Whenever i pvp on arch duels are anywhere in arch my hits register 50% of the hits and i can NOT win any games like this

prob. just your ping, or your lag. 
1. decrease render distance

2. turn particles to minimal

3. turn entity shadows to off

4. make sure you do not have any fancy graphics (ex: fancy graphics, smooth lighting, SHADERS, ect)

that should make your fps higher. For your ping, try getting closer to your internet router, or to a place where you would get better wifi. Hope that helps!