Oh I know that. Who is ranked where is not tennis knowledge. Knowing who has won what and knowing strengths and weaknesses of players is some tennis knowledge. But you last sentence is mostly what I'm referring to when I talk about Filo V and most of this forum. Filo V may know players' rankings but that's as far as it goes.
What is the difference between knowing who is ranked where and who has won what? Why is only the latter classed as tennis knowledge in your book? Being able to identify strengths and weaknesses of players can only really be quantified as about 5% tennis knowledge, or something, because any Tom, Dick or Harry could do that.
As I said, ATP tennis knowledge and knowledge of the sport itself are two entirely different things.