Grandmaster games are said to begin with novelty, which is the first move of the game that exits the book. It could be the fifth, it could be the thirty-fifth. We think about a chess game as beginning with move one and ending with checkmate. But this is not the case. The games begins when it gets out of book, and it end when it goes into book..And this is why Game 6 [between Garry Kasparov and Deep Blue] didn't count...Tripping and falling into a well on your way to the field of battle is not the same thing as dying in it...Deep Blue is only itself out of book; prior to that it is nothing. Just the ghosts of the game itself.