2017
AL#132 p.62               
Mark French                                                                                           

▪ We think the old boys found the 1st fret position by dividing the string length by 18. Then they divided that by 18 to get the 2nd fret. Sounds like a job for that nerdy apprentice kid. But 18 is just an approximation of the “right” number; that is, the 12th fret won’t be right in the middle of the string. If you want to do it by hand, here’s some thoughts and numbers about what would be a better approximation, and how much better it would be.