How to Count Cards with Hi-Lo
Why counting works
A deck full of small cards helps the dealer. A deck full of tens and aces helps you, because you get more blackjacks paid at 3:2, doubles win more, and the dealer busts more often. Card counting is a way to track whether the remaining cards favor you, so you can bet more when they do and less when they do not.
It does not predict the next card. It tracks the balance of what is left.
Hi-Lo card values
Hi-Lo is the most common counting system because it is easy. Every card gets one of three values:
| Cards | Count value |
|---|---|
| 2, 3, 4, 5, 6 | +1 |
| 7, 8, 9 | 0 |
| 10, J, Q, K, A | -1 |
When low cards leave, the cards left are richer in tens and aces, which is good for you, so low cards add to the count. When high cards leave, the cards left get worse for you, so high cards subtract.
The running count
Start at zero when the shoe is shuffled. As each card is revealed, add its value to your total. If the first five cards are 5, K, 3, 8, 2, the count goes +1, 0, +1, +1, +2. That total is the running count. You keep the whole table in your head, including the dealer's cards and the other players' hands.
A positive count means more high cards remain. A negative count means more low cards remain.
Converting to a true count
A running count of +4 means more with one deck left than with five. So you divide by the number of decks remaining to get the true count. This is the number you bet on. We cover it in true count conversion.
Betting with the count
This is where the count matters most. Counting does not change your play much. It changes your bet size. When the true count is low or negative, bet the minimum. When it climbs, raise your bet. A simple approach is to bet one unit at a count of +1 or lower and add a unit for each point above that.
You also change a few plays, such as taking insurance at a true count of +3 or higher. Those exceptions are called deviations. Learn basic strategy first, so it is automatic, before you try any of that.
Be realistic
Counting is hard to use well, and the rewards are modest.
- The edge is small. A good counter gains about 0.5% to 1.5% over the house, depending on the game and the bet spread.
- The variance is big. You can play perfectly and still lose for days. The edge shows up over thousands of hands.
- You need a bankroll. To survive the swings, you need many betting units set aside.
- Mistakes cost more than the edge. A counting error or a missed basic strategy play can wipe out your small advantage.
Counting is a skill that you can practice for free. It is not a way to earn a living for most people.
Is it legal?
Yes. Counting uses only your brain, and it is not cheating. However, casinos are private businesses and may ask a suspected counter to stop playing blackjack or to leave. Using a device to count is illegal in many places.
When counting does not work
- Continuous shuffling machines. The cards are reshuffled after every hand, so there is no count to track. See CSM.
- Shallow penetration. If the dealer cuts off a large part of the shoe, the count rarely gets high. See deck penetration.
- 6:5 games. The payout cost is too large to overcome.
How to practice
- Take a deck of cards and flip them one at a time. Add as you go. A full deck always ends at zero. If yours does not, find your mistake.
- Time yourself. Aim to go through a deck in under a minute, with a correct end count.
- Practice with pairs. Cancel +1 and -1 cards as you see them, so 6 and K cancel to zero.
- Add noise. Count while music or the TV is on.
- Use the count practice view in the trainer, and play hands while counting.
Common questions
Can I really win by counting?
You can gain a small edge in the right game. You will still have losing sessions, and a few players do it well.
Do I have to memorize the whole deck?
No. You only track one number, the running count, plus the decks left.
Is Hi-Lo the best system?
It is not the strongest, but it is the easiest to use without errors, which matters more.
Will I get thrown out?
You can be asked to leave. Casinos can refuse service. They cannot have you arrested for counting.