However casinos long ago figured out the techniques of card counters, where they bet the minimum through the beginning of the shoe, and then when they figure the odds are good, substantially increasing their bets. Pit bosses would watch a table, and when they noticed a ‘minimum bet’ bettor suddenly playing rich near the end of a deck, they escort him to the door. The MIT Blackjack team figured out that if they divided up the responsibilities of card counting and capitalizing on hot decks, they could pull off the strategy without arousing the suspicion of the casinos.
A counter would park themselves at the table and count the deck as it played out. When it was in an advantageous position, they would signal a partner to come over and start betting big. The big betting player would learn the count through a codeword from the counter. The big player would then start betting big until the deck exhausted itself. It seemed to work fairly well.
And according to Mezrich, it worked for a couple of years until one of the security firms that consults to all the casinos made their crew and started circulating their photos to every casino from the Bahamas to Canada. Defeating it isn’t that hard for the casino though, and one would suspect that apart from the fact that they know to look out for card counting teams working casinos now, they also have a few other techniques available to them.
One way to defeat a counter is to cut the deck deeply so that the number of unknown cards in the deck is too great to accurately estimate the number of facecards likely to come up. When you see someone put the brightly colored card into the deck to mark when it’s up, if they put it in closer to the middle than to the end of the shoe, that’s “cutting deep”. Another way to defeat the counters is simply to watch them work multiple tables and throw them out when you see them do it.