What are the black marks on the faces of cards at the casino?

I play 3 Card Poker at an indian owned casino in Louisiana. I've noted that cards from the Ace/Jack all have marks on the face of the card. They are black marks on the edges of the face of each card. Why are these cards marked as such? A friend suspects they're marked so the shufflers can some way distinguish face cards from lesser cards. If that's true I would suspect the casino could manipulate the shuffle.

I thought that was so a dealer could check for a blackjack using an optical scanner rather than bending the cards and risk flashing the players. I could be mistaken since I'm not a dealer.

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Quote: Acklafan

I play 3 Card Poker at an indian owned casino in Louisiana. I've noted that cards from the Ace/Jack all have marks on the face of the card. They are black marks on the edges of the face of each card. Why are these cards marked as such? A friend suspects they're marked so the shufflers can some way distinguish face cards from lesser cards. If that's true I would suspect the casino could manipulate the shuffle.

I'm not familiar with the marks you're describing (and I don't deal at an Indian casino) so I really don't know. However...

All modern shufflers that I'm aware of have OCR (optical character recognition) capability and don't require any special markings to distinguish the cards. Yup, the shuffler can tell you if a card is missing and which one it is. Some shufflers can sort the cards back into the original order, shufflers on single deck games (like 3CP) are the most likely candidates for this ability.

Does this mean the casino could manipulate the shuffle? Sure, anything is possible. But it's really unlikely considering what they'd have to lose (as well as the shuffler manufacturer as they would almost have to be complicit). Think of it this way: Casinos have had a house edge for centuries without rigging a shuffler (which have only been around for 20 years or so), so why would they risk the license on a multimillion dollar facility to increase it a little bit?

If you still think the game is rigged in light of this the best course of action would be to stop playing.

These are the marks I saw:



They were only on the high cards, and seemed to be the same for each card. It didn't look like they differentiated between the cards or suits, just high cards had them and 9 and under didn't.

If you'll note, the Aces have them in the left corner, the 10 and faces have them in the right corner.

When the BJ dealer sees the black spot on the up card, he pushes that corner of both into the scanner. If the dealer has BJ, the scanner sees the black spot and lights the red light. If not, the scanner sees white, and lights the green light.