Hey Pierre ,

Interesting question and conception about the chin rest and weather to regulate the type used or not ....without causing too much of a stir among the google experts , I'll just state that yer perception of the chin rest ability to change or alter tone is both true and false ...once again , as with sooo many aspects  of violin building and design , it really does vary from one instrument to another from making a big difference in some violins to no decernable difference in others ...

There are really big differences of opinion on this subject and i'm sure we'll be hearing more about it sooner than latter ....

Factors to consider include but are not limited to weather , as an organization , would the VMAAI even wish to put such constraints on makers ? In as much as the chin rest selection may or may not enhance / inhibit tone in any one particular violin there even seems to be contention on clamping location vs mas / material used ..

To complicate matters even more is , is the relationship between chin rest , tail piece design and material and shoulder rest type combining together for tone production ..

How many folks just blow off the use of progressive tail pieces fer instance , something i personally favor on some but not all violins ...

It's important to remember that the judging is done by playing judges as well as listening judges and then averaged the score ...a particular chin rest on a Strad model may put the players ear in a position somewhat different than say another model with somewhat different F holes , resulting in tonal perception of the playing judge to vary , thus affecting the score .

I might add that the judges are all professional players but not nessecarily builders ..

Many builders do try out a number of chin rests types to determine if one is better than another on their pride and joy of the year .

I like the idea of clamping on the end block fer structual reasons but often miss the nice resonance the tail piece can give under my ear but not noticeable to listeners at a distance ..

Variances in diaphramatic responce from one violin to another vs the players ability to recognize and exploit these differences by use of the players testing has brought about a very standardized test procedure to eliminate the playing judge being able to influence the results ....fortuneately ....

I don't expect some to agree with my take on these things entirely , but you can see where i'm coming from maybe ..

As always , thanks fer yer interest and input Pierre ...

The winner of this years violin tone award is a student of a well known local builder's school of violin making ...I am always impressed when a student out does the resident masters ...last year a young lady won best cello tone with her first build as well ....