One of the most important factor of a successful gambler is to know when to stop, most gamblers expecially the addictive type don't even know what is stop when it comes to gambling. So it's very important to;
* Stop when your losing is now getting to you.
* Stop when you are now feeling as is you can't do without gambling.
* Stop when you have a big winning, by channeling the money somewhere else so you won't lose it back to gambling.
* Stop when you are not even winning at all, it's not your thing.
* When your losing is weighing you down, stop and restrategize .
You are absolutely right op this is the major challenge that is making most gambler not be responsible in life more especially those people's that is always playing virtual they are the ones that is always making gambling to look some how you will see some of them will carry like 5k to go and play virtual maybe there luck shine they will won reach 50k instead of them to leaf the gambling shop they will said that they going to still won more bet before they would realize there self they have already exhausted the one that they have won.