| The bridges on violin family instruments are, from an engineering viewpoint, up againts two limits; mass and flexibility. Both these qualities absorb sound, starting with the highest frequencies first. If the bridge is too heavy, it will not move in response to high frequencies, which have less energy than low ones. If it is a bit too flexible, the movement will absorb highs, but still effectively transfer lower frequencies. When you're shaping a bridge 'by ear', it will sound better and better as you remove wood, up to a point. This is because you're removing mass. When you reach the point where the bridge begins to get flexible enough to absorb the highest frequencies produced by the fiddle, an audible 'roll off' of the highs will begin to be heard.
All this can be inferred by looking at the basic construction of a violin family bridge. What look like decorative holes actually make the bridge into a structurally solid 'X' shape which is both as stiff and as light as it can possibly be. Also, the practice of exactly quarter sawing the wood ensures that the bridge is as stiff as it can be. Furthermore, one side of the bridge is more exactly quarter sawn than the other, which means that side aims directly towards the center of the tree. That side is stiffer than the other, and is traditionally faced towards the tailpiece to best resist the bending forces of the strings. If highest stiffness to weight ratio were not the deciding factor of bridge design, almost any design would work. But, hundreds of years of empirical development have arrived at a very narrow, and specific design that meets the requirements. | 
