Is the Knockout “KO” Card Counting System Really Better Than the Rest?

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Ask any casual gambler about the best way to beat the house, and you’ll inevitably hear tales involving intrepid card counters.

From the famed MIT Blackjack Team — which was immortalized in the film 21 (2008) starring Kevin Spacey as a math professor turned count team leader — to the instructional material published by the legendary gambling author Stanford Wong, card counting has been embedded in the public consciousness for decades.

And at first glance, that makes perfect sense…

All it takes is a quick back-of-the-napkin lesson to get the gist of counting cards at the blackjack table.

When you see plenty of high cards hit the felt as the dealer does their thing, you know the odds of hitting high totals like 18, 19, 20, and 21 decrease accordingly. Thus, you should lower your bets to the table minimum.

Conversely, when your scans show a ton of low cards getting dealt, it’s time to ramp up the betting because your odds of hitting premium totals have now gone up.

After hearing this brief introduction, thousands of gamblers strike out to Sin City each and every year hoping to try their hand at the blackjack tables. Many even make a point to study card counting systems, of which literally hundreds have been devised over the last few decades.

It all began back in 1962 when math genius Edward O. Thorp invented the first effective method for counting cards and adjusting one’s blackjack plays accordingly. Thorp’s “Ten Count” counting system established the template, and from there, dozens of blackjack sharps and math whizzes have taken their own shot at creating the best way to count cards.

Most Popular Card Counting Systems

  • Ace 5
  • Hi Lo
  • Hi Opt I
  • Hi Opt II
  • Halves
  • Knockout KO
  • Omega II
  • Red 7
  • Speed Count
  • Ten Count
  • Zen

Each of these systems takes a particular path to the same destination — gaining insight into whether the deck is “optimal” or “suboptimal” going forward. When a proficient card counter can pin down which cards have been previously dealt, they can size their bets accordingly to take advantage — and even flip the house’s inherent 1% edge in their own favor — the minute a deck’s count creates a higher likelihood of landing the winning hand.

But which card counting strategy reigns supreme?

Well, that’s all a matter of subjective interpretation, of course, because all card counters are created differently.

Many folks who are blessed with supercomputer minds and mathematical acumen prefer balanced systems like the Omega II because they don’t mind running through complex calculations like long division and such on the fly.

Others out there who aren’t ready for such taxing mental math might take a liking to an unbalanced system like the Red 7, as it cuts the process down to simple addition and subtraction.

Of course, the more complex the system, the better it will perform on a statistical basis. On the other hand, those slight gains in the player advantage don’t really matter all that much if you’re unable to keep things sorted in your head during a hectic game of blackjack in the casino setting.

Earlier, we covered one of the more widely used card counting methods out there — the Golden Touch Speed Count invented by Henry Tamburin and Frank Scoblete. The Speed Count lives up to its name by making the process streamlined and efficient, but doubts remain concerning its overall effectiveness.

Today, it’s time to tackle another beloved member of the card counting family — the Knockout KO system.

Introduction to the Knockout KO Count System and Its Origins

The Knockout “KO” card counting system was created in 1998 when Olaf Vancura published “Knock-Out Blackjack: The Easiest Card-Counting System Ever Devised” (1998).

Having earned his Ph.D. in physics from the prestigious Johns Hopkins University in 1992, Vancura found himself studying the origins of the universe at the Harvard-Smithsonian Center for Astrophysics by day.

By night, however, the mathematically inclined Vancura liked to visit the casino and gamble on card games — especially blackjack. Eventually, he combined his love for cards with his academic bona fides, creating and teaching a course at Tufts University on the math behind gambling games. Convened as part of the Tufts Experimental College, Vancura’s course quickly wound up becoming one of the most popular on campus.

This acceptance from students and colleagues alike prompted Vancura to write a textbook entitled “Smart Casino Gambling: How to Win More and Lose Less,” which was published in 1996.

As he later told the American Physical Society (APS) during a retrospective interview, Vancura was primarily interested in dispelling the common myths and misconceptions surrounding concepts like card counting:

“I couldn’t find [a textbook] without junk.”


“I didn’t want to expose my students to the nonsense that existed in current tomes about card counting.”

Shortly after “Smart Casino Gambling” hit the university bookstore’s shelves, Vancura extended an invitation to the director of casino operations at Foxwoods — a Connecticut casino resort which ranks as one of the largest in all of America — asking him to speak to students.

This connection led Vancura into the wider world of the gaming industry, and he soon decided to leave astrophysics behind for a new career as a consultant tasked with creating new casino games for Mikohn Gaming.

After relocating to Las Vegas in 1997, Vancura eventually met up with Ken Fuchs, who worked with Motorola as a senior electrical engineer specializing in cryptographic encryption. Fuchs also had a gambling-oriented hobby, one which involved the development of computer simulations designed to study optimal blackjack strategy.

And just like that, a marriage made in gambling heaven was born.

