odds toward the player. Card counting may improve the chance of ending ahead, but it can’t guarantee a win.
How Card Counting Works
Blackjack may be dealt from one deck or several, depending on the game. As cards leave play during each hand, tracking certain cards can help you estimate what remains. Card counting is the practice of keeping that tally as the dealer works through the shoe.
The basic counting method follows these steps:
1. Give Each Card a Value
You don’t need a photographic memory to count cards. Many players use a tagging system: assign a number to each card, then add to or subtract from a running total as cards appear on the table.
Hi-Lo is a popular, relatively straightforward counting system. It gives each card a value of -1, 1 or 0. In a 52-card deck, the values add up to zero. The card groups are scored as follows:
- Cards 2-6: 1
- Cards 7-9: 0
- Cards 10-Ace: -1
2. Keep a Running Count
As each card is dealt, update the total by adding 1, subtracting 1 or leaving it unchanged, based on its assigned value. If you start at zero, a queen takes the count to -1; a 4 on the next deal brings it back to 0 (-1 plus 1 = 0). A higher running count suggests that more high-value cards may remain in the deck.
3. Work Out the True Count
Casinos often deal blackjack using several decks. That makes counting more challenging, but doesn’t make it useless. In a multi-deck game, adjust the running count to a true count, also called a count per deck, to account for the cards still in play.
Divide the running count by your estimate of the decks remaining to get the true count. For example, a running count of 10 with 5 decks left gives a true count of 2 (10 ÷ 5).
4. Adjust Bets Based on the True Count
The true count can move up or down as the shoe progresses, and some counters adjust their wagers in response. They may bet more when the count rises and keep wagers small when it’s neutral or negative. Any betting choice should also take the player’s bankroll into account.
Does Card Counting Really Work?
Beginners often wonder whether card counting works. It depends on the game and the player’s skill: a skilled counter can gain a small edge over the casino, but not a large one. Experienced counters may secure an advantage of about 0.5% to 1%.
At online casinos, card counting is generally less useful than at a table, including a live-dealer game. Online live casinos may make tracking difficult by dealing from 8 decks, shuffling automatically or burning cards at the start of a shoe. These measures can make an accurate count difficult or even impossible.
Consequences of Card Counting
Card counting is not yet illegal, but a casino may ban a player it suspects of counting. Casinos can also change table conditions: they may alter the minimum or maximum bet, place the cut card earlier or introduce automatic shuffling machines. These measures make counting less useful and less enjoyable at the table. Rules and consequences vary by jurisdiction and venue.
Getting Started with Card Counting
Card counting takes consistent practice and patience to learn. It doesn’t call for exceptional intelligence, but you’ll need to think quickly and do mental arithmetic. With practice, counting may also help you become more familiar with blackjack decisions.
