Been working through the 3 string slide course, learning a lot and having fun. I currently own a 3 string license plate CBG. However I had a 4 string standard CBG made and should be arriving soon. I am looking forward to starting the 4 string fretted course. The 4 string will be more for chord and fretted playing, where the 3 string is more for blues and slide playing. I was curious on the most common tuning of the 4 string, G D g b. So in open tuning you have the root, fifth, octave, third (of the octave). Why is the third placed as the third of the octave? Logically I would have thought root, third, fifth, octave in that order would be more desirable. I am versed in basic music theory and can play several instruments, however I am new to the guitar so I suspect that there is rationale for this (perhaps for chord layout?). Would you happen to know?