Testing for sues
As most people are probably aware, the problem witht he term "Mary Sue" is that it's a non-term. A Mary Sue is whatever you want it to be, really. Any character can, and at some point probably has, been called a Mary Sue. The definition is not clearly defined, anywhere. Of course, there are obvious Mary Sues, like Naratu the Sky Ninja who is Naruto's long lost twin brother with purple hair and the spirit of a nineteen-tailed fo inside him. Who can fly.
But assigning numerical values to anything inbetween as belonging to a certain level of Sue-ness is very haphazard, and by its very nature inaccurate.
I took 3 tests. The first said my character was a solid 40, which is to say, a solid Sue. the second said he was a 23, or a Borderline Sue. The third had him at 80% Sue. This particular last test marked certain questions as "incorrect" if they were deemed Sue-ish. Such things included being attractive, having a sword, impressing peers, etc. Which is true! Those are things that can be considered common traits of a Sue. But they're also incredibly selective and short-sighted ways of determining if someone is a Sue.
The particular character I used is a big time criminal. He is the main character of his story, so he is also the protagonist. He is a bad good person. He breaks the law unapologetically and is ultimately unredeemable. So questions like "Does everyone know your character?", which may be reasonable for a 'good' protagonist, is basically meaningless as far as Sue levels are concerned with this guy. Other questions, like does he use a pseudonym, does he impress his peers, etc. Are also worthless because in his situation and story the answer just has to be yes. Similarly, questions like "Does he turn the villain good?" don't even make sense in context.
I guess what I'm trying to say is Mary Sue is a pretty dumb term to take seriously because every story will have to build its characters under completely different rules and in an unique universe. What would make a character a "Sue" in one story or situation would make it an okay one in another.