The distiller's contribution to the flavour of the whisky is certainly less than 100 per cent. But is it fifty per cent? No. Twenty-five per cent? No. Could it be 5 per cent?
The Fractionating Flavour graphic opposite does not clearly show the overwhelming influence of the wood on the whisky. Because it splits the wood's influence into two parts: the wood itself and the other flavours (eg fortified wine) introduced into the wood by previous use of the barrel. This distinction is itself rarely made and I could not find any quantification of the relative significance of the two on taste.
Naturally, the distiller wants to believe that their role is highly significant, but the distiller's influence is found within the component "Copper"—and even there it is a combination of the material of the still and its shape and the distiller's management of distilling. The distiller's contribution to the distillate is a very small fraction indeed, hence my distinction between distiller and whisky-maker.
The power of the whisky-maker to determine grain selection, malting, brewing and distilling makes their significance dramatically higher.