1.Nf3 Kasparov almost always opens with 1.e4 these days, at least against humans. But over the course of his 25 year professional career he has played just about everything.

1...d5 2.c4 c6 3.d4 Nf6 4.Nc3 e6 (D1) Logical and normal development into what is called the Slav Defense. This is a well-known system that is particularly well-known to... Garry Kasparov! The X3D Fritz team shows no fear and heads right into Kasparov's strength.

They wanted to show they didn't fear his preparation. This choice is also relevant because in Kasparov's last computer match, against Deep Junior in January '03, he crushed the machine in this exact opening in the first game!

5.e3 Nbd7 6.Qc2 Bd6 [6...b6 7.cxd5 exd5 8.Bd3 Be7 9.Bd2 0-0 10.g4 Nxg4 11.Rg1 Ndf6 0-1 Kasparov,G-DEEP JUNIOR/New York USA 2003/(36)]

7.g4 A very aggressive move that offers a pawn in exchange for attacking chances. If Black captures the pawn with ..Nxg5 White gets a lot of pressure on the open g-file. Kasparov has played this position three times, twice with white and once with black! He won all three games, including one against the computer program Deep Junior earlier this year.

7...Bb4 A normal move still in the "book" of both players. X3D Fritz has almost three million positions in its library of opening moves and sequences. Kasparov is legendary for his opening preparation and knowledge. He is a walking encyclopedia of opening theory and his opponents have a healthy fear of his surprises in the openings.

This move also takes the game away from the game Kasparov won against Deep Junior in this line. That's a sort of psychological advantage, being the first to spring something unexpected. Between two humans it could also be sort of like a game of chicken, with the first player to turn off from the previous game being the chicken. No matter how well it plays chess, this aspect is lost on X3D Fritz. It is not, however, lost on its creators and operators!

[7...dxc4 8.Bxc4 a) 8.g5 Nd5 9.Bxc4 Nxc3 10.bxc3 e5; b) 8.e4 e5! 9.g5 0-1 Adams,M-Kasparov,G/Dortmund 1992/CBM 29/22) (b) 9.dxe5 Nxe5 10.Nxe5 Bxe5 11.g5 Nh5) ; c) 8.g5 Nd5 9.Bxc4 Nxc3 10.bxc3 e5; d) 8.Bxc4 Anand; 8...b6 9.e4 e5 10.g5 Nh5 11.Be3 0-0 12.0-0-0 Qc7 13.d5 b5 14.dxc6 bxc4 15.Nb5 Qxc6 16.Nxd6 Bb7 17.Qc3 Rae8 18.Nxe8 Rxe8 19.Rhe1 Qb5 20.Nd2 Rc8 21.Kb1 Nf8 22.Ka1 Ng6 23.Rc1 Ba6 24.b3 cxb3 25.Qxb3 Ra8 26.Qxb5 Bxb5 27.Rc7 1-0 Kasparov,G-DEEP JUNIOR/New York USA 2003/ (27); 7...0-0 8.g5 Nh5 9.Bd2 f5 10.gxf6 Nhxf6 11.Ng5 Qe8 12.0-0-0 h6 13.h4 Shirov,A-Thorhallson,T/Reykjavik/1992/]

8.Bd2 Qe7 9.Rg1 Bxc3 10.Bxc3 Ne4 11.0-0-0 (D2) A new move instead of the usual 11.Bd3.

[11.Bd3 Nxc3 12.Qxc3 0-0 13.0-0-0 dxc4 14.Bxc4 c5 (14...b5 15.Bd3 Bb7 16.Ne5 Nxe5 17.dxe5 Rfd8 18.Kb1 a6 19.Qc2 1-0 Malakhov,V-Potkin,V/Togliatti RUS 2003/The Week in Chess (39)) 15.g5 cxd4 16.Qxd4 a6 17.Kb1 b5 18.Be2 0-1 Milanovic,D-Djerfi,K/Belgrade 2003/CBM 96 ext (33)]
 

11...Qf6!? Now that we are out of X3D Fritz's opening library of recorded moves it is thinking, calculating, for itself. And right away we see a very "computer-like" move from the computer. It immediately plays to win a pawn by attacking the unprotected knight on f3.

12.Be2 Kasparov protects his knight and offers the f2 pawn for capture.

12...Nxf2 And X3D Fritz takes the pawn! This will give White a lot of pressure against the black position in compensation for the sacrificed pawn. It's ironic that we have the strongest chess computer of all time here and it is playing in the materialistic mode of the first chess programs. In X3D Fritz's opinion, it has enough defensive resources to rebuff Kasparov's initiative.

