I think seasoned casino players will typically observe the stack sizes of the players at a table. Stack size is a critical factor in poker, as it directly affects the types of hands a player will play and the moves they can make. Players who have deeper stacks are usually more comfortable and are inclined to play more aggressively, while those with smaller stacks will be more conservative and careful not to lose their chips. Hence, observing stack sizes can help a player to make informed decisions about their bets and moves, and ultimately increase their chances of winning.