What is the total number of chess games that exist?

planet yahoo answers asked: Every chess game played is a unique game that already pre-exists in the book of all possible chess games. A chess board has 64 squares and 16 pieces per side. Out of which 8 are pawns, 2 rooks, 2 knights, 2 bishops, king and queen. What are the total number of [...]

What is the best chess tactics book and why?

Christopher Adams asked: I am looking to teach someone how to play chess. Having shown them the moves and one or two strategically ‘basics’ such as moving the pawns in the middle first, I am looking to sharpen their tactical ability so that they can spot things such as forks and skewers and win material. [...]