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  • Willy Allison

The Resurgence of Marked Cards

According to the Chinese, 2013 was the year of the snake. From a game protection perspective you could have called it the year of marked cards. An unusually high number of cheating cases involving marked cards hit the news last year. Among them was the arrest of high profile Las Vegas gambler Archie Karas. Another player was arrested in two States and labeled a “serial card cheater” by the media. Two dealers in a major East Coast casino were accused and charged of marking cards for players on a baccarat game.

So are we on the verge of a card marking zombie apocalypse or should we ignore the whole thing like the Korean guy who sang “Gangnam Style”?

Before I offer my take on this, lets start with a little perspective. 1) Card marking isn’t new. If there were a Mount Rushmore of cheating techniques it would be Abraham Lincoln. It’s always been a threat in table games and until we make table games digital, it always will. 2) There are a gazillion ways to mark cards. However, recently some cool stuff has emerged. New technologies are allowing cheats to run wild with their imagination. 3) Card marking is not hard to detect - if your staff pay attention.

Card Marking Isn’t New

There is a lot of information out there on how to mark cards. A lot of it is written for Chris Angel wannabes, bored college students and wise guys who like to cheat their friends in private poker games. In a casino environment it’s a little tougher to get away with it regardless of how easy the authors of such information may imply. However, indications are that it may be getting easier.

In casino land it is not uncommon to see players marking cards using the most simple of techniques. They’re embarrassingly low tech: card bending, nicking, scratching, knuckling and finger nailing. All names that are self-explanatory. One of my favorite card marking moves is the chip indent . It’s a great way to mark cards on games where players are not permitted to touch the cards. The cheat simply uses his chips to mark cards. The move usually takes place during the dealer’s “take & pay” procedures. While the dealer is engaged in the payout process, the cheat under the premise of placing the chip as a wager for the next hand, will take the edge of his chip, lean forward and place an indent on the target card as it lays face-up on the table. Cheats have also been known to use this technique under the premise that they are giving the chip to the dealer as a tip. I’m guessing any suspicion by the dealer of foul play was quickly overcome by the gratuitous gesture from the player.

I remember my first card marking observation in Surveillance. It was a guy playing double-deck blackjack. He was sticking his fingers in his ears and using earwax to mark the backs of tens and aces. Moral of that delightful story: throw away the books. Cheats don’t play by the book.

Chemicals & Concoctions

That brings me to “substance abuse”. Although earwax and other bodily fluids are readily available and accommodating to the low budget low-life, they’re not as sexy as chemical substances and the so-called invisible inks. An online cottage industry has sprung up over the last few years where anyone can buy chemical substances that can be used for marking cards.

The most common substance is daub. Mainly used by magicians, it’s a substance that can be smudged on a card that allows only the trained eye to see. It is not invisible but it is very difficult to detect unless you know what you’re looking for. You can buy the stuff online for around $50. Most vendors suggest that their products should only be used for entertainment purposes only. I guess gambling is entertainment.

If you want to step up to the sports car of card marking systems try the new high tech invisible inks. The word ink is a little misleading. These are substances that are concocted by guys that like to blow things up. This stuff is going for big bucks. I’m talking hundreds, even thousands. Vendors use cool names to market their magic concoctions but give very little detail on what the stuff actually is. Regardless of whatever the stuff is - it works. It’s undetectable to the human eye unless you view it through a special lens.

In the old days, the most common invisible ink marking systems were ultra violet (UV) based. UV chemicals were used that could only be viewed with a UV lenses or lights. You could spot those guys a mile away. They were the ones with the rose tinted sunglasses who should have been arrested by the fashion police. To combat the threat we went out and bought UV black lights and introduced them into our card inspection processes. If we suspected someone was marking cards we simply waved the light over them and the cheat was busted. It didn’t take long for cheats using UV marking systems to give up the caper once they knew we had the equipment to detect the markings.

But that was so 80’s & 90’s. Nowadays cheats are exploring new high-tech card marking systems. The method that is hot right now is infrared (IR) card marking. Without getting too scientific, IR basically works better because a UV light will not detect the markings. Casinos should not make the mistake of relying on UV lights only to detect marked cards these days. Cheats will take advantage quicker then management can say, “ U can’t touch this”.

Infrared substances cannot be seen with the invisible eye, a UV black light or a standard surveillance camera. IR chemicals can be purchased that can only be seen at 900 nanometers on the visible light spectrum. This makes detection almost impossible. To see the markings, a player has to use a special IR lens usually fitted in a pair of glasses or contact lens. Often they look like designer glasses and don’t draw as negative attention from fashion police. The contact lens used to identify the markings look just like normal contact lens. Don’t expect a cheat using IR contact lens to look like Michael Jackson in the “Thriller” video.

What’s in it for the Cheat?

So why do cheats mark cards? What is the return on the risk? Lets face it, marking cards doesn’t guarantee the cheat will win, however it does offer inside information that can lead to a pretty sizable advantage if betting and playing strategies are adjusted to exploit the information. There are 3 reasons a cheat marks cards: 1) to gain knowledge of the first card out of the shoe for determining bet size, 2) hole card knowledge and 3) next card knowledge for hit & stand decisions.

