- 64. It's an 8 by 8 grid.

- Well... but don't you see how limited that is?

- No, it's actually very complex once you start to think about it as a programming problem. Just the number of possible games explodes exponentially with each move, it's close to 10 to the 120th power. And to try and compute all those games might take even longer than humanity would be around to do so.

in Computer Chess, 2013