The Hi-Lo System

The Hi-Lo is one of the most commonly used card counting systems devised for the game of blackjack. Most professional blackjack players and gambling experts use the Hi-Lo as an example when explaining how card counting actually works and there is a very good reason for this.

Players who count cards with the Hi-Lo system achieve a perfect balance between efficiency, accuracy, and ease of use. This renders it a great choice for aspiring counters especially those who prefer to play shoe games with multiple decks of cards.

The Hi-Lo system was devised by a man called Harvey Dubner as early as 1963. The system quickly attracted the attention of computer programmer Julian Braun who refined it. The refined version made its way to the pages of the second edition of Edward Thorp’s bestseller Beat the Dealer. The book was reprinted in 1966 which makes the Hi-Lo one of the oldest card counting systems in the blackjack universe.

The Mechanics of the Hi-Lo System

The Mechanics of the Hi-Lo SystemWe would like to say a few words about how card counting works before we proceed to explain the mechanics of the Hi-Lo system. Card counters keep track of the ratio of low to high cards that remain to be dealt. This knowledge enables competent players to vary their bet size in proportion to their advantage.

When the deck is rich in high cards, the chances of receiving a blackjack with extra payouts are higher. As the deck is depleted from high cards, the edge of the player significantly drops and the odds shift in favor of the house. Different card denominations have a different impact on the odds. To account for this fact, the Hi-Lo system assigns the following count values to the cards:

  • Aces, 10s, Queens, Kings, and Jacks are counted as -1 because they favor the player
  • Small cards 2, 3, 4, 5, and 6 are counted as +1 because they favor the house
  • The 7s, 8s, and 9s are considered neutral cards and have a value of 0

It follows that twenty cards have a value of +1 and twenty cards have a value of -1, which renders the Hi-Lo a balanced card counting system. Thus, if you take a standard full deck and count it down accurately, the result will always be zero. The same goes for all balanced counting systems. Adding and subtracting the value of each card as it appears on the layout gives you your running count but more on this a little later.

Blackjack Hi-Lo Card Counting Video Guide


Running Count to True Count Conversion

card countingLike all other balanced systems, the Hi-Lo requires players to convert their running count (RC) into what is known as the true count (TC). This conversion would not be necessary if one plays against a single deck of cards as the running count gives you an accurate enough idea of how favorable the remaining cards are.

Unfortunately, the poor conditions at the single-deck tables render these games unbeatable which is why most competent players prefer shoe games played with multiple decks, typically six or eight. The higher number of cards when multiple decks are in play dilutes the effect of removal of the cards, though.

For example, suppose you are dealt an Ace out of a single deck with 52 cards. The removal of the card has a more pronounced impact on the odds because you will have only three more Aces that can potentially give you blackjacks. But if you are playing an eight-deck game with a total of 416 cards and pull out one Ace, you are left with 31 more Aces to make blackjacks with. Respectively, the impact of the first Ace’s removal on the odds is not as significant.

Adjusting the Size of Your Bets with the Hi-Lo System

blackjack card countingSome people who read this article will undoubtedly ask themselves the question “When a blackjack shoe gets rich in high cards, doesn’t the dealer also have good chances of pulling out Aces and face cards?”. And they are right, some of the high cards will undoubtedly end up on the other side of the table.

But unlike the dealer, the card counter can split pairs, double down, and buy insurance. Additionally, the card counter has the option to decide whether to hit or stand on hard totals 12 through 16 whereas the dealer makes no playing decisions whatsoever and their play is always governed by the fixed rules of the house.

Despite this, the player will still lose more hands than they win even when card counting. The main advantage of the card counter results from sizing their bets depending on the advantage the remaining cards yield. To achieve this, one must first decide on a bet spread and range their bets in accordance with the count.

Some players prefer to use more conservative bet spreads for the purpose of reducing heat on behalf of the casino personnel. The members of the pit crew are well aware this game is beatable through counting and there is a good chance you might attract their attention if you opt for a more aggressive bet spread. If your level of play makes them uncomfortable, they will take counter-measures like reshuffling after every round or flat betting you. In the worst-case scenario, they might even prohibit you from playing blackjack or back you off altogether.

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Dan Helen

In the case of using the Hi-Lo blackjack card counting system, is it advised to stray away from the basic strategy?

Asked by: Helen | Asked on: 2023-06-17
Answered by: Dan | Answered on: 2023-06-18

While blackjack players are advised to always stick to basic strategy to ensure they are playing with the optimal RTP, this is not always the case for card counters. In some cases, depending on the true count that Hi-Lo card counters have come to, it may be better to adjust their moves based on the cards they know are left in the deck rather than following the basic strategy. Of course, deviating from basic strategy is recommended only to expert card counters who know how to make more favorable decisions, such as taking insurance or splitting pairs. If you believe that the true count suggests making a decision that goes against the basic strategy, you can take the risk of deviating from what is suggested to do. However, keep in mind that this type of decision is best to be done by experienced players who know the game by heart and understand the technique of card counting.