I recently watched William Lane Craig's debates with Christopher Hitchens and Sam Harris and in both debates, it was easy to walk away with the feeling that Craig won. Hitchens just kept saying "I haven't heard any convincing evidence..." Without refuting Craig's arguments. Sam Harris did something similar - instead of addressing Craig's arguments, he ignored them for the entire debate. Also, Lawrence Krauss, when debating Craig about A Universe from Nothing, missed an opportunity to counter Craig's (correct) assertion that the primordial soup of the universe is not nothing.
Now, I've heard refutations for Craig's arguments but neither Hitchens, Harris, nor Krauss used them and so it could seem as though they lost their debates with him. Craig even invited Hitchens to become a Christian while onstage, and was justified in asking - given their performances in the debate. Any ideas why they froze up in their debates against him?
I also noticed that Craig got first word in those debates, in which he was able to define the terms used in the debate, giving him an edge.