Card counting is not all that hard to do (I can get you up to speed in a couple months). But it’s a lot easier, and a lot more profitable, when you have a computer in your shoe that has been programmed to do all the work.

From the early 1970s until the mid-1980s, when casinos deemed it illegal to have high-tech helpers at the tables, savvy advantage players made their money with the assistance of various computers worn on their bodies. Some of the gizmos shuffle tracked (which is recognizing clumps of cards in a deck, based on previous cards dealt and the type of shuffle being used; it allows you to accurately predict the coming cards) and others executed the much simpler task of card counting.

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