One year later, the pair’s collaborations began focusing on perfecting the “unbalanced” count, a concept originally conceived by card counting icon Arnold Snyder in “Blackbelt in Blackjack” (1983). When using the “Red 7” count introduced by Snyder, players relied on the following values to develop their running count.

Card Rank Values in the Red 7 Count

  • Aces and 10s = -1
  • 2s, 3s, 4s, 5s, and 6s = +1
  • Red 7s = +1
  • Black 7s, all 8s, and all 9s = 0

With 20 cards in the deck valued at -1 but 22 cards worth +1, Snyder’s Red 7 count was deemed unbalanced as opposed to the “balanced” systems of old which divided the deck’s values into even proportions.

Red 7 Card Counting System

In the preface to “Knock-Out Blackjack,” Vancura and Fuchs trace the lineage of their Knockout KO count directly to Snyder and his innovative Red 7 system:

“The Red 7 system was a breakthrough in simplicity, a pseudo-Level 1 system with all cards valued at +1, 0, or -1.”


“Due to the unbalanced nature of the system, no true count conversion, hence mental multiplication and division, is ever necessary.”


“The Knockout system is predicated on many of the important principles introduced by Snyder.”

As they alluded to in their tribute to Snyder, the purpose of an unbalanced count like the Red 7 or Knockout KO is to remove the need to convert your “running” count into a “true” count.

When utilizing a balanced count, players must keep track of two different mathematical processes at the same time.

First, you need to track exposed cards and tabulate their values to determine your running count. Concurrently, the counter needs to maintain a separate count of all cards dealt to determine how many decks are left in the shoe. Finally, knowing their running count number, a balanced count practitioner divides it by the number of decks in play to arrive at the true count.

Like Snyder before them, Vancura and Fuchs sought to eliminate that tedious mental math by limiting the player’s focus to the running count only. This was accomplished by fusing the balanced count methodology with flexible starting count figures, which fluctuate depending on how many decks the shoe contains at the start.

Introductory Lesson on How the KO Count Works at the Table

Taking a look at the point values used in the Knockout KO system below, you should be able to spot a certain sense of familiarity.

Card Rank Values in the Knockout KO System

  • Aces and 10s = -1
  • 2s, 3s, 4s, 5s, 6s, and 7s = +1
  • 8s and 9s = 0

That’s right, other than the provision about valuing the red 7 of hearts and 7 of diamonds as +1 — and thus separate from their black 7 of spades and 7 of clubs cousins and their 0 value — the Knockout KO and Red 7 systems are essentially identical.

This similarity holds true when examining how the Knockout KO count manages to avoid those pesky true count conversions. Instead of assigning players with the task of counting the decks remaining and dividing their running count by that number, both the Red 7 and Knockout KO systems factor deck density into the starting count.

Here’s how it works.

When you’re using the Knockout KO approach at a single-deck table, you’ll go ahead and start with a 0 count like you would in the classic balanced systems.

But up the deck density to a two-deck shoe, and your starting count now shifts to -4. Make it a six-deck shoe, and the starting count drops even lower to -20, while an eight-deck shoe requires the count to start at -28.

Using these neutral and negative starting counts, players sift through the deck’s exposed cards and adjust their running count accordingly, hoping to see the count eventually climb to the low negatives and positives. As the count increases, the Knockout KO system uses a set of “Key Count” numbers to let you know exactly when to pivot and pump up the betting.

Using the table below, you can see the start counts — deemed initial running counts (IRCs) in advantage play vernacular — for various deck densities, alongside the key count needed to begin betting bigger.

Knockout KO Initial Running Counts (IRCs) and Key Counts

Decks IRC Key Count
1 0 +2
2 -4 +1
6 -20 -4
8 -28 -6

As you can see, more decks in the shoe means more positive progress needed in your running count to finally reach the key count.

A single-deck grinder only needs to see the count climb by +2 (from 0 to +2) in order to size their wagers higher. But if you’re sitting in a double-deck game, you’ll need to count +5 (from -4 to +1) before going for the gusto. Six-deck shoes have a whopping 312 cards to wade through, so players must count upward by +16 (from -20 to -4) before firing max bets. And finally, eight-deck tables can’t be pounded until you see a +22 push (from -28 to -6).

We can use an example hand to see how the Knockout KO count really works in action. Owing to the rarity of single- and double-deck blackjack in modern casinos, we’ll roll with the standard six-handed shoe found in most Sin City games. The table features yourself playing Hand 1, along with three other players trying to beat the dealer.

Hand 1 Hand 2 Hand 3 Hand 4 Dealer Hand
8d / 3h As / Jh 5h / 4d 2c / 10c 5c / 5h

Because we’re using a six-deck shoe, the initial running count (IRC) begins at -20.

Most counters try to separate cards into “sides,” rather than doing a straight up and down count, so we’ll start with the low-ranked cards (2, 3, 4, 5, 6, 7) valued at +1. You see six of these low cards on the table, good for +6, so your start count moves from -20 to -14.

