X3D Fritz - Kasparov,G (2830) [C66]
X3D Man-Machine World Championship
New York USA (Game 2), 13.11.2003
1.e4 e5 Classical defense from Kasparov, who usually always meets 1.e4 with ...c5, his beloved Sicilian Defense (1.e4 c5). 2.Nf3 Nc6 3.Bb5 The Ruy Lopez, or Spanish Game. One of the oldest known openings. 3...Nf6 (D1)
Kramnik used this move against an earlier version of Fritz last year. 4.d3 According to Alex Kure, the opening book expert for Team Fritz, they wanted to keep the queens on the board and not allow Kasparov to follow the main line of the Berlin that Kramnik used to draw easily against them in Bahrain game one.
[4.0-0 Nxe4 5.d4 Nd6 6.Bxc6 dxc6 7.dxe5 Nf5 8.Qxd8+ Kxd8
The main line of the Berlin Defense of the Ruy Lopez. This line has been popular off and on going back a century. It's latest resurrection was caused by world number two Vladimir Kramnik, who used it to great effect against Kasparov in their 2000 world title match. The mighty queens come off the board and the game moves in slow motion.
Kramnik wanted to prevent Kasparov from displaying his famed tactical prowess and the same strategy makes perfect sense against a calculating monster like X3D Fritz. Kramnik played the Berlin in his first match game against Fritz 8 a year ago and, as he often did against Kasparov in their 2000 match, drew convincingly:
9.Nc3 h6 10.b3 Ke8 11.Bb2 Be7 12.Rad1 a5 13.a4 h5 14.Ne2 Be6 15.c4 Rd8 16.h3 b6 17.Nfd4 Nxd4 18.Nxd4 c5 19.Nxe6 fxe6 20.Rxd8+ Kxd8 21.Bc1 Kc8 22.Rd1 Rd8 23.Rxd8+ Kxd8 24.g4 g6 25.h4 hxg4 26.Bg5 Bxg5 27.hxg5 Ke8 28.Kg2 1/2-1/2 Deep Fritz-Kramnik,V/Manama 2002]
4...d6 5.c3 Played to prepare the push d3-d4, taking over the center. X3D Fritz is still making moves from its opening library, also called its "opening book." This is a massive database with millions of positions take from previously played games and prior analysis. An opening book often takes up close to a gigabyte of hard drive space!
This opening book is how the X3D Fritz team tells their baby what to play in the first moves of the game, the opening phase. Before each game they try to predict was Kasparov will play. Then they look at the possible reactions that will lead to positions that X3D Fritz will play well when it leaves the book and has to think on its own.
There are so many millions of possibilities even in the first 10 moves of a chess game that this is far easier said than done. Even if you suspect what general direction your opponent is going to take, you can't prepare everything, there just isn't time. When human Grandmasters play one another they are both limited by their memories. No matter how much they prepare and study they have trouble bringing it all to the board with them come game time.
A computer player like X3D Fritz doesn't have this problem. Its memory is limitless and will store everything the programming team has time to enter into its opening book. It will play its moves instantaneously as long as it is still in a book position (as will humans!). One of the tricks Grandmasters use against chess computers is to play tricky move orders to get the machines out of their opening books as early as possible. The opening phase is very sophisticated and poor decisions made early will have repercussions ten, twenty, or even thirty moves later, far too deep for a computer to calculate.
The best opening moves have developed over decades and are based on Grandmaster experience and praxis. Computers don't usually do very well in this phase of the game on their own, the search tree of moves is too broad and the strategy too subtle. Therefore they use their opening books to reach playable positions, sometimes not "thinking" at all until move 20 or even later.
The debate about whether or not the use of these books is an unfair advantage for the computers has raged since the beginning. Kasparov put it back on the table after this painful loss, although he did quite well in the opening phase.
5...g6 6.0-0 Bg7 7.Nbd2 0-0 8.Re1 Both sides have made typical developing moves. Both kings have castled to safety and both sides put pressure on the critical central squares.
8...Re8 This move by Kasparov had never been played before in this exact position. It is hardly a shocking move and one that would likely be played soon regardless of the order. By playing it here Kasparov hopes (and succeeds) to get X3D Fritz out of its opening book. The machine is now calculating its moves on its own and still in a very early stage of the game.
9.d4 A Grandmaster likely would have waited a while to play this inevitable push in the center. White's pieces are a little tangled up. X3D Fritz sees no reason to delay; it wants central space. There is an immediate threat, the push d4-d5 attacking the c6 knight, which is now pinned by the bishop against the rook on e8.
9...Bd7 Breaking the pin, but guaranteeing that White can force the exchange of light-squared bishops. ..Nd7 was worth considering, but Kasparov doesn't mind exchanges that will decrease the computer's attacking potential. 10.d5 Ne7 11.Bxd7 (D2)