I am a little bit greedy, but I know when to stop or when my luck is over.
This make in the worst case i lost just 30% max. of the play money.
Most of the times i stop when I am at profit. Knowing tomorrow will be another day to win and bring some BTC home.
If you stop when you have profit is really good sign of self control. (most can't), most people keep on playing thinking they'll be winning more but they lose.