5 Widespread Mistakes in Blackjack Card Counting

Card counting is an advantage play technique that enables sharp blackjack players to gain a long-term edge over the house. It involves tracking the ratio of high to low cards as they are dealt out by assigning value tags to different card denominations. The surplus of high cards is good for the players, while the prevalence of low cards helps the dealer.

The technique is not as difficult to master as the uninitiated think. Contrary to popular belief, card counters do not have to memorize each card that has been played out or be autistic savants like Dustin Hoffman’s character in Rain Man.

The only qualities required for mastering this technique are patience, discipline, tenacity, and some basic arithmetic skills. Any committed blackjack player can learn to count cards but most fail to generate long-term profits because they make way too many blunders at the tables.

So today, we shall spend some time discussing the most common mistakes rookie counters commit. Check them out if you are new to card counting as they may ultimately make the difference between losing and winning in the long run.

What follows is based on the premise you are already familiar with the rules of blackjack and how card counting works. If otherwise, we encourage you to take a step back and go through the basics of multi-deck card counting to learn the basics of this advantage play technique.

Mistake #1 - Using a Very Complicated Counting System

Card counting gained notoriety in the early 1960s when mathematician and blackjack researcher Edward Thorp unveiled the first point count system in his revolutionary book Beat the Dealer. Multiple card counting systems have emerged since then and blackjack experts typically group them into four main categories, Level I, Level II, Level III, and Level IV.

1Level I Systems

Level I systems use the tags +1, 0, and -1, so counters are only adding or subtracting by 1 and ignoring the neutral cards as zero. Hi-Lo is the most popular and broadly used level I system for blackjack.

2Level II Systems

Level II systems involve additional tags as cards are counted as +1, -1, +2, -2, or 0. While more accurate than Level I, these are more difficult to master. The Hi-Opt II and the Omega II both belong to this subcategory.

3Level III and Level IV Systems

Level III and Level IV systems further add to the complexity as the number of counting tags increases. The exact tag values vary, depending on whether the system in question is balanced or unbalanced.

As we just mentioned, a distinction is also made between the so-called balanced and unbalanced systems. The difference between these two subtypes is as follows:

4Balanced Counting Systems

Balanced counting systems are those where the count starts and ends at 0 if you go through a full deck of cards.

5Unbalanced Counting Systems

With unbalanced counting systems, the count starts at a number other than zero, for example, -2 or -4. They usually have a pivot point to indicate when exactly players must start raising their bets. The Red Seven is an example of an unbalanced system.

Card Value Hi-Lo Hi-Opt II Wong Halves Red Seven Revere 14 Count
Ace -1 0 -1 -1 0
2 1 1 0.5 1 2
3 1 1 1 1 2
4 1 2 1 1 3
5 1 2 1.5 1 4
6 1 1 1 1 2
7 0 1 0.5 0 or +1* 1
8 0 0 0 0 0
9 0 0 -0.5 0 -2
10, K, Q, J -1 -2 -1 -1 -3
Level Level I Level II Level III Level I Level IV
Balanced/Unbalanced Balanced Balanced Balanced Unbalanced Balanced

*The Red Seven system keeps a side count of the sevens. Sevens of diamonds and hearts count as +1, whereas the sevens of clubs and spades count as 0.

Complex Systems Are More Efficient
Complex System Could Result in More Errors
Stick to the Good Old Hi-Lo

Mistake #2 - Messing Up the Running Count


Professional blackjack player Don Johnson famously said “Monkeys can count cards”. But as easy as learning to count seems, players still require sufficient preparation before they can implement it effectively. Rookies often struggle to keep a running count and convert it to a true count in the noisy casino environment.

It is not uncommon for novice counters to commit costly errors in the running count (RC), which ultimately prevents them from becoming winning players. Maintaining an accurate running count is vital if you want to beat the house at its own game. Below are three of the gravest RC mistakes you can commit while counting cards at the blackjack tables.

