If you are only playing the major scale in one octave, then the notes of the scale are physically close together on the fretboard. Your hand doesn't have to travel far to get the next note. Extending the octave range, however, requires you to change your hand position. sometimes, especially with the flat keys, this jumping to a new position, or 'position shift', as Pat Cloud calls it in his book 'The Key to the 5-String Banjo', requires that you go from a fretted string, way up the neck to another fretted string, either on the same string or different one. While difficult to execute at first, it becomes easier with practice. (think of guitarists and mandolinists having to do that all the time). Once you have changed hand positions to extend your octave range of the scale, usually the new position will have a cluster of notes that can be reached without moving the hand much, like in the first position.

The reason you may play, say, the note 'C' on the 4th string, 10th fret as opposed to the 3rd string, 5th fret could be that you are in the middle of a 'position shift', or that your hand is already in a C major position near the 10th fret and it is desirable to get the 'C' there instead of falling all the way down the neck.

Hope this all makes sense! Scales really are just catalogs of notes. In my book, I stress knowing these notes for the whole range of your banjo fretboard. As a result, The fingerings are plotted out to allow the easiest way to navigate that distance. If you check out Pete Pardee's "Scales and Arpeggios for the 5-String Banjo" (and everyone should have that great book) he lists many different ways to play each scale. Some seem ridiculously hard to me, and others seem easier than I'd have figured out myself. It all depends on the what's the best way for *you*, at any given moment.

Thanks to David Crisler.