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How Casinos Know That You Are Counting Cards

03/12/2015 02:32 pm ET | Updated May 12, 2015
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How do casinos deal with card counting?: originally appeared on Quora: The best answer to any question. Ask a question, get a great answer. Learn from experts and access insider knowledge. You can follow Quora on Twitter, Facebook, and Google+.

Answer by David Shi, Former Blackjack player

It comes in levels. They have a lot of tools against card counting and I've experienced many to most firsthand. At the end you just get banned from the casino, or banned from table games. No, there is no backroom, unless you play somewhere you shouldn't be playing in the first place.

What the casino might do in steps to bar you

After each shift the dealer may approach the pit boss and tell him/her about counting suspicions. This is why when the dealer leaves, look for where he goes and if he tries to point to your direction. They have to shout out things that are strange to the pit as well such as "splitting 10's" and "making plays" (doubling previous bet which they say something like "checks play").

The pit boss also observes play just by walking around. If he sees huge bet spreads (you start out with a 1 unit bet, and then start playing 2 hands of 4 units, or 1 hand of 8 units), he might take the discard tray and count cards backwards to see if your play correlates with the cards that have come out. He may also walk up to you and start talking to you and acting too friendly to mess up your concentration. This is why some people don't always start out with 1 unit bets. They might switch between 1-3 unit bets, or the last bet from the last shoe. Also this is why counters train their skills up so that counting is second nature, so that when they do get "harassed" nothing happens.

When the pit boss suspects something, he might use the phone and call the security for a skills check. They turn the cameras on you and may analyze your previous play, [and see] if you are in the system. If you're in the system, the pit boss may also mark you as a counter in his or her notes (play unrated if you count). The security employed by the casino is basically retired card counters and the like so they can tell easily who's counting and who isn't. Now they assess if you're a threat or not. If they think you're a threat to the casino, then they come down with a group of people, tap you on the shoulder and tell you that you're too good for the game.

Then they might share your information/picture (they have footage of you playing when they analyze your skills) with other casinos. Then you'll find out you're banned from other casinos before you even play there.

What the casino might do to prevent people from trying to count

They can easily deter counters by making the game not fun for [them]. This is done by taking away their advantage. They can do the following, but at the same time also steer regular players/bad counters away from their games.

  1. Make the rules worse. Remove doubling after split. Remove late surrender. There's many things that they can do to increase the house edge. If they change the blackjack payout to 6:5, then I don't think any counters would play unless there's 0 heat, a single deck, and the deck penetration is 90%. Regular players know that bad rules equals less winnings too, so some would be less likely to play. Even if you don't count cards, look at the rules in a casino to see if they have bad rules. If the house edge is more than 0.5%, then it not be worth playing.
  2. Use automatic shuffling machines. This basically makes counting useless and the only plays that can be made are choosing between standing/hitting 16 against a 10. If the deck resets, then the shoe will never be good enough for a player to raise bets. Most players and sometimes dealers hate these machines too. Using too many would be bad for business. I sometimes play them to relax though and for cover play.
  3. Set the cut card earlier. Normal players might not care much about deck penetration, which is how many cards are being played, but this is very important to card counters. The more cards that are played before a reshuffle the better. This is also why shuffling machines are bad, because their deck penetration is about 2%. Many people don't play unless the penetration for 2 decks is over 55, and 6 deck is 75% or higher. They can also shuffle when they feel like it.
  4. They can mess with the min/max on the table, or set a rule just for a certain player. They can tell you that you can only bet10 instead of varying your bets from10 to1000. They can also change the bet limits from25 to5 or to100. This is less seen because other players might assume the casino is bullying another player, or the minimum bet is no longer fun to play in.

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