They will probably not allow this fine article explaining exactly how they do limit and keep track of players expertise (which they refer to as MSF [maximum stake factor]) and even have players bets color coded regarding their desirability or not and even the location of where the wager was made, which all goes in to whom is limited or barred from playing, but I would venture to say that most will learn something by perusing this article. I will print the link below, but read the entire article and I think you will find it insightful, especially considering the volume of posts quizzing people on how to not get flagged or collared when playing at some books. That is, if the moderators don't erase this.