It will be no surprise to hear the best forex trading systems are the ones which make cash! The difficulty is simply the simplest way to identify which of them those are, and in particular, the simplest way to decide which system will work the best for an individual trader, i.e. You.
First let’s cross out some systems that never earn cash for anybody, at least not in the long term. These are the kind of systems that gamblers infrequently call loss recovery systems. The idea is that if your last trade lost, then your next is more likely to win, so you take a larger position. However this idea is completely wrong. Statistics disprove it every time. Gamblers lose their shirts on these systems and it’d be crazy for a foreign exchange trader to employ a system like that. To do that we’ll introduce the idea of edge.
Edge is the measure of a system’s returns over a period. It is a simple calculation but you do need a fair number of results to determine it from. Back testing is a good way to get those results. Demo testing is even better as it is closer to the genuine situation, however it can take a considerable time to collect enough results from demo testing so the general public use back tests which are quicker.