Why should you talk about losses if set a proper SL?
A small tip:
You can look at it very simple. A trade will either move in your favour or the oposite direction. You have roughly 50% chance. If you do some analysis, at some points (for example at a resistance/suppor), you have a higher possibility of some direction. After a confirmation, you have even higher possibility of some direction.
Some expected/unexpected news (example Trump) can invalidate all your analysis. But you still have 50% chance.