My debate advice: Don't look at it from the point of view of "I'm right, you're wrong, and I'm going to prove it to you". Develop your opinion and idea, present it, and counter-attack the opposite side. If you keep your idea that what you think MUST be right, and they MUST be wrong, then you have the potential in limiting yourself to the full expanse of your argument. Let their idea feed yours. The best mind is a flexible one. That doesn't mean you will be less strong, but it does give you the ability to move at a pace faster than your opponent's.