Hi-Lo and KO (Knock-Out) are the two counting systems beginners compare most. Both use simple +1 / 0 / −1 tags. The fork is what you do with the number after you have it: divide by decks remaining (Hi-Lo) or compare the running count to a key count (KO).
Count All Blackjack’s free trainer is built around Hi-Lo (RC and TC on the bar). Use it to learn conversion even if you later prefer KO’s running-count style.
System comparisons here are for study. They are not a promise of profit. Practice only — no real-money gambling.
Tags at a glance
Hi-Lo: 2–6 = +1, 7–9 = 0, 10–A = −1. A full deck counted cleanly returns to 0 (balanced).
KO: 2–7 = +1, 8–9 = 0, 10–A = −1. Sevens are +1 instead of 0, so a full deck does not return to 0 (unbalanced).
That one rank — the seven — is the whole mechanical difference in the tags. Everything else is about how you use the running count. Details live in the Hi-Lo guide and KO guide.
Balanced vs unbalanced
A balanced count (Hi-Lo) is designed so the tags on a complete deck sum to zero. To compare early-shoe and late-shoe counts, you convert to true count: RC ÷ decks remaining.
An unbalanced count (KO) is designed so you can skip that division. You start at an initial running count (IRC) that depends on the number of decks, then watch for published key counts (pivot, insurance, betting ramps) instead of a true count.
True count vs key count
- Hi-Lo — keep RC, estimate decks left, divide, then use TC for practice bet size and later index plays.
- KO — keep RC only. When it crosses a key count, that is your signal. No division at the table.
If mental division is the thing that breaks you at speed, KO is the simpler live process. If you want the same number the majority of books and trainers use, Hi-Lo is the simpler curriculum.
Who should use which
- Start with Hi-Lo if you are using this site’s trainer, most published charts, or you already understand true count.
- Start with KO if you have tried Hi-Lo and the TC step is the only thing you cannot keep at speed.
- Do not alternate weekly. Tags will collide (sevens especially). Pick one for a month of home practice.
When either system is automatic, the systems hub covers Hi-Opt, Omega II, and Wong Halves for players who want more playing efficiency or betting correlation — at the cost of harder tags.
Drill Hi-Lo on a live shoe
RC and TC on screen as an answer key. Practice only — virtual chips.
FAQ
Is KO easier than Hi-Lo?
KO is easier at the table if you want to skip dividing by decks remaining. Hi-Lo is easier to study because more trainers and charts use it.
Should I switch from Hi-Lo to KO?
Only if true-count conversion is what fails in your drills. Switching every few days will mix the sevens and slow you down.
Which is more accurate?
Both are level-1 counts. Hi-Lo’s true count is a clean way to talk about density per remaining deck. KO trades that conversion for a running-count process with key counts. For learning, consistency matters more than a small efficiency gap.
Next: Hi-Lo reference, KO reference, or play a shoe.