Is it any wonder so many fail at this endeavor when the instinct of the many seems to be to ignore shared language and the meaning of words (acting as though words have no meaning other than what any individual chooses to attribute to them) and then furthermore to ignore the existence of the branch of mathematics known as probability and statistics?
If one knows the definition of "edge," then one should be able to identify whether he or she has an approach or method that provides an edge. If, on the other hand, one simply wanders around wondering "is this an edge? Is that an edge?" then one will ... simply continue to wander and wonder.