(Okay, think this is the right board for this.)
Basically, if you lose a lot against above average players, but can beat people who aren't as good, are you just average?
Is there a way to tell if you're below average, average, or above average?
You need to play quote an awful lot of people from different regions and frequently against the same people to really get a good grasp on that. Otherwise, you will always be isolated to whatever sample size you get around you. For example, where I stay for school, I am the best brawl player. However, this is only because my scope is like 4-5 people. Once you include the occasional tournament that ran brawl, I placed better than anyone who was relatively new, but worse than those who were seasoned.
However, its hard to tell at tournaments as well since some people might show up which are just a clear cut above the rest of those available. It would be sort of like if you saw M2K pop up at a small best buy tourney playing people who have very little experience. M2K is the best there, but you really have no idea to know how much better he was until you see him play other people, then see how those people play.
Again, you really will find it difficult to gauge your prowess against say the entirety of everyone who plays smash. However, you can still get an idea of how well you do compared to those you play with often. Once you start to expand to playing other people it gets easier to see.