Ok, I think you need to think of trading like gambling. Ever heard of professional gamblers? They're basically in the same game as professional traders: they both work out a *statistical* edge with which to win in the long run. To concentrate on trading: say you fix a limit at three times your stop loss (at a level you have backtested to work according to various scenarios - fibonacci retracements are a common tool for example), if the probability of you being right on any trade is 50% (the same as flipping a coin), you will get the edge over time.