Book excerpt: In February 1996, a chess-playing computer known as Deep Blue made history by defeating the reigning world chess champion, Gary Kasparov, in a game played under match conditions. Kasparov went on to win the six-game match 4-2 and at the end of the match announced that he believed that chess computing had come of age. This book provides an enthralling account of the match and of the story that lies behind it: the evolution of chess-playing computers and the development of Deep Blue. The story of chess-playing computers goes back a long way and the author provides a whistlestop tour of the highlights of this history. As the development comes to its culmination in Philadelphia, we meet the Deep Blue team, Garry Kasparov and each of the historic six games is provided in full with a detailed commentary. Chess grandmaster Yasser Seirawan provided a lively commentary throughout the match and here provides a Foreword about the significance of this event.