Shuffle tracking in blackjack is a technique where skilled players track specific groups or clumps of cards through the shuffle process, allowing them to predict when favorable cards (like high cards) will reappear. Players focus on the shuffle to identify these clumps, then adjust their bets based on when they expect these clumps to be dealt. If a player is particularly focused on the shuffle or changes their betting pattern after the shuffle, it could indicate they're using this method. Shuffle tracking relies on the ability to observe and track the dealer's shuffling style and predict card groupings, making it a complex and often subtle form of advantage play. However, it’s hard to master and can lead to a player being banned if detected.