Next, we’ll do the high cards (A, K, Q, J, 10) worth -1, and with three of them out there for -3, the count drops from -14 back to -17.

The next step in the hand is players acting on the cards, followed by the dealer, so we’ll run through one more count before this deal is done.

Hand 1 Hand 2 Hand 3 Hand 4 Dealer Hand
8d / 3h As / Jh 5h / 4d 2c / 10c 5c / 5h
Double (Kd) BJ Hit (6s) / Hit (7c) Hit (2s) / Hit (9c) (4d) / Hit (5c)
21 21 22 (Bust) 23 Bust 19

You play the 11 perfectly with a well-timed double-down plus a face card for a 21, but while that’s a nice treat, the name of the game here is counting cards.

Our count stands at -17, so we’ll start with the low card side and see where we get. Five of the baby cards equals +5, so we’re up to -12 for the moment. After subtracting -1 for the single high card to come out, the count slides back to -13.

Moving from the -20 start count to -13 represents significant progress, so if things keep up on this track, we’ll hit the key count of -4 before long.

When you do cross over the key count, try to utilize a progressive wagering scale to take advantage of increasingly favorable deck conditions.

In other words, when you’re right at the -4 key number in this six-deck scenario, feel free to double your initial minimum bet. Get the count to -2, and you can triple the table minimum. Find your way to a 0 count and make it 4x the minimum. And bet the maximum whenever the count reaches positive numbers.

Using the Knockout KO system correctly, even inexperienced card counters are capable of creating a player edge between 1-2%.

What Actual Players Are Saying About the KO Count

Researching and reading about card counting systems is an essential first step, but there’s nothing quite like firsthand experience.

You’ll be out there taking the Knockout KO count to your favorite casino sometime soon, but before you do, let’s see what actual blackjack enthusiasts have to say about the system.

Robert Leeroy Parker — author of Magnum Blackjack and frequent contributor to the Blackjack Insider Newsletter — had this to say while reviewing the Knockout KO system:

“Knockout Blackjack was published in 1998, and it has quickly become the second most popular system, undoubtedly due to its simplicity.”


“KO was viciously attacked by many when it first appeared. People simply could not accept that anything that simple could work.”


“However, extensive computer simulations have shown that KO and Hi-lo are neck-and-neck, with KO out-performing Hi-lo under some game conditions.”

Counting Cards Is It Worth It

In a review of the original Knockout KO book titled “Counting Cards Can Be Simple, This Book Shows the Way” — posted to Amazon by a reader named Richard from Florida — the average player’s perspective is captured perfectly:

“If you have tried counting cards using other systems and have failed, then Knock-out Blackjack is the book for you. Not only is the system uncomplicated, but the authors layout a step by step progression of easily understandable techniques.”

“The data supporting the K-O system is included in various chapters, yet you do not need to know or memorize the math. There is no dividing and they show you how to make a simple adjustment so you there are no negative number to work with. And it is easily adjustable to any number of decks.”

“When they say it is the easiest card counting system every devised, it is true. I have tried other systems and failed. But with K-O system the average person will have the advantage over the house for a change.”

Meanwhile, fellow Amazon reviewer Ian Jeffreys wasn’t as impressed, writing in “Authors Have Overstated the Method” that the Knockout KO system is overrated:

“The KO system presented in this book depends on a set of simulation data I’m sure the authors believe is valid, but shows serious evidence of sample bias.”


“Recent work done on optimal betting theory, which allows a fair comparison of blackjack systems, shows that the KO method is extremely weak. The claim that KO can, for example, seriously challenge the dominance of Bryce Carlson’s complex and powerful AOII system is just ridiculous…”


“Just look at some of the independent studies archived in the rec.gambling.blackjack archives to see how weak KO really is.”

Like I said, though, learning to appreciate any particular card counting method is all a matter of personal preference.

If you’re new to the world of advantage play blackjack, so-called “Level 1” unbalanced systems like the Knockout KO are the perfect entry point. You won’t have to get bogged down in maintaining dual counts or converting from running to true, which lets you focus on the task at hand — beating the house with well-timed big bets.

Of course, other systems out there have been shown to be more effective, but as a result, these counts are far more difficult to use in the casino setting.


The Knockout KO card counting system offers the perfect compromise between complexity and usability. Rookie card counters who find themselves struggling with some of the old-school balanced counts — most of which were invented by legitimate math geniuses — will definitely appreciate how the Knockout KO boils things down to basic addition and subtraction. And as you grow more skilled with your advantage play abilities, the Knockout KO system provides an effective jumping-off point toward learning the more advanced concepts.

If you’re interested in counting cards without dealing with intimidating math formulas, the Knockout KO system created by Vancura and Fuchs has everything you need to succeed.

Michael Stevens

Michael Stevens has been researching and writing topics involving the gambling industry for well over a decade now and is considered an expert on all things casino and sports betting. Michael has been writing for since early 2016. ...

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