The Hi-Lo card counting system
Hi-Lo is the most widely used blackjack count: simple enough to keep at casino speed, strong enough for serious play. This page covers the card values, the running and true count, how to size your bets, and the index plays that matter most.
card valuesrunning counttrue countbettingindex playsstrength
1Hi-Lo card values
Every card gets a tag of +1, 0 or −1. Low cards that leave the shoe are good for the player, high cards are bad:
| Card | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10–K | A |
|---|---|---|---|---|---|---|---|---|---|---|
| Hi-Lo | +1 | +1 | +1 | +1 | +1 | 0 | 0 | 0 | −1 | −1 |
Hi-Lo is a level 1 count (tags are only ±1) and it is balanced: one deck holds twenty +1 cards and twenty −1 cards, so a complete shoe always counts back to 0. The system was introduced by Harvey Dubner in 1963 and popularised by Stanford Wong’s Professional Blackjack.
2Keeping the running count
Start at 0 after every shuffle and add the tag of each card you see, including other players’ cards and the dealer’s hole card when it is turned over.
Round 2: 2 4 | 8 A | dealer 5 → +1 +1 0 −1 +1 = +2, running count +3
- Count in pairs: a 10 and a 5 cancel out, so skip them and only add what is left.
- Learn to recognise common groups at a glance (two tens and a small card = −1).
- Practise until you can count a full deck in under 25 seconds without mistakes: that is the Speed Count drill.
3Converting to the true count
In a multi-deck game the running count must be divided by the number of decks still to be played:
Running count +9, about 3 decks left → true count +3
Estimate the decks left from the discard tray to the nearest half deck and round the result down (floor). Most published Hi-Lo indices assume floored true counts. A step-by-step explanation with a calculator is in the beginner’s guide.
4Betting with Hi-Lo
Each +1 of true count adds roughly 0.5% to the player’s edge. A typical 6-deck game starts at about −0.5%, so the edge turns positive around TC +1 to +2. Raise your bet only from there:
| True count | Bet (units) |
|---|---|
| +1 or less | 1 |
| +2 | 2 |
| +3 | 4 |
| +4 | 6 |
| +5 or more | 8 |
A wider spread earns more but is easier for the casino to spot. Your unit should be small relative to your bankroll: the short-term swings of counting are large.
5Index plays: Illustrious 18 and Fab 4
Basic strategy assumes a neutral shoe. When the true count reaches a play’s index, the best play changes. Two short lists from Don Schlesinger’s Blackjack Attack capture most of the value. Indices below are for multi-deck games, dealer stands on soft 17, double after split allowed.
Illustrious 18
The single most valuable deviation is insurance: take it at true count +3 or higher. The hand plays:
| Hand | Index | Play | Otherwise |
|---|---|---|---|
| Hard 16 vs 10 | 0 | Stand at TC ≥ 0 | Hit below |
| Hard 15 vs 10 | +4 | Stand at TC ≥ +4 | Hit below |
| 10,10 vs 5 | +5 | Split at TC ≥ +5 | Stand below |
| 10,10 vs 6 | +4 | Split at TC ≥ +4 | Stand below |
| Hard 10 vs 10 | +4 | Double at TC ≥ +4 | Hit below |
| Hard 12 vs 3 | +2 | Stand at TC ≥ +2 | Hit below |
| Hard 12 vs 2 | +3 | Stand at TC ≥ +3 | Hit below |
| Hard 11 vs A | +1 | Double at TC ≥ +1 | Hit below |
| Hard 9 vs 2 | +1 | Double at TC ≥ +1 | Hit below |
| Hard 10 vs A | +4 | Double at TC ≥ +4 | Hit below |
| Hard 9 vs 7 | +3 | Double at TC ≥ +3 | Hit below |
| Hard 16 vs 9 | +5 | Stand at TC ≥ +5 | Hit below |
| Hard 13 vs 2 | −1 | Stand at TC ≥ −1 | Hit below |
| Hard 12 vs 4 | 0 | Stand at TC ≥ 0 | Hit below |
| Hard 12 vs 5 | −2 | Stand at TC ≥ −2 | Hit below |
| Hard 12 vs 6 | −1 | Stand at TC ≥ −1 | Hit below |
| Hard 13 vs 3 | −2 | Stand at TC ≥ −2 | Hit below |
Fab 4 surrenders
Where late surrender is offered:
| Hand | Index | Play | Otherwise |
|---|---|---|---|
| Hard 14 vs 10 | +3 | Surrender at TC ≥ +3 | Hit below |
| Hard 15 vs 10 | 0 | Surrender at TC ≥ 0 | Hit below |
| Hard 15 vs 9 | +2 | Surrender at TC ≥ +2 | Hit below |
| Hard 15 vs A | +1 | Surrender at TC ≥ +1 | Hit below |
The trainer’s Deviations mode quizzes all of these with a random true count around each index.
6How strong is Hi-Lo?
Counting systems are compared on three measures: betting correlation (how well the count predicts your edge, used to size bets), playing efficiency (how well it guides strategy changes) and insurance correlation. Hi-Lo scores about 0.97 / 0.51 / 0.76. That is very strong for betting and adequate for playing. Level 2 counts gain a little playing efficiency at the cost of much harder counting. See the full comparison of counting systems.
For educational purposes only. Edges and indices are approximate and depend on the exact rules.