When Should We Count Cards?

A version of this article appears in TWISTED LOGIC: Puzzles, Paradoxes, and Big Questions. By Leighton Vaughan Williams, Chapman & Hall/CRC Press. 2024.

Card Counting: A Winning Strategy in Blackjack

In 1962, Ed Thorp introduced a strategy that would forever change the landscape of blackjack: card counting. His book, Beat the Dealer: A Winning Strategy for the Game of Twenty-One, presented a system based on probability theory that allowed players to gain an advantage over the house. Since then, card counting has become a topic of fascination for blackjack players worldwide.

Understanding the Basics of Blackjack

To grasp the significance of card counting, it’s essential to understand the fundamentals of blackjack. The basic objective of the game is simple: players aim to draw cards that beat the dealer’s hand without exceeding a total of 21. While basic strategy provides players with a foundation for optimal gameplay, card counting takes it a step further by incorporating the knowledge of which cards have already been dealt.

The Concept of Card Counting

Card counting revolves around the concept that certain cards have a different impact on the game’s outcome than others. By using a system to estimate the ratio of high and low cards still in the deck, the technique allows players to adjust their betting and playing decisions based on the remaining composition of the deck.

Popular Card Counting Systems

Several card counting systems have been developed over the years, each with its own approach to assigning values to the cards. Here are a few notable examples:

1.       Hi-Lo Count: The Hi-Lo Count is one of the simplest and most popular card counting systems. It assigns a tag of +1 to low cards (2–6), a tag of 0 to neutral cards (7–9), and a tag of −1 to high cards (10-Ace). By maintaining a running count based on these tags, players can assess the overall composition of the remaining deck.

2.       KO Count: The Knock-Out (KO) Count is another popular system. In this method, all 7s, 8s, and 9s are assigned a tag of +1, while 10s through Aces are assigned a tag of −1. The remaining cards are considered neutral (tag 0).

3.       Hi-Opt Systems: Hi-Opt systems, such as the Hi-Opt I and Hi-Opt II, aim to provide a more accurate assessment of the deck’s composition by considering more card values.

4.       Zen Count: The Zen Count system is known for its precision in tracking the deck’s composition. It assigns a variety of values to different cards, creating a more detailed count. This system, while more complex than the other systems, can offer a greater edge to skilled players.

Additional Considerations: It’s crucial to understand that these systems vary in complexity and suitability for different players. Advanced systems like the Zen Count may offer more accuracy, but they require more practice and skill. Additionally, systems may require converting the ‘running count’ into a ‘true count’ by accounting for the number of decks remaining in the shoe. This adjustment helps in accurately determining the player’s edge.

Making Informed Decisions

By monitoring the running count and employing the chosen card counting system, players can make in-running staking decisions. When the count indicates an abundance of high cards in the remaining deck or decks, this is generally good for the player, bad for the house. In this case, players may choose to increase the size of their bets. Conversely, when the count indicates a higher proportion of low cards remaining in the deck, players may opt for smaller bets and more conservative gameplay.

Challenges and Countermeasures

Casinos are well aware of card counting strategies and have implemented various countermeasures to detect and deter such activities. They employ techniques such as automatic shuffling machines, frequent deck changes, and trained personnel to identify suspected card counters. Consequently, players who employ card counting techniques also employ camouflage methods to avoid detection. This involves blending in with other players, varying bet sizes, acting like a casual player, and avoiding suspicious behaviour.

The Evolution of Card Counting

Over the years, card counting has evolved alongside advancements in technology and changes in casino practices. The rise of online blackjack games and continuous shuffling machines (CSMs) has posed new challenges for card counters. Online casinos employ random number generators (RNGs), making it impossible to track specific cards. CSMs continuously shuffle the cards, eliminating any opportunity to gain an advantage through card counting.

Conclusion: Beating the Odds

Card counting revolutionised the game of blackjack by providing players with a mathematical strategy to gain an edge over the house. However, it requires skill and practice to implement while evading detection. Still, card counting remains a challenging yet fascinating aspect of blackjack gameplay, and players can in principle adapt their techniques to the countermeasures employed by casinos. It continues to captivate players who seek to test their skills and beat the odds at the blackjack table.