Some numbers..... (Score 4)

According to the Oxford Companion to Chess by David Hooper & Kenneth Whyld, the number of legal board positions is about 2 * 10E43.

In a game limited games to 50 moves, with a very modest average branching factor of 15 moves per ply. Exhaustive analysis of this limited tree would require enumerating 10^120 nodes.

One widely accepted estimate for the number of atoms in the observable universe is 10^80. If each such atom were a supercomputer capable of generating and evaluating 1 trillion board positions per second, and had been doing so since the Big Bang (say 20 billion years ago), only the tiniest fraction of the analysis would thus far have been completed.