Just read an excellent book on history of wet flies in the Yorkshire Dales by Leslie Magee. Many interesting things, but the book said that the top fishermen and river keepers (guys that caught 2000 fish a year) used only a single fly and secretly looked down on the city folk relying on mulitple flies. The argument was that one did best by selecting a fly by careful observation of the water, fish, bugs, and birds and working it hard rather than just putting on a bunch of flies based on some standard chart and hoping for the best. Seems pretty sound to me.

The other interesting comment was that prior to stocking the fishing was for plenty of small, wild browns about 7" long and weighing three to the pound and that a 1 lbs fish was a fish of note. The introduction of stocking is what put the 1 lbs to 3 lbs fish in, and these fish were not as free rising to little bugs as the small wild ones.