yeah, adding decks completely changes the game.
im guessing but id imagine speed of play and the size of your bets/how often you drop large bets is a tell tale. Someone sits out a bunch of hands, starts playing at the end of the round or "shoe" and then starts dropping huge bets here and there in favorable situations.
aaah I see. I was gonna say maybe itd
be smart to just keep moving, but it probably takes a while to count the cards. So when it comes to card counting, all the casino can really do is boot you and ban you right, do people face criminal charges for that?