Lol. The thing is, Casparov came on here asserting (wrongly) that atheists are materialists, period. If anything I think "free thinker" is a better definition. I understand the possibility of things as yet identified, and the possibility of alternate universes and so on. What he basically did was put us in the position of defending materialism; I don't actually think of myself as one, I just go on what the evidence says.
There are so many different theories out there, from holographic universes to string theory and so on that have yet to be proven, that numbnuts can claim anything. But what he hasn't understood is that evidence has to be concrete enough and understood by the majority to be agreed upon. Silly man.