Disliked........No one to this point has discussed the number one reason why the odds are not in your favor. The number one reason should be leverage!......Ignored
Leverage has nothing to do with either expectancy or risk:
-- Risk is the percentage of your account that you're willing to lose on a trade.
-- Leverage determines the amount of money you need in your account ("margin") to be able to take the trade.
See my post here for details: http://www.forexfactory.com/showthread.php?p=1582995
In my experience, timing entries and exits accurately enough, often enough to attain profit regularly, is the most difficult part. Expectancy is the product of your entries and exits, and operates completely independently of both position size (MM), and leverage.
David