Casinos, card counters, and the law of large numbers

In movies, blackjack card counters confidently place huge bets in casinos when the time is just right, making huge profits. While counting cards can be used to profit from casinos, the truth of how card counters profit is a bit different. In this article, we get to the heart of how casinos and card counters manage their profits—the law of large numbers, a fundamental theorem in statistics. We discuss how card counting works and what this looks like in practice.