I couldn't agree more! Unfortunately, I'm just the converter, not the creator. If you foresee 14" BG in your immediate future, I would recommend the Wr chart found on page 32 of the July/August 2006 issue of Pondboss. This was part of a multi-issue big BG collaboration between Bruce Condello, Bill Cody, and Cecil Baird.
It only goes to 13", but perhaps you could extrapolate the data from that point forward....