Originally posted by kNIGHTHEADYes, most people would guess the number at a couple of hundred thousand.
"Shannon number"
There are more chess games than atoms in the universe!
The number of possible chess games = 10^123
The number of atoms in the known universe = 10^80
http://en.wikipedia.org/wiki/Shannon_number
(at least the people I have asked)
It is amazing.