Here’s some of the ways cheats can gain an advantage by marking valuable cards on some of our more popular games:

Baccarat: Mark the high cards 6-9. If the first card out of the shoe can be identified as a high card - bet the Player. If it’s a low card - bet the Banker. A player’s overall advantage if they bet this way for the entire shoe is almost 7%. Alternatively, to save time but still gain a reasonable advantage, just mark the 8’s & 9’s.

Blackjack: Mark the Aces & 10’s. Sit on the first box to allow you to get the first card out of the shoe. Whenever it’s a 10 you have about a 13% edge over the dealer. If it’s an Ace, you have a whopping 52% edge over the dealer. Hole card and hit/stand knowledge can also be exploited to gain an edge.

Mississippi Stud Poker: Mark the Jacks. A player can gain an edge of about 38% if they adjust their playing strategy. [ref: Dr Eliot Jacobson’s website for playing strategies

Three Card Poker: Mark the Aces, Kings & Queens: A player can gain an edge up to16% if they adjust their playing strategy.

Caribbean Stud Poker: Mark the Aces and Kings. A Player can gain an edge of about 7% if they adjust their playing strategy.

Scary New Technology

Right now there is some scary technology coming out of China that incorporates IR marked cards, concealed cameras and computer analyzers. Combined to create a high tech card marking system, I must say that this device could do for cheats what silicon did for the cosmetic surgery business. The devices are being marketed as poker analyzers.

The technology works like this. The long edge of every card in the deck is marked with an invisible IR marking. Each mark identifies an individual card. In collusion with a poker dealer, the special marked deck is swapped into play. The player sits opposite the dealer on the table. He positions a concealed camera on the table (usually disguised as a cell phone). The camera has an IR lens that is used to transmit an image of the edge of the deck of cards to a small computer located in a smart phone (the poker analyzer) in his pocket. The image is transmitted during the period after the dealer has shuffled the cards and the deck is resting in front of the dealer before they are dealt to the players. The IR snapshot of the cards looks like a barcode. The poker analyzer identifies every card in the order that they will be dealt to the players in less than a second. A computer generated voice message is sent to the player via a Bluetooth mini earpiece communicating the rankings of all the hands on the table.

The device is constantly being improved to cover a variety of games, be even more easily concealed and to increase the range of the distance the camera can be away from the cards.

The hard part of pulling the scam off is recruiting the dealer. Not really. Nowadays, employee collusion in casinos is as common as insurance commercials on TV. A sad byproduct of the reduction of supervisor levels on the floor and an ethos of literally giving the gambler what ever they want.

The question we have to ask ourselves is could this technology and card marking system be used to cheat in other table games we offer like baccarat and blackjack? I say yes. Recruit the dealer and control the table. The capabilities to beat other card games in the casino are only limited by software design.

Time for an Eye Test

Here’s my take. Last year we caught a few cheats that arguably weren’t the sharpest tools in the shed. They got busted using chemicals to mark cards. I suspect they were like kids with new toys. The good thing is they brought attention to the development of new cheating technologies that should be taken seriously by game protection professionals around the world.

Generally over the years the casino industry has been able to keep a reasonably tight lid on card marking. Dealers, floor supervisors and pit managers used to be trained to be vigilant and on the lookout for indications players were marking cards. Reductions in floor supervisor levels, a lack of proper job-specific specialized training and a generally lower management emphasis on game protection is arguably providing more opportunities for organized cheats.

Moving forward, I suggest a casino’s strategy for combating the threat of card marking should include a two-pronged attack combining an old school and new school approach.

Old school approach: Train all staff in Table Games and Surveillance to recognize the tells”of a card marker. Watch player’s hands, in particular their fingers. The same goes for dealers. Let’s not forget that dealers have the ability to mark cards and collude with players. Watch the betting strategies of players. Are they betting in correlation with a first card advantage? Do they appear to be playing with hole card knowledge? Are they varying from basic strategy on blackjack? These are all indications that mark cards may be in play.

New school approach: Surveillance, this one’s for you. If you suspect someone is marking cards, it’s time to fight fire with fire and bring in a little technology of your own. Put your black light back in your holster for a moment and consider this. Most surveillance cameras, in their natural state actually have infrared viewing capabilities. The problem is the picture is not so good so manufacturers add a cut filter over the CCD chip to block out infrared light. The good news is the cut filter can be removed to convert it into an IR camera. A number of major surveillance camera systems provide end-users the ability to remotely change the IR status of the camera via the operator’s keyboard. This allows the operator, who suspects someone is marking cards at a table, to use a PTZ camera assigned to the table to switch to IR mode so the cards can be checked live on the game. If you currently don’t have this feature, speak to your manufacturer.

My Final Thoughts

I’ve heard of cheats using radioactive chemicals to mark cards. What next – DNA? As some experts have told me, there’s no one method of detecting all the possible chemicals that could be used. This is why in my opinion the old school approach of paying attention to how the game is being played should be first and foremost in any game protection strategy to combat marked cards.

In saying that, like organized cheats, we should be proactive in exploring new technology opportunities. When you look at the development of products like Google Glass, it isn’t hard to imagine that one day we may all be wearing contact lens to help process information more quickly and accurately. The key to many emerging analytic technologies will be cameras and lens. The ability for computers to analyze images from video to provide useful information is exciting. Smart camera technology could be a game-changer. Mark my words.


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