it can mean any of several things:
-something that breaks a string of luck for someone. so it cools off the hot streak. (this is most likely what matusow meant, which is what i guess you're referring to).
-a pre-arranged deck, as done by a blackjack team or anyone else. (probably not what matusow meant)
-the worst gambling movie ever, starring william h. macey and maria bello.
link
