i have recently talked to a fellow luthier who is specialized in acoustic guitar building. he told me that the 'correct' way of measuring a scale length is by measure from the nut to the 12th fret then doubling that distance to get the correct placement of your bridge. while i have always known and as i read in books and online literature that the scale length is measured from the nut to the bridge. which method do you guys use? or is it preferable to use my method in electric building because we have our moving saddles to compensate for any differences in scale lengths?