How to Count Cards in Blackjack Explained

Card counting is a system that can provide a long-term blackjack advantage. It involves counting card values and betting more money when the count is in your favor. Though it bears a reputation for being notoriously difficult to learn, in reality, card counting is not too complex when you break it down.

This page covers how you can quickly learn and successfully use a counting system. It also discusses how feasible this advantage-play technique is in today’s casino environment.

Blackjack card counting systems

Many card-counting systems exist. Each blackjack card counting strategy varies based on its accuracy and ease of use. Simple systems are easy to learn, but they don’t give you as much of an advantage. More complex systems provide a higher edge, but they’re more difficult to understand and implement.

As a beginning counter, you want a strategy that’s both accurate and simplistic. The Hi-Lo system provides the best of both worlds. When employed correctly, it gives you between a 0.5% and 1.5% advantage. It also doesn’t require painstaking hours to learn.

We encourage you to browse and consider other systems as you become a more confident counter. For the purpose of this blackjack guide, though, we’ll stick to the Hi-Lo system for all examples.

What is the point of counting cards?

When counting cards, you focus on the values and not the suit. Your objective is to determine when the shoe is rich in aces and 10-value cards. Two occurrences are more likely when the shoe contains a disproportionate number of 10s/aces:

You’re more likely to receive a natural blackjack (either 3:2 or 6:5 payout).
The dealer faces higher odds of busting when drawing to a hard/soft 17.

The idea behind counting is to raise your bets when the count is positive (i.e., richer in aces/10s). Meanwhile, you place the minimum bet when the count is neutral or negative (i.e., richer in low-value cards).

How do you use the Hi Lo system in blackjack?

Here’s an overview of how to count cards in blackjack using the Hi-Lo system. As you can see, this blackjack strategy is easy to learn and simple to implement.

Assigning a value to each card

The Hi-Lo system places card values into the following groups:

High value: 10 through aces = -1
Neutral: 7 through 9 = 0
Low value: 2 through 6 = +1

High-value cards coming out of the shoe hurts your chances of winning. Therefore, you subtract one from the count every time this happens. Low-value cards coming out helps your chances. When that happens, you add one to the count.

Again, the procedure is to place minimum bets until the count becomes positive. At this point, you raise your bets and capitalize on the favorable situation.

Tracking the count

You must track every card that’s dealt to be successful with the Hi-Lo system. You continue tracking cards from the beginning of the shoe until it’s shuffled. Here’s an example of tracking the count during a hand:

A new shoe begins.
Four players (including you) are at the table.
You receive A-5 = Count at 0.
Player 2 receives J-7 = Count at -1.
Player 3 receives 4-6 = Count at +1.
The dealer’s face-up card is 8 = Count still at +1.

Of course, additional cards will come out as players hit and the dealer draws more cards. You must be able to keep up with the dealer’s speed to successfully count. You’ll find this difficult at first. With practice and patience, though, you can make counting feel like second nature.

Calculating the true count

Most blackjack games feature multiple decks in the shoe. The Hi-Lo system requires you to account for all decks that have yet to be dealt. The true count provides a better indication of your advantage or disadvantage in a multi-deck game.

For example, a +4 count may indicate that the odds are highly in your favor. However, it could easily be diluted if only one deck has been dealt out of eight. To keep track, you’ll be tallying two counts during a game:

Running count: The count before you consider the number of remaining decks.
True count: The count after you’ve factored in the remaining decks.

Here’s an example of putting this concept into practice:

Your running count is +6.
You estimate that three decks remain in the shoe.
6 / 3 = +2 true count.

You can only guess how many decks are left in the shoe. Your accuracy in making these guesses should improve with experience.

Ranging bet sizes as the count rises

Counting cards alone doesn’t result in profits. At some point, you must increase your bets to capitalize on advantageous situations. Of course, you shouldn’t raise your wagers by random amounts during positive counts. Instead, you’ll want to follow a system that calls for progressive bet increases as the count rises.

Here are some rules for raising your bets along with the true count:

Start by placing the table’s minimum bet (e.g., $10) to minimize losses with unfavorable counts.
Set a unit size (e.g., $25).
Use the full $25 unit when the true count hits +1.
Increase your wager by another unit every time the count rises by +1.

Now, let’s look at an example involving units of $25:

You place the $10 minimum table bet.
The count rises to +1.
You now wager $25.
The count rises to +2.
You now bet $50.
The count rises to +3.
You now wager $75.
The count drops to -1.
You drop down to the $10 minimum wager.

Use bet spreads that minimize attention

A bet spread refers to the distance between the minimum bet and how much you increase your wager. This concept is important because it relates to how transparent your card counting will be to casinos. Here’s an example of a bet spread:

A table’s minimum wager is $10.
The true count goes to +4.
You increase your bet to $100.
100 / 10 = 10.
Your bet spread is 1-10 (1 represents the minimum bet).

Casinos differ in their tolerance of bet spreads. Some may not be alarmed when they notice a 1-10 spread, while others may closely scrutinize your play. You should play at casinos that allow anywhere from a 1-10 to 1-15 spread to make healthy profits. Avoid casinos with reputations for being quick to act on big bet spreads.

How much does deck penetration matter?

