Sorry, I didn't answer why? Well, why not? It depends on the water really Andy, but normally with me its a case of trial and error. If I don't know a particular water, I'll usually ask if possible what works, etc, and try different baits on different sessions, or try a different one on each rod till i find out for myself. Whatever works, I stick with it, until I catch no more, and try something else, and so on. I cannot give a more specific reason thatn that, I'm afraid, but then I'm still a beginner really! Some of these boys on here will able to give you more specific reasons I'm sure??? And you might help me a bit too?