How Casinos Catch Card Counters

While the act of counting cards has enjoyed a special place in television shows and movies, the reality of this tactic is far less glamorous. Primarily used in the card game blackjack, counting cards involves memorizing how many cards are left in a deck (or multiple sets of decks). This can have significant importance and financial ramifications when gambling on games of blackjack. As Vivek Desai, a mentalist, illusionist, and card counting consultant for casinos, explained to Vice, "Card counting is a combination of mathematical skills and good memory."

The reason people are more likely to try and count cards in blackjack over other casino card games comes down to the way the decks are treated during the course of playing. Desai explains, "Counting comes into the picture when you start eliminating cards because blackjack is a game where the past directly influences the future, unlike poker [...] where the cards are shuffled back into the deck. In blackjack, every time you use a hand, it's thrown away, so that means you have lesser cards in the deck."

It's important to realize that counting cards isn't illegal. However, if a casino discovers or even suspects you might be counting cards, it'll eject you immediately. Even worse, many casinos won't let you cash in the existing chips or credit they make you use in the casino so you could lose any money you might have started with or earned before you were caught. If you're wondering how a casino might discover a person counting cards, let's dive in.

Oftentimes, card counters will give themselves away through specific behaviors while they're at a gambling table, which means that a keen eye from a casino's security team can make easy work of identifying potential card counters. As casino consultant Vivek Desai explained in an interview with Vice, card counters tend to work in teams before. Specific behavioral examples, according to Desai, "[Card counters] are almost always focusing on the game, they don't make conversation or consume liquor during the game, and you'll always see them looking intently at not just their own cards but others' too."

If you find yourself wondering why looking at another player's cards would be a giveaway of card counting, note, it's the ultimate goal of blackjack. Since you, as a player, are playing to get a total of 21 (or the closest possible number under 21), you're only really playing the dealer and not the other players at the table.

You might also be surprised to learn that one of the best ways to detect a card counter is to actually learn to count cards yourself. Since the betting patterns of individuals at a given card table will be similar if they are counting cards, then by counting yourself you can compare what kind of betting you would do against the person suspected of card counting. Casino security staff are often trained in counting cards as a way to monitor and compare the betting behaviors of players on the gambling floor.

Even if a card player is suspected of counting cards, it's not always easy to prove. To catch them, casinos will often employ specific change-ups to track the reaction of a suspected card counter. For instance, having the dealer shuffle the deck after players have wagered higher bets to gauge their reactions. This can also include tracking how players bet on subsequent rounds, whether or not they get a sudden phone call or need to leave the table suddenly, and even if they start at a new table playing only minimums while they begin the counting process over again.

Many casinos also use facial recognition software, enabling them to access large databases with photos of known card counters. This means that even if a card counter is new to one casino, if they were caught counting cards somewhere else, the chances are good that they're in a database, which means any casino they visit will more likely be able to identify them as a card counter from their arrival.

In addition to employing previous card counters, and training security staff to learn card-counting techniques, many casinos also use specific software that's designed to track and detect card-counting behaviors on a casino floor. Also, even though card counting isn't technically illegal, someone with multiple offenses could lead casinos to press charges and/or get law enforcement involved. While punishments for these kinds of misdemeanor crimes generally involve fines, some can include jail time, especially for repeat offenders. With that in mind, it might be better to stick to sports betting.