Casinos have responded in two different ways. The first is to make card counting more difficult. Many casinos shuffle six decks of cards together—automatic shufflers do the work—and only deal two-thirds of the way through the decks to reduce the player’s probabilistic advantage. Or they shuffle after every hand. In both Las Vegas and Atlantic City, pit bosses are known to come around and engage suspected card counters in conversation to both distract and intimidate them.

