Getting the best median parses

So let’s say that nobody you raid with ever logs.
You’re the only one, and upload each boss kill in a separate report.
Then you delete all the reports you did really bad in, wouldn’t this give you the best median parses on your profile?

Sure, but the odds that you’re the only one logging are extremely low (that would never happen on Mythic for example), unless you’re talking about Normal/Heroic content, and people don’t pay much of any attention to median scores for easy difficulties.