2You Forget to Update the Running Count

Forgetting to update the running count as you are playing out your hand is a major mistake that can cost you dearly over the long haul. You have to maintain a correct RC at all times, taking into account each card that leaves the shoe, or else you are doomed to failure.

Updating the RC is the first thing you should do after a card hits the felt. You should do it before you add up your hand total, before you consider a basic strategy move, and cheer with fellow players after the dealer busts.

3You Miscount the Dealer’s Exposed Card

Another common way for novices to mess up the running count is by miscounting the exposed card of the dealer. There are several ways for this to happen and all of them could completely destroy your positive expected value in the long term. Some rookies altogether forget to count the dealer’s exposed card.

Others count it two times – once after the initial deal and again, after the dealer flips over the hole card to complete their hand. Either way, this is a serious mistake you should uproot as early as possible. Remember to count each card that hits the felt no more than once.

4Mistaking One Card Denomination for Another

As strange as this may sound, novices sometimes mess up the running card by confusing one card denomination for another. This commonly occurs with the 9s and 6s when players count them by looking at the bottom corner of the cards. You can easily confuse the two denominations when you see them from this perspective because they are reversed at the bottom.

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Mistake #3 – Counting Games with Poor Playing Conditions

Counting Games with Poor Playing ConditionsSavvy players always familiarize themselves with the playing conditions a given table has to offer before they take a seat. We have heard some counters argue they play subpar games for lack of choice as there are no casinos with friendlier conditions in their vicinity.

However, we consider this a flimsy excuse as the main (or should we say the “only”) purpose of card counters is to generate positive expected value.

If the conditions in your local casinos prevent you from doing this, you will be better off not playing at all. Otherwise you are just throwing your money away with both hands. Smart players will never settle for the rules we list below:

  • No doubling after splitting pairs
  • No doubling on soft hands
  • Doubling only on two-card totals of 9, 10, and 11
  • Splitting only once to a maximum of two hands
  • The dealer hits soft 17 rather than standing
  • Even money payouts for blackjacks
  • 6 to 5 payouts for blackjacks
  • Insufficient shoe penetration
If you play multiple-deck games, you should never bother with tables where the dealer does not give you a deep enough penetration. Avoid games where the cut-card penetration is 50% or less as you will only be wasting your time and money. You need a combination of friendly enough rules and a shoe penetration of at least 75% to count multi-deck games efficiently.

Mistake #4 – Confusing True Count with Running Count

Confusing True Count with Running CountThis is another widespread mistake among rookie counters who have not practiced sufficiently before attacking the tables in a real casino environment. As is to be expected, this blunder has a devastating effect on their long-term expected value.

If you are reading this, perhaps you already know what the difference between running and true count is, but we shall revise it briefly for the uninitiated.

1The Running Count

The running count is the running tally of each card’s assigned tag (+1, -1, and 0 in Level I systems).

2The True Count

The true count takes into account the number of decks in play as most blackjack games typically use multiple decks. To determine the true count, players must divide their current running count by the number of decks that remain to be dealt.

You make playing and betting decisions based on the true count and should never confuse it with the running count. This is how one such mistake looks and we assure you the consequences of making it will not be pretty. The example below is derived from a blackjack game that plays with six decks in total.


Approximately 5 out of 6 decks remain in play.


The player has arrived at a running count of 15 at this point.


The true count is 15 / 5 = 3.


The player sizes their next bet based on a true count of 3.


The player then replaces the running count with the true count.


They start adding to the number 3 as cards continue to leave the shoe, ultimately messing up both their running and true count from this point on.

This is a grave not to mention a very costly mistake as one such player would continue to size their bets and deviate from basic strategy incorrectly based on an inaccurate count. If you ever catch yourself doing this, try to repeat the current running count in your mind to prevent yourself from replacing it with the true count.

Mistake #5 - Overbetting and Underbetting

And finally we arrive at the subject of bet sizing and betting proportionately to your bankroll. Here it is important to mention that overbetting and underbetting are both equally detrimental for the advantage player.

Overbetting Your Bankroll
Underbetting Your Bankroll