Words of wisdom from Jeff Jonas:

Circa 1993 we were building the first NORA (Non-Obvious Relationship Awareness) system for a casino. In this system the first relevance rule was basically: “Tell me when the bad guy is the good guy.” This one rule was created to detect and alert for such things as: the slot club loyalty card member is banned from gaming (on the Nevada Gaming Control Board’s Excluded Persons List) or the job applicant is a known gaming felon.

The second relevance rule was: “Tell me when the bad guy knows the good guy.”

With just these two rules, the system started kicking out all kinds of valuable, unanticipated insight including one of my favorites: An alert surveillance room operator noticed a dude cheating on a roulette table … making bets after the ball fell (called “past posting”). Dealers are supposed to watch for this. But somehow today this dealer kept missing this obvious scam. Casino security detains the cheater. The dealer says “I can’t believe this happened to me, I am so embarrassed, you surveillance folks are sure doing a good job, it won’t happen again.” During the arrest processing, the cheating player provided a different last name and address than used by the dealer. Fortunately, the cheater provided his real home phone number which happened to be the same number that the dealer had used on her original employment application.

The dealer pretending, up to this point, to not know the player rolled-over in an instant and confessed when NORA popped off a real-time alert: “The cheater is related to the dealer.”