I've been thinking lately that the "importance" of a win in a soccer match depends on how good the opponent is.
Let's take the spanish league for example. You have some elite teams like Barcelona FC, or Real Madrid FC who win most of the games and are in other words powerhouses. You also have some other teams which are good enough to stay on the league but they are not elite...
So i've been thinking if a normal mediocre team manages to score a win against an elite team like Barcelona FC or Real wouldn't it make sense to consider this win more important than a win against a weaker opponent?
So basically what i am asking can someone propose a grading system or something along those lines that would allow to quantify the importance of wins against opponents of different caliber?