is fly pattern important?

[jross]

I've been thinking about this.... I got a lot of replies to my "spring flies" question... Some people like type A, others don't use type A but like fly B...So does type of fly matter that much? Or is it more about technique/skill of the fisherman? Won't these fish pretty much eat anything that looks like a bug if it gets near?....(just an observation in the form of questions? )