If I loose 10 time 1 Euro. And win 1 time 10 Eur. I am still loosing even though I have minized the losses. Even if there is no commision on Forex, I am still loosing time and my interest to trade.
Many books suggests that you only enter a trade where you win more than your risk. That is not a flawed rule as it is incomplete. It is also necessary to calculate the probability:
How many times do you win and how much? How many times do you loose and how much?
If I win 10 times 2 Euros. And loose 6 times 3 Eurs than I am in profit of 2 Euros on every 16 trades even tough my losses were greater than my wins.