The Grunfeld is an exciting and dynamic answer to 1 d4, and has become very popular at all levels of chess. It relies on the principles of the hypermodern school of chess: Black allows White to erect an impressive-looking centre on the assumption that in the long run it could prove to be more of a liability than an asset. Play often becomes extremely complex and tactical, and this is clearly one of the reasons why the Grunfeld appeals to ambitious players. It has been a long-time favourite of arguably the World's strongest-ever chess player, Gary Kasparov, who utilized it many times in his numerous World Championship battles.