Card counting is a technique used in casino games to try and work out the cards coming in the next hand.
But, while it may sound fairly straightforward, there's a lot more to counting cards in Blackjack than meets the eye.
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Mike Aponte, a former member of the infamous MIT Blackjack Team, takes us through the complicated process of counting cards.
He says: "I'm playing perfect basic strategy, keeping accurate track of the running count, converting that running count into a true count based on the number of decks remaining and then sizing my bet proportionally based on the true count."
Want to learn how to count cards like an expert? Take a look at the video above to find out all you need to know.