I think you need to control yourself in gambling and being discipline about your strategy, how you play and how well you calculated the winning odds could make your strategy works better, luck can't be rely on in gambling, you need to build strategy to win based on your experience, and strategy is only to help you prevent losing money not to add your winning percentage
It is very difficult to developed gambling strategies and even if one has a good strategy I will agree with you that " we should be discipline about our strategy", since we can not win all the time? The best way to handle things is to reduce your risk and gamble with carefulness!
Yes it is difficult to develop gambling strategies but there is a unique solution to that as well. In gambling, when you do not know and cannot figure out what to do, you should despite focus on what you do not have to do. This means that the odds of winning increases if you do not do something that could take you away from win at gambling. Experience speaks.