The early...c6 in a Queens Gambit gives us a Slav defense. This particular move order avoids the Winawawer counter gambit of the Slav which could arise by the "normal" move order of 1.d4, d4 2. c4 c6 3. Nc3 e5!? which produces very sharp play. It also avoids the main line of the Slav Defense after 3. Nc3, Nf6 4. Nf3, dxc4, in this last line black can also enter into the Semi-Slav with 4...e6 instead of 4...dxc4.
The Semi-Slav Defense. White is aiming for a slow expansion of his kingside and, after castling he plans to achieve a central plus with e3-e4.
Practically the only sensible move after which, depending on whites plan, black will develop his king bishop to either e7 ot d6.
This is one of the main lines. The major alternative is 6. Bd3.
With the text black plans a Queenside fianchetto. With the text black avoids the complexities of the Meran Variation which occurs after 6...cxd5 7. Bxc4, b5 8. Bd3. Black also can play 6...Bd6 or 6...Be7 here.
Black is solid. Now White retreats his knight to avoid swaps which would ease Black's cramp.
White intends the pawn advance d5
A very important move; black prepares to advance his queenside majority and at the same time stops the idea of Nb5 eg. 15. d6 Bxd6 16. Nb5.
A prophylactic move designed to kill your opponents counterplay before it becomes a problem. It would have been a mistake to play 15...Bd6 because after 16. Nf5! white would retain good play for the pawn as the knight on f5 would be a constant threat to the black kingside.
This is still book.
White should have played the almost automatic 17. a4 here to hold up the black queenside expansion.
Now we see why. Black queenside majority is mobile, while whites pawn on d5 is firmly blockaded. There is now good play for both sides.
Black gains space
Black has to be careful here. A greedy move such as 20...Nb6 would allow 21. Nf5! with a messy unclear position. Also worth of consideration is 20...Re5!? blunting whites play and intending to double rooks.
Black should not play 22...Bxd5 as 23.Rxd5 Eliminates the defender of d5 23...Nxd5 24.Bxe4 and white has an edge. Another alternative is 22...c4 23. Ne3 Rac8 which is playable for black.
This position appears roughly equal. Blacks Queenside majority is of no consequence but his overall development is active and harmonious. Whites d-pawn is securely blockaded and is under some pressure but not critical. The best thing to notice is that black has good attacking squares for his pieces and his main area of attention, the e-file, is unchallenged. With his next move black completes his development and is prepared for action on the kingside.
Not suspecting the danger. Cifuentes anticpates expelling the black knight from its outpost at e4 by the advance f3. The logical looking 24. Bf4 is suspect on account of the reply 24...Bf8 when 25...g5 is threatened. White should have played 24. Rac1! bringing his last piece into the game. CM 9000 after 30 minutes thought considers black a full point better and gives 24...Nxd5!? 25. Nc4, Qf5!? 26. Bxe4 Qxe4 27. Qxe4 Rxe4 28. Nxd6 Rxd6 29. Nf4 Nxf4 30. Bxf4 Rd5 31. Rfe1, Rd3 as best play, or also in this line 24...Bf8!? 25.Bxf8 Ng5 26.Bg2 Nh3+ 27.Bxh3 Qxh3 28.f3 Kxf8 29.Nb6 Rxe2 30.Qxe2 Nxb6 31.Rxc5 Qd7 32.Qe3 Qd2 33.Qe5 CM 9000 considers either of these good for black.
This move is made possible because the bishop retreat has loosened whites control of the g4 square. The white king will now be drawn out of his lair.
Annihilates a defender.
Perhaps hoping that black would accept a draw on move 29. The best defense is 26. Kxe3 Ng4+ 27. Kd2 Nxh6 28. Kc1 but after 28...Qe7! whites position is still full of holes and the a1 rook is still out of play and the king on c1 is awkwardly placed. Black would still retain excellent prospects.
Double attack. The point of blacks combination he exploits the g4 square.
The knight feels good on g4
Hoping for a repetition and a draw. I bet Roberto had missed Vadim's next bombshell as the mind often blocks out this kind of tactic. For the entire game the d5 pawn has controlled the e6 square, and then suddenly it is not due to the pin. --GM Hodgson
This increaces pressure on the e file and the a8-h1 diagnol and sets up a mating net.
After 30. Bc1 instead then 30...c4! 31. Bg5, Bc5 and black forces a quick mate.
Do you see the mate threat?
A spectacular Queen scarifice! Zviaginstev sacrificed first a knight, then a rook, and finally his queen to drive the king out into the open board. Truely a game worthy of comparisons to Anderssen's Immortal and Evergreen games.
34. Kh4 wasnt too promsing on account of 34...Be7#
It's all over
White Resigns. The threat of Bf8 or Rh5 mate can't be stopped.
This game was dubbed the "Pearