JC once wrote an article (I think) about giving the fish the butt. Imagine for a minute a 100 lb fish pulling on your line and you with a 1 wt. If your rod is straight out, the fish can't damage your rod. The more you bring your rod perpendicular to the pull of the fish the more you put a bend in it to the point that the 100 lb fish could break your 1 wt rod. Mostly, you tire the fish with your drag and use the rod to recover line. By using more of the butt of the rod and less of the tip you are able to use lighter rods to handle bigger fish. If you go too light you do have difficulty managing the fish and bringing it in but using the butt gives you more ability to handle a larger fish.

PS If going after 100 lb fish I reccomend at least a 2 wt.

jed