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Hi-Lo card counting system explained

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Why Hi-Lo?

Hi-Lo is the best-known counting system because it only uses three values: +1, 0 and −1. It is easy enough for a beginner to learn in an afternoon and strong enough that many serious players never switch.

Why these values work

Each tag reflects how much a card’s removal helps or hurts the player. Low cards (2–6) are good for the dealer: they let a stiff hand like 12 to 16 draw without busting. When they leave the shoe, the remaining cards favor you, so they earn +1. Tens and aces are good for you (blackjacks, doubles, and dealer busts), so when they leave, the remaining cards favor the dealer, which earns −1. The 7, 8 and 9 have little effect either way, so they count as 0.

The tag values

Cards Tag Why
2, 3, 4, 5, 6 +1 Low cards leaving the shoe help the player later
7, 8, 9 0 Neutral
10, J, Q, K, A −1 High cards leaving the shoe hurt the player later

In each suit there are five low cards (2–6) and five high cards (10, J, Q, K, A), so a full deck has 20 low cards (+20) and 20 high cards (−20). They sum to exactly zero.

Keeping the running count

Start at 0 when the cards are shuffled. For each card that you can see, add its tag. That includes your cards, the dealer’s up card, other players’ cards, and any hit cards. Never reset in the middle of a shoe.

Worked example. The first hand of a new shoe shows these cards in order:

tag +1
count 1
tag -1
count 0
tag +1
count 1
tag 0
count 1
tag -1
count 0
tag +1
count 1

The running count is +1 after six cards. Notice that you only ever remember one number, not the list of cards.

Counting faster: cancel in pairs

Experts rarely add one card at a time. They group cards, and the most useful trick is cancelling: a low card and a high card cancel each other out. A hand of 4 and Q is “0”. A hand of 6 and 5 is “+2”. A hand of K and A is “−2”. Practice by looking at a two-card hand and calling out its net value instead of each card’s value separately.

Try it

Work out the running count after each group of cards, starting from zero. Use the hints if you get stuck.

Try it: What is the running count after these cards?

1
0
−1
1
−1

Try it: What is the running count after these cards?

1
1
1
−1
1
0
1

Try it: What is the running count after these eight cards?

−1
−1
−1
0
1
−1
0
−1

A simple practice routine

Counting is a skill you build in short sessions, like a musical instrument:

  1. Learn the three groups until you can instantly say “plus, zero, minus” for any card.
  2. Count down a single deck of real cards, one at a time. A beginner takes a couple of minutes; a skilled counter does it in under 30 seconds. If you end on 0, you counted correctly.
  3. Count in pairs to speed up, as described above.
  4. Add distractions: music, conversation, a timer.
  5. Add playing decisions. Count while you also make basic-strategy decisions on real hands.

Common mistakes

  • Forgetting the dealer’s hole card. It’s counted when the dealer turns it over, even if the hand is already decided.
  • Counting cards you can’t see. If a player folds their cards face-down, don’t guess.
  • Losing the count after a conversation. Practice counting with the TV on or a friend talking.
  • Not resetting at the shuffle. A new shoe means a new count of 0.

Next steps

Hi-Lo’s running count only tells part of the story: what matters is how many cards are left. Next, learn how to convert it into a true count.