Deck penetration refers to how far into a shoe the dealer goes before shuffling. If the dealer goes five decks deep in a six-deck shoe, for example, then the dealer is allowing 83% penetration (5/6).

You want more deck penetration because it provides greater confidence in your count. For example, a +3 true count bears more weight with two decks left than five. Generally, 70% penetration or higher is optimal. Your true count is more likely to materialize with so much of the shoe already dealt.

Is it better to card count with a team or individually?

Many professional card counters work in teams. They use “spotters” spread out at different tables and track counts.

Spotters wait until a deck is “hot” (big positive count) and signal the “big player.” The big player, who starts by watching the action from afar, sits down at the hot table and starts betting big. A team-based approach accomplishes two main goals:

The spotters, who place minimum bets, look like ordinary gamblers.
The big player doesn’t need to spread bets and, as a result, looks like a high-stakes gambler.

The downside to team-based counting is that you’re only as good as the weakest link. Most teams experience trouble finding enough dedicated players.

Therefore, you may choose to act as a solo counter. This route is preferable if you’re a serious player who can’t find serious teammates. The downside is that you’ll need to spread bets. You stand an increased chance of being caught by the casino staff in this case.

What’s an ideal bankroll for card counting?

You can start counting cards with as little as $200 or so. However, your risk of ruin increases tremendously with a small bankroll. Despite what movies suggest, card counting is a volatile affair that doesn’t result in instant riches. At best, you’ll be dealing with a 1.5% advantage.

That being the case, you can expect to experience a mixture of profitable and rough nights. A large bankroll helps you stay in the game and continue using large bet spreads (i.e., 1-10 or higher) when the need arises. Here are our recommended starting bankroll requirements for solo counters and teams:

Solo counter = $6,000 to $10,000.
Team = $18,000 to $25,000.

These amounts don’t guarantee that you’ll survive the counting world. However, they greatly reduce your risk of ruin. Again, you can always walk into the casino and try counting with $200 or so. Your chances of survival diminish considerably in this case, though.

Can you still make money counting cards in a casino?

Casinos have modified rules over the years to hamper card counters. Nevertheless, counting can still be profitable under the right circumstances. Here are the basic conditions you should look for when researching casinos:

70% deck penetration or more.
1-10 bet spread or higher.
Low minimum bets (i.e., $5 or $10).
Casino staff that’s generally tolerant of potential counting activity.
3:2 natural blackjack payouts (versus 6:5).
Other player-friendly rules (e.g., the ability to double down after splitting).

Most casinos don’t offer this perfect mix of conditions. However, your blackjack odds improve when you get as close to the ideal standard as possible.

How does the number of decks in the game affect card counting?

The gambling industry started adding multiple decks to shoes in the 1960s. It was getting hit hard by card counters and needed a way to diminish pro players’ profits.

Additional decks do make life more difficult. They dilute your count and make it harder to tell when you hold the advantage. As explained earlier, though, you can account for extra decks by using the true count. You just need to be good at estimating how many decks are left in the shoe when doing the math.

Is card counting legal?

Card counting is perfectly legal. It’s a technique that relies on skill — not cheating — to win. However, most casino jurisdictions give gambling venues the right to refuse service under reasonable circumstances. Therefore, casinos can kick you out just because they don’t like you winning.

Pit bosses and floor supervisors are the main casino workers who look for potential counters. They make rounds and watch games to look for counters and other irregularities. You can reduce your chances of being spotted by pit bosses or floor supervisors by using the following tips:

Research casinos ahead of time to see which ones are most lenient toward counters.
Keep your bet spread reasonable (e.g., 1-10 to 1-15).
Wear different clothes and change up your appearance when playing at the same casino multiple times.
Talk with other players and remain relatively casual.
Work on your skills so that you can be casual and still keep an accurate count.

Is it possible to count cards at an online casino?

Deck penetration is a major part of successful counting. Again, you ideally want at least 70% penetration. Online casinos don’t give you anywhere near this amount of leeway. In fact, they offer close to 0% penetration.

Run by software, online blackjack games shuffle the shoe after every hand. Therefore, you can never enjoy enough deck penetration to gain an advantage by counting cards in online blackjack. Some live-dealer casinos offer up to 50% penetration. However, even this figure isn’t enough to sway the odds in your favor.

Famous blackjack card counters

Many gamblers have had considerable success with card counting over the years. The legends who made big profits before getting banned include:

Al Francesco: Inventor of the big player concept, Francesco paved the way for blackjack teams.
James Grosjean: Grosjean won the Blackjack Ball competition — an annual meeting of the world’s best blackjack players — so many times that he was asked not to compete again.
MIT Blackjack Team: The MIT Blackjack Team terrorized casinos throughout the 1990s and collectively won millions of dollars.
Keith Taft: Taft successfully used a computer to count cards before doing so became illegal.
Ed Thorp: Author of the 1962 book “Beat the Dealer,” Thorp taught millions of gamblers how to topple the house.
Ken Uston: Author of The Big Player, Uston provided a primer on team-based counting.
Stanford Wong: An accomplished author, Won invented a technique called “wonging.” It is no longer allowed today, and it involved counting cards off to the side of a game before playing.