I have friends who are very into this and it is something I simply cannot understand. No one I know has ever won money in the long run, they all lose. Usually when you ask "How much have you won?" they will tell you "Oh, about $x" but what they mean is not how much they are up net in the long haul. They will get on a streak and keep betting until they are up about 1000 or so, then start losing and keep betting until they have to put more money in the account. That doesn't count as a loss to them though, they add that 1000 to the total. These people are both in denial to themselves and others about how much they have lost, its like they don't understand the concept that when you lose the money you won, you aren't "winning" at all. There are some of them who understand that they are losing but they don't care, they say that they bet because it makes sports more interesting, and these people seem to have the habit in a reasonable amount of control. The other's don't seem to realize it's never going to be "the next bet" that lets them cash out.