This battle of material vs initiative is what chess is all about. Kasparov gives up a pawn for an attack, but if his attack doesn't succeed then X3D Fritz will have good chances to win with the extra material. Kasparov loves to have the initiative and such sacrifices are his stock and trade.

13.Rdf1 Attacking the black knight. 13...Ne4 Retreating the knight. One of the drawbacks of X3D Fritz's pawn grab is that now the f-file is open for White's pieces. Right now Kasparov is threatening a discovered attack on the black queen. That means when he moves his knight, there will be a line of attack opened for his rook. 14.Bb4 (D3) Kasparov moves his bishop away so the knight can't capture it. He uses it to prevent the black king from castling by attacking the f8 square.

[14.Ne5 This is the discovered attack. Note that now Black's queen is under fire from the rook on f1. When the queen moves Kasparov would be able to capture the pawn on f7. But X3D Fritz saw well in advance that its queen would be able to counterattack effectively. It's hard to fool a computer looking at four million moves per second. 14...Qh4 15.Nxf7 0-0! Creating a double attack on the f7 knight. 16.Ne5 Rxf1+ 17.Rxf1 Nxe5 18.dxe5 Qxh2 Black maintains its extra pawn and has a clear advantage.]
 

14...c5 This move apparently came as a surprise to Kasparov, who now went into a deep think after playing all of his previous moves at tremendous speed. X3D Fritz gives back the pawn in order to block the white bishop's diagonal and open lines toward the White king.

15.cxd5 exd5 16.dxc5 Qe7 Getting the queen away from the discovered attack on the f-file and also attacking the c5 pawn. Material is now equal, Kasparov has an edge in development and X3D Fritz has a very well-placed knight on e4.

17.Nd4 A typically dynamic Kasparov move. He will play his knight to the aggressive f5 square. He ignores the threat to the c5 pawn since capturing it would cost Black a great deal of time.

17...0-0 Getting the king to safety, but allowing Kasparov to play a powerful sequence of moves here that will win a rook for a bishop and pawns. A rather surprising decision from a program that has already shown itself to be a bit of a materialist! [17...Ndxc5? 18.Bb5+ Kf8 Now the black king is stuck in the middle of the board.]

18.Nf5 Attacking the queen. 18...Qe5 19.c6 Kasparov goes for it. This pawn push is a discovered attack. The pawn attacks the knight and at the same time the diagonal for the b4 bishop is opened up to attack the rook on f8. He is going to win a rook for his bishop, a gain in material, but he usually likes to be the one giving up the material for the attack. Now X3D Fritz will have the initiative and more active pieces. 19...bxc6 20.Bxf8 (D4)
 

The logical continuation, although he could also have checked the black king and infiltrated with his knight with 20.Ne7+.

20...Kxf8 Our Grandmaster commentators were expecting X3D Fritz to recapture with the knight instead of moving his king into the middle of the board. The machine prefers to keep its pieces more active and isn't worried about its king at all.

A human would instinctively worry about putting his king out into traffic. A computer just looks at a few hundred million positions, sees no danger, and plays what it thinks is best.

[20...Nxf8 21.Bd3 (21.Qxc6? Rb8 With great attacking chances for Black.) ]

21.Ng3 Kasparov wants to trade material. He has a material advantage and every exchange will bring him closer to realizing it. 21...Ndc5 22.Nxe4 Nxe4 23.Bd3 Threatening yet more trades.

23...Be6 Finally developing this bishop and preparing to lodge it on the d5 square after Kasparov captures on e4. The bishop also protects the f7 square on the vulnerable f-file. Computers always defend tenaciously. 24.Bxe4 dxe4 Kasparov's mission to exchange pieces has been successful, but how to now convert his slight material advantage into a win?

25.Rf4 Bd5 Protecting the attacked e4 pawn. Black has set up a solid defensive wall and it's up to Kasparov to find a way through. 26.Qc5+ Activating the queen with check, forcing the black king back. This move also pins the bishop against the queen.

[26.Qc3 Many expected this move, offering to exchange the queens and driving the black queen from her excellent central post. X3D Fritz definitely wouldn't exchange queens because then Kasparov's material advantage would be close to crushing. X3D Fritz needs the powerful queen on the board to keep counterchances. 26...Qd6]

26...Kg8 27.Rgf1 (D5)
 

Threatening the brutally blunt capture Rxf7, taking advantage of the pin on the bishop. This move was criticized by several of the assembled Grandmasters as "too subtle." Black's reaction develops a piece and White's threat is easily parried. The more direct 27.Rd1 was more to the point.

