The 5 Worst Card Counting Mistakes and How to Avoid Them

Blackjack Table and Drinks at a Casino
Counting cards is my favorite advantage play technique, and for most people, it’s way easier than you think. If you can add and subtract by 1, you can count cards.

That doesn’t mean it’s easy. It’s just easier than you would think if you watched Rain Man or 21 or something. There’s a common misconception that card counters memorize the cards that have been played or predict which cards are left in the deck.

This is only partially true. Card counters actually track the ratio of high cards to low cards in the deck by giving high cards a value of -1 and low cards a value of +1.

High cards are better for the player because they increase the probability of getting a “natural,” which pays off at 3 to 2 odds. Low cards are worse for the player because they increase your probability of going bust.

So, if you can find a deck that has more 10s and aces in it, you can raise the size of your bet and turn that house edge into a player edge. The trick is to avoid the following five card counting mistakes.

1 – Trying to Count in a Casino Before You’re Ready

Counting cards is easy in theater. The first time I read a book about how to count cards, I thought I was ready to get started. After all, I can recognize a high card from a low card, and I can add and subtract 1 like no one’s business.

The problem is that this is harder to do than I thought. Casinos are loud, distracting places, and blackjack tables get the hands dealt and played faster than you think. Even at a table with four other players, you’ll see 70 hands per hour. That’s more than a hand a minute.

People Playing at Blackjack Table

So, how do you get ready? First, practice at your kitchen table using a single deck of cards. Count through it one card at a time until you wind up with a count of 0 at the end.

Then, time yourself. Try to beat your time every time you practice. Move up to flipping over two cards at a time. Keep timing yourself, and make sure that your count is accurate. As long as you’re using a balanced card counting system, you should always end up with 0 when you get to the end of the deck.

Be sure to practice where there’s some noise. Play the radio, the television, and let the kids play. The casino is a loud, distracting environment, so you shouldn’t practice in a quiet environment.

You should also practice not doing anything that would let anyone know you’re counting. This means you need to be SO good at this that you don’t even look like you’re concentrating.

2 – Having Too Small a Bankroll

The thing about counting cards is that even though you have an edge over the casino, it’s a small edge, and you need to be able to survive a losing streak without going broke.

Card counting is a long-term proposition, and in the short run, anything can happen. Losing streaks can be far longer than you’d ever expect. The bigger your bankroll is compared to your average bet, the less likely you are to run out of money before that happens.

If you’re aggressive and have a high-risk tolerance, you can get by on a 200-unit bankroll. This means that if you’re betting $5 per hand, you should have at least $1000 set aside for your blackjack endeavors.

But you have a 40% probability of going broke if you do. If you get up to 1000 units, you reduce your probability of going broke to less than 1%.

Of course, these “risk of ruin” figures assume that you actually know how to count cards well enough to get that edge over the house.

3 – Getting Drunk

My niece recently took her driving test, and there was a section on the test about drinking and driving. The test question asked about the first thing that would be impaired when you were drinking.

The correct answer was judgment, not balance, eyesight, reflexes, or anything like that. Counting cards and playing blackjack with an edge over the house requires excellent judgment.

Some of this requirement is obvious. You must be able to count well enough to know when to raise your bets. You must be able to play with perfect basic strategy.

King of Spades Inside Champagne Glass

But some of the less obvious judgment calls have to do with knowing how to behave or recognizing when someone has noticed that you’re counting and it’s time to go. These are things you can’t do if you’re drunk.

My suggestion is to have a firm handle on how much you can drink before your judgment is impaired. Anything beyond one or two drinks is just denial on your part.

4 – Not Knowing Basic Strategy

Of course, good card counters know when to deviate from basic strategy based on the count. But you can’t deviate from basic strategy if you’ve never learned it.

And even if you never deviate from basic strategy, you can make money counting cards just by raising the size of your bets when the count is positive.

If you can’t be bothered to learn basic strategy, you have no business playing blackjack at all, much less trying to count.

It’s easier to learn than you might think, too. There are pages on this site that explain the basics, and you can find charts and tables galore with the correct moves, too.

5 – Staying in One Place for Too Long

Okay, so if you haven’t figured this out yet, you should realize it now. Casinos frown on card counting. And the easiest way to get caught counting cards is to stay in one place for too long.

Counting cards will work a lot better for you if you adopt a hit and run strategy. Never play at a casino more than three times a week. Never spend more than an hour in a given casino. Try to play during different shifts during your three visits.

And pay attention to whether anyone is paying a lot of attention to you and your play. At the first hint of heat, cash out and leave. Don’t wait around to get backed off.

On the other hand, you’re not really a good card counter until you’ve been backed off and barred from at least one casino. It’s inevitable. Even if you stick with a hit and run strategy, you’ll eventually catch some heat. That’s the nature of the endeavor. Try not to let it stress you out.

Luckily, in Vegas anyway, the days of getting dragged into the basement and being roughed up by security are ancient history.


Counting cards is a fun way to make blackjack more interesting, and if you want to play a game with a mathematical edge over the house, this is one way to do it. You just need to understand common card counting mistakes and learn how to avoid them.

This means you must know basic strategy cold, and you must be able to effortlessly and quickly count through a deck while looking like you’re not paying attention.

You also need to stay sober and avoid staying in one place for too long. Common sense goes a long way, but make sure you’re ready before starting your card counting career.