The good folks at the Swift Fly Fishing company, crafters of Epic rods, have penned a damned nifty essay on fly rods, detailing some things you probably don’t know, but should, in the fly rod world. Read Fly Fishing: Fly Rod Ratings, Fly Line Weights and the Arms Race here.
Well done. (This post was not solicited and is not an advertisement for Epic; I just happen to like it when folks decide to buck the mystique about things and tell the truth.)