I read this thread with some interest. Surely Captain Birdseye is aware that the way the string speaks depends on only two factors, bow speed and bow pressure. The length of the bow is always irrelevant. I have seen deafeningly strong performances given by a great fiddler using an 18th cent kit bow. I have heard weak performances given using a Toute style bow. It's all to do with technique. The Tourte style (modern) bow has two ends and so, if you develop the technique to use it, you have two 'power points' which give a more consistent tone. This, however, has little to do with 'fiddling'. In my opinion there is too much emphasis currently on 'folk fiddling' with a tonality more akin to classical playing. This is largely due to the numbers of 'converts' from classical violin styles. A careful study of traditional performers (and here I can only speak about European styles) reveals that, whilst tonality is considered, it is not the main emphasis of the player. In English traditional playing the accent is on rhythm, often to the total exclusion of tone. Bampton morris had a fiddler pre-Jinky Wells who used to emit a series of squeaks and grunts from his instrument which drove the dance beautifully but which sounded awful. I have seen Latvian and Hungarian fiddlers do much the same thing. Even players like Walter Bulwer and Harry Cox eshewed a quest for good tone in favour of a driving rhythm. The bow is, in such cases driven from the wrist using the weight of the hand.( Playing in a crowded pub crushes the elbow to the ribs and forces this 'flipper-like' action which sounds great. )
I can't help but agree with the writer who talked about Louis Armstrong, Django Rheinhardt etc. It's uniqueness that matters. So why do all young fiddlers sound the same? (My experience is based on considerable exposure to young Northern English players. I once asked a young player, "If I were arund that corner and heard you playing, how would I know it was you?" She couldn't answer. The decision making hand is that which holds the bow. That's where characterful playing is to be found. Incidentally, its worth listening to the string section of the Simon Bolivar Youth Orchestra. Their bows are all over the place, each player plays the way they feel the music. Its classical music played by some pretty good fiddlers and it sounds great. Why play folk as if it were classical?