Does anyone here use Webmoney? Mr. Knight wants to be paid over that, but you need a cell phone to sign up. So it'd be nice if I can pay someone and he transfers it then.
We are in complete knowledge now of who is behind the pseudonym (and yes, it was one) of "Darius Knight". Sadly it was not the table tennis professional who seemed like an interesting personality from our short research.
Since the author has not wanted to put her or his name over the diagram, we respect the wish for anonymity and will not disclose this information. We can however say that it was not the same author as the mysterious "S.B. Preuss" on MatPlus magazine several years ago.