KO (Knock-Out) is an unbalanced, level-one, ace-reckoned card-counting system. Its initial running count and betting points depend on the number of decks and the exact KO variant; a universal zero start or +2 trigger is incorrect.
Origins and purpose
Olaf Vancura and Ken Fuchs published Knock-Out Blackjack in 1996. KO was designed to use an unbalanced running count without requiring the ordinary balanced-count true-count conversion in its published form.
That does not make every true-counted variation “more accurate,” nor does it make the original running-count method inferior. Comparisons must specify the complete strategy, indices, betting ramp, rules and penetration. QFIT simulations have found KO and Hi-Lo broadly comparable under matched SCORE assumptions.
KO card tags
The standard KO tags are:
- Cards 2 through 7: +1
- Cards 8 and 9: 0
- 10, J, Q, K and A: -1
Because the tags sum to +4 per deck rather than zero, the count rises as a complete pack is dealt. That designed imbalance is why the initial running count (IRC) changes with deck count.
Initial running count
A commonly documented KO-compatible schedule starts at 0 for one deck, -4 for two decks, -12 for four decks, -20 for six decks and -28 for eight decks. Use the IRC and indices published for the exact KO version you are learning; shifting the IRC requires corresponding shifts to its key counts, pivot and betting schedule.
The running count therefore does not universally begin at zero. A count value also cannot be interpreted without knowing the starting count, number of decks, penetration and strategy version.
Betting ramps are game-specific
Do not simply raise every wager at +2 or lower every wager below +2. Published and simulated ramps differ between single-, double-, six- and eight-deck games and depend on the rules, penetration, bankroll, maximum bet and acceptable risk of ruin.
Bet sizing is not merely “money management.” In an advantage game it should connect the estimated edge to bankroll risk, while respecting table limits and a tested maximum spread. No ramp guarantees a winning session.
Strategy deviations
KO books and software provide variant-specific index decisions. Apply only the indices that match the IRC convention, deck count and rules you trained. Basic strategy remains the starting point for decisions that have no applicable deviation.
Frequently asked questions
Is KO a true-count system?
The original published KO approach is an unbalanced running-count system. True-counted KO variants exist, but they require their own conversion, indices and validation.
Does KO always start at zero?
No. The IRC changes with deck count and convention; a common schedule is 0, -4, -12, -20 and -28 for 1, 2, 4, 6 and 8 decks.
Is +2 always the point to increase bets?
No. Use a game- and variant-specific ramp derived from published guidance or simulation and sized for your bankroll risk.
Does KO guarantee an advantage?
No. Suitable rules and penetration, accurate execution and an appropriate spread are still required, and variance can dominate finite results.
Further reading
Blackjack involves financial risk. Set affordable limits before playing, and see the responsible-gambling policy if play stops being recreational.
