Card counting systems compared
Hi-Lo, KO, Omega II, Zen and Wong Halves side by side: what each card is worth, how hard each count is, and how much it gains. All five can be practised in the trainer.
card valuescomparisontermssystemswhich one?
1Card values by system
| System | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10–K | A |
|---|---|---|---|---|---|---|---|---|---|---|
| Hi-Lo | +1 | +1 | +1 | +1 | +1 | 0 | 0 | 0 | −1 | −1 |
| KO (Knock-Out) | +1 | +1 | +1 | +1 | +1 | +1 | 0 | 0 | −1 | −1 |
| Omega II | +1 | +1 | +2 | +2 | +2 | +1 | 0 | −1 | −2 | 0 |
| Zen Count | +1 | +1 | +2 | +2 | +2 | +1 | 0 | 0 | −2 | −1 |
| Wong Halves | +0.5 | +1 | +1 | +1.5 | +1 | +0.5 | 0 | −0.5 | −1 | −1 |
2Level, balance and efficiency
| System | Level | Type | True count? | Starting count | BC | PE | IC |
|---|---|---|---|---|---|---|---|
| Hi-Lo | 1 | Balanced | Yes | 0 | 0.97 | 0.51 | 0.76 |
| KO (Knock-Out) | 1 | Unbalanced | No | 0 (1 deck) · −20 (6 decks) | 0.98 | 0.55 | 0.78 |
| Omega II | 2 | Balanced | Yes | 0 | 0.92 | 0.67 | 0.85 |
| Zen Count | 2 | Balanced | Yes | 0 | 0.96 | 0.63 | 0.85 |
| Wong Halves | 3 | Balanced | Yes | 0 | 0.99 | 0.56 | 0.72 |
BC = betting correlation, PE = playing efficiency, IC = insurance correlation, as commonly quoted in the blackjack literature. Higher is better.
3What the terms mean
- Level: the largest tag a card can have. Level 1 counts only use ±1 and are the easiest to keep fast and accurately. Level 2 and 3 counts are more precise but harder.
- Balanced: a full shoe counts back to 0, and you divide the running count by the decks left to get a true count.
- Unbalanced: a full shoe does not sum to 0. You start from a negative initial count and use the running count directly, with no division.
- Betting correlation matters most for your bet sizing, which is where most of a counter’s profit comes from. Playing efficiency matters for strategy deviations.
4The systems
Hi-Lo
Level 1, balanced. The standard count, with the largest body of published index plays. Strong betting correlation and the easiest balanced count to learn. Full details on the Hi-Lo page.
KO (Knock-Out)
Level 1, unbalanced. Same as Hi-Lo except that 7s count +1. Each deck therefore adds +4, so the count starts at 4 − 4 × decks (−20 for six decks) and a full shoe ends at +4. No true count conversion is needed, which makes it the easiest count to use at the table. From Olaf Vancura and Ken Fuchs’s Knock-Out Blackjack.
Omega II
Level 2, balanced. Fours, fives and sixes are +2, tens −2, and aces count 0. Players usually keep a separate ace side count for betting. High playing efficiency, but demanding to keep accurate. Popularised by Bryce Carlson’s Blackjack for Blood.
Zen Count
Level 2, balanced. Like Omega II but aces are −1 and 9s are neutral, so no side count is needed. A good balance of betting and playing strength. From Arnold Snyder’s Blackbelt in Blackjack.
Wong Halves
Level 3, balanced, with half-point tags (the 5 is worth +1.5). It has the highest betting correlation of the five but is the hardest to keep. Many players double every tag to count in whole numbers. From Stanford Wong.
5Which system should you learn?
- Start with Hi-Lo. Most books, index tables and training material use it, and the extra gain of harder counts is small compared to the cost of counting errors.
- Choose KO if the true count conversion is what slows you down.
- Move to Zen or Omega II only once Hi-Lo is completely automatic and you play mostly single- or double-deck games, where playing efficiency matters more.
Whatever the system, accuracy at speed matters more than the system’s efficiency. Train the running count until it is automatic.
For educational purposes only.