The Hi-Lo Card Counting System In Blackjack

Note: This page assumes you understand basic blackjack strategy and have read our Card Counting overview. The Hi-Lo system is the most widely used card counting method and the best starting point for anyone learning to count. It offers an excellent balance of power, accuracy, and manageable complexity.

The Hi-Lo system was developed by Harvey Dubner in 1963 and further popularized by Edward Thorp, Stanford Wong, and many others since. It is a balanced, single-level counting system — meaning it assigns values of -1, 0, or +1 to every card, and a complete deck counted from top to bottom produces a sum of zero. This is the system that several of our experts use here at LegalOnlineBlackjack.com. This simplicity makes it the standard recommendation for new counters. For the historical background on Hi-Lo and other counting systems, Wikipedia's card counting article covers the development in detail.

The Hi-Lo Card Values

Card	Hi-Lo Value
2	+1
3	+1
4	+1
5	+1
6	+1
7	0
8	0
9	0
10	-1
Jack	-1
Queen	-1
King	-1
Ace	-1

The logic behind these assignments:

Low cards (2–6) are counted as +1 because when they leave the deck, the remaining shoe becomes relatively richer in high cards — which favors the player. Counting them as +1 tracks their removal.
Neutral cards (7–9) are counted as 0 because their impact on the player/dealer balance is minimal. Tracking them adds complexity without meaningful benefit.
High cards (10–Ace) are counted as -1 because their removal from the deck makes conditions less favorable for the player. A negative count reflects a deck that has been depleted of high cards.

Step 1: Master Individual Card Recognition

Before you can count a live blackjack game, you need to recognize the Hi-Lo value of every card instantly — no hesitation, no thinking. Here is how to build that recognition:

Take a standard deck of cards and flip through it one card at a time.
For each card, say the Hi-Lo value out loud: "+1" for 2–6, "zero" for 7–9, "-1" for 10–Ace.
Do this until there is no mental lag between seeing a card and knowing its value. This usually takes two to three focused sessions of 20–30 minutes each.

The goal is for the value assignment to feel as automatic as knowing that 2 + 2 = 4. No deliberation — just instant recognition.

Step 2: Count a Whole Deck

Once you can recognize individual values instantly, practice running the count through an entire deck:

Shuffle a deck and flip cards one at a time.
Maintain a running mental total, adjusting by each card's Hi-Lo value.
A complete balanced deck should end at exactly 0. If you do not land on 0, you made an error somewhere — start over.
Time yourself. Your target is to count through a complete 52-card deck in under 30 seconds with 100% accuracy before moving to game conditions.

Most beginners take one to two weeks of daily practice to reach the 30-second target. Some get there faster. Do not rush to the casino before you hit this benchmark — errors in a live game are costly.

Step 3: Count Pairs of Cards

In a real blackjack game, you do not see cards one at a time — you see them in groups. A key efficiency technique is to cancel pairs of opposite-value cards mentally before counting them:

A 5 (+1) and a King (-1) seen together = 0 net change. Cancel them without updating your count.
Two 3s seen together (+1, +1) = +2. Count them as +2.
A Jack (-1) and a 4 (+1) = 0. Cancel.

Practice this by flipping cards in pairs rather than one at a time. This builds the speed needed for a real game where multiple cards appear on the table simultaneously.

The Running Count in Practice

The running count is your cumulative total of all Hi-Lo values seen since the last shuffle. Here is an example of tracking the count through a few hands:

Cards Seen	Hi-Lo Values	Running Count Update	Running Count
Start of shoe	—	—	0
Player: 8, 5	0, +1	+1	+1
Dealer up card: 4	+1	+1	+2
Player hits: King	-1	-1	+1
Dealer hole: 7	0	0	+1
Dealer hits: 6	+1	+1	+2
Dealer hits: 10	-1	-1	+1

After these hands, the running count is +1 — slightly positive, modestly favorable for the player.

Step 4: Convert to True Count

The running count tells you how many more low cards than high cards (or vice versa) have been removed from the shoe. But its significance depends on how many decks remain. A running count of +6 with one deck remaining is a very favorable situation. The same +6 with four decks remaining is much more modest.

The true count normalizes for remaining decks:

True Count = Running Count ÷ Estimated Decks Remaining

Estimating decks remaining takes practice. Watch the discard tray — as it fills, you can estimate how many decks have been used and subtract from the total shoe size to get decks remaining. After some practice, this becomes an unconscious estimate you do naturally.

All betting decisions and strategy deviations are based on the true count. See our True Count guide for a complete breakdown.

Step 5: Bet Spreading Based on the True Count

Here is a basic bet spreading guideline for a beginning Hi-Lo counter in a 6-deck game:

True Count	Bet Size (as multiple of minimum)	Notes
0 or below	1x (minimum)	No player edge; minimize exposure
+1	2x	Slight advantage emerging
+2	4x	Meaningful advantage
+3	6x	Strong advantage; take insurance
+4 or above	8x to max	Maximum advantage; bet aggressively

At a $10 minimum table with a 1-to-8 spread, this translates to $10 minimum bets at neutral or negative counts and up to $80 at highly favorable counts. See our Betting Spreads guide for more detail on spreads and risk.

Step 6: Apply Strategy Deviations

Beyond bet spreading, the true count triggers changes to some basic strategy decisions. The most important for Hi-Lo counters are covered in our Strategy Deviations page. The top priority deviation is insurance at true count +3 or higher.

Practice Routine for Building Hi-Lo Proficiency

A structured practice approach produces faster results than casual counting:

Week 1–2: Card value recognition drills. Count individual cards until instant, then count a full deck targeting under 30 seconds.
Week 3–4: Count pairs. Practice canceling opposite-value pairs without updating the running count.
Week 5–6: Simulate a game. Deal cards to yourself and a simulated dealer, count every card dealt, and maintain the running count while simultaneously making basic strategy decisions.
Week 7–8: Add true count conversion. Practice estimating remaining decks and converting running count to true count on the fly.
Week 9+: Add distractions — TV, music, conversation. Casino environments are deliberately designed to break concentration.

Hi-Lo Efficiency Metrics

The Hi-Lo system is evaluated on two key metrics:

Metric	Hi-Lo Score	What It Means
Betting Correlation (BC)	0.97	How well the count predicts when to increase bets. Excellent.
Playing Efficiency (PE)	0.51	How well the count indicates strategy deviations. Moderate.

The high betting correlation is why Hi-Lo remains the most recommended system for most counters — bet sizing is responsible for the majority of a counter's edge, and Hi-Lo excels at it. The moderate playing efficiency means more complex systems (like Omega II or Wong Halves) identify strategy deviations more precisely, but the added complexity is rarely worth it for most players. See our Other Counting Systems guide for comparisons.

Common Hi-Lo Mistakes

Losing the count when distracted. A conversation, a wrong turn of a card, or a brief lapse can throw off the count. Practice in distracting environments before going live.
Miscounting face-up games with multiple players. All visible cards — including other players' hands — must be counted. Do not only count your own cards.
Forgetting to count the dealer's hole card when revealed. The hole card counts too. Every card dealt is part of the count.
Changing bets too abruptly. Sudden large bet jumps attract attention. Practice smooth, gradual bet variation.