After you have won for some time and have a nice profit there comes a time when you start losing and that is where you are the most vulnerable and should stop betting for a while until you are not emotional anymore. The reason is you get upset for losing some of your profit, then you start reasoning that you can make up the loss and still have the same profit. You think that since you are losing profits its ok to keep going b/c you are not playing with the money you started but with the profit. Then you start making aggressive bets that you wouldn't have made with the money before the profit. If you end up losing those aggressive bets you get angry and increase the bet amount again something you wouldn't have done before..Then before you realize it you lose your whole profit and then that makes you even more upset and vulnerable, and you say to yourself oh well it's my play money I don't mind losing it I made a profit before and you keep betting and lose that too. What I used to do is after I make a profit, once I start losing I stop for a week then come back if i Keep losing stop for another week and it helped me maintain my cool. There have been times where with the losses I have been at a plus for months, and then I have had more losing than winning for months, but I have always taken a break between the losses and has helped me keep my cool and not get emotional.