27...Rb8 Answering Kasparov's threat with an even stronger one. X3D Fritz threatens a lethal capture on b2. 28.R1f2 Protecting b2 and so reviving the threat to capture on f7.

28...Qc7 Removing the pin on the bishop and so threatening to capture the unprotected a2 pawn.

29.Rc2 Kasparov prefers to answer a threat with a counter-threat instead of playing defense. Now if Black plays ..Rb5 Kasparov exploits the new pin on the c-pawn and captures the rook with Qxb5. [29.Kb1 Protecting the a2 pawn with the king.]

29...Qd7 [29...Bxa2 Grabbing the pawn immediately was playable, but now White's rooks get a lot of play.; 29...Rb5?? 30.Qxb5!] 30.h4 Another aggressive surprise from Kasparov. Just when all the action was on the queenside and in the center, he threatens to open a new front by pushing his kingside pawns against the black king. 30...Qd8 31.g5?! (D6)
 

This move made X3D Fritz very happy, at least according to its evaluation function. It now considers it safe to capture the hanging pawn on a2. Kasparov wants to play h5 without allowing Black to block his pawns with ..h6. But this plan is just to slow and now X3D Fritz grabs a pawn on a2.

[31.h5 This push instead of g5 wouldn't have given X3D Fritz time to capture on a2 because of the threat of h6. 31...Bxa2? (31...h6) 32.h6]

31...Bxa2! A surprise for Kasparov. Perhaps that pawn had sat there immune for so long that Kasparov started to believe it couldn't be captured! Not only does Black win a pawn but suddenly White's king is feeling a draft.

32.Rxe4 Almost a draw offer since it is now very hard for White to find any move to avoid the repetition that does indeed end the game. [32.Rd2 This move was expected by most commentators. It pushes the black queen off the d-file and claims it for White. Then Kasparov could continue his kingside push. 32...Qe8 33.h5] 32...Qd3 (D7)
 

Bringing the queen to a dominating position and creating threats around the white king. 33.Rd4 Giving up another pawn in order to remove the worst of the black threats.

33...Qxe3+ X3D Fritz alarmed the commentators by spending eight minutes on this obvious and forced move. Seirawan, Ashley, and Hoffman wondered if there was a malfunction!

Nothing of the sort. X3D Fritz had plenty of extra time, so it was in no hurry. It had started to see the repetition draw that now comes and when a decisive result comes into its analysis horizon the program gives itself more time.

34.Rcd2 The only move.

[34.Rdd2?? Rxb2! Whoops, giving up the queen but getting checkmate in return! A fine illustration of the dangers around White's king. 35.Qxe3 (35.Rxb2 Qxc5+; 35.Kxb2 Qb3+ 36.Ka1 Qb1#) 35...Rb1# Checkmate!; 34.Kd1?? Re8]

34...Qe1+ Black is in considerable danger as well. Not only does Kasparov have a material advantage, but the black king is not safe. 35.Rd1 The only move. The open white king, hemmed in by the bishop on a2, is too vulnerable. [35.Kc2?? Bb1+ 36.Kc3 Qc1+ 37.Rc2 Qxc2#]

35...Qe3+ The first repetition of the position. If the same position is about to appear on the board for the third time, the player can claim a draw by repetition. We call the version here a "perpetual check."

36.R1d2 The other moves are suicidal. Kasparov has no choice but to accept the perpetual check draw if X3D Fritz wants it. [36.Kc2?? Qb3+ 37.Kd2 Qxb2+; 36.R4d2?? Qxc5+]

36...Qg1+ This was the last fork in the road. X3D Fritz could have continued the game with ..Re8. The machine decides that there is no way to play for a win and forces the repetition draw. [36...Re8 Black can keep the game going this way, but it was very risky and without any advantage. 37.Qc3; 36...Qe8? 37.Rd7] 37.Rd1 1/2-1/2 (D8)
 

Now the draw is completely forced because the black queen has no alternative to checking on e3 again and creating a third repetition.

Any other move loses immediately. White is threatening to win instantly with Rd8+. So going to g1 for check instead of back to e1 was just a show of computer humor, if you will! The result is the same: draw.

A rich and exciting battle with chances on both sides and unexpected play from the beginning.

You can replay this game online with all the notes here.