Well the first thing I'd put is "do they agree with me?" and make it a million points .
I'm not exactly an expert debater, but I think these would do as a couple of categories
1. logical argument (does the person state logically every step of the logic that leads to the choice?)
2. factual backup (does the person give facts from credible sources, and connect them with their stance on the topic?)
3. Persuasiveness (does the person do a good job at tying everything together to make a sound, logical, argument that could convince someone that their stance is correct?)
These are a few that I could think of, and I'm sure there are many more. I have never done any real debate but would be interested in trying it out. Maybe I'm way off here, but they seem good to me.
"You know the world is going crazy when the best rapper is a white guy, the best golfer is a black guy, the tallest guy in the NBA is Chinese, the Swiss hold the America's Cup, France is accusing the U.S. of arrogance, Germany doesn't want to go to war, and the three most powerful men in America are named Bush, Dick, and Colon. Need I say more?" - Chris Rock