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KO (Knock-Out) Card Counting System

KO (Knock-Out) is Hi-Lo with one change: the 7 counts +1. That makes the count unbalanced by +4 per deck, and in exchange you never convert to a true count. You start the running count at 4 - 4 × decks and make decisions from the running count alone.

Level
1
Balanced
No (+4/deck)
True count
No
Difficulty
Easy

KO Card Values

Cards Tag Per deck
2-7 +1 24 cards
8-9 0 8 cards
10-A -1 20 cards

"10" means every ten-value card: 10, J, Q and K. A full deck adds up to +4, which is what makes the count unbalanced.

How to Count KO

  1. Set the starting count. Before the first card, start the running count at 4 - 4 × decks. Counted from there, a full shoe always ends at +4, whatever the number of decks.
  2. Keep a running count. Add each card's tag as it is dealt. Count in pairs where you can: a card tagged +1 and a card tagged -1 cancel to 0.
  3. Bet off the running count. No division needed. Compare the running count to the key count and pivot below.
Decks Starting count Key count Pivot
1 0 +2 +4
2 -4 +1 +4
6 -20 -4 +4
8 -28 -6 +4

The key count is where you start raising your bet. The pivot is the running count that means the same thing at every shoe size: about +4 per remaining deck. Away from the pivot, the running count is an approximation of your edge, which is the price of skipping the true count.

Published Efficiency

Measure KO Hi-Lo
Betting correlation 0.98 0.97
Playing efficiency 0.55 0.51
Insurance correlation 0.78 0.76

Widely published values from standard comparison tables, such as those by Arnold Snyder, Stanford Wong and the Wizard of Odds, not results from our own simulations. See the full comparison.

Pros and Cons

Pros

  • No division at the table. Betting decisions come straight from the running count.
  • Nearly the same tags as Hi-Lo, so switching between the two later is easy.
  • Published correlations on par with Hi-Lo (0.98 betting, 0.55 playing).
  • The pivot sits at +4 for every shoe size, so the key numbers are easy to remember.

Cons

  • The running count maps exactly to your edge only at the pivot; away from it, it is an approximation, so KO is slightly less precise than Hi-Lo with a full true count.
  • You must set the starting count correctly for the number of decks before the first card.
  • Fewer published index plays than Hi-Lo.

Who KO Suits

Beginners and recreational players who want a real edge without mental division, and anyone whose Hi-Lo accuracy breaks down at the true count step.

Usually credited to Olaf Vancura and Ken Fuchs, Knock-Out Blackjack.

Practice KO

Count a real shoe with KO tags, starting from the KO initial count, at the dealing speed you choose.

Start the KO Drill

Frequently Asked Questions

What is the KO initial running count?

Start at 4 - 4 × decks: 0 for a single deck, -4 for two decks, -20 for six decks and -28 for eight decks. Counting a full shoe from there ends at +4, because each deck adds +4 to the count.

What are the KO key count and pivot?

With the standard starting count, the key count, where you begin raising your bet, is +2 for one deck, +1 for two decks, -4 for six decks and -6 for eight decks. The pivot is +4 at every shoe size: a running count of +4 always means about +4 per remaining deck.

Why is KO called unbalanced?

A deck has twenty-four +1 cards (2 through 7) and only twenty -1 cards (tens and aces), so a full deck sums to +4 instead of 0. The negative starting count absorbs that drift, which is what lets the running count stand in for the true count.

Is KO easier than Hi-Lo?

Yes. The tags are almost identical and the true count step disappears, which is why we rate KO as Easy and Hi-Lo as Moderate. The trade-off is a small loss of precision and fewer published index plays.