This is completely out of this world- and dates back 50+ years. From Wikipedia:
The Shannon number, named after Claude Shannon, is an estimated lower bound on the game-tree complexity of chess. Shannon calculated it as an aside in his 1950 paper "Programming a Computer for Playing Chess".How complex is chess? What are the number of possible variations, iterations and whatever -ations you can think of? Back to Wikipedia. Shannon calculated that:
there will be 10120 (10 to the 120th power) variations to be calculated from the initial position. ... Victor Allis extimated it as 10123(10 to the 123rd power).In case you don't understand the incredible size of that number, the number of atoms in the observable universe is estimated at (only) between 4×1079 and 1081
Staggering. No wonder I had such a hard time winning.