Shannon number

The Shannon number, named after Claude Shannon, is a conservative lower bound (not an estimate) of the game-tree complexity of chess of 10120, based on an average of about 103 possibilities of a move for White followed by one for Black and a typical game lasting about 40 such pairs of moves.

History

Shannon calculated it to demonstrate the impracticality of solving chess by brute force, in his 1950 paper "Programming a Computer for Playing Chess".

This influential paper introduced the field of computer chess.

See also

• Chess
• Claude Shannon
• Computer science
• Information theory

External links

• Shannon number @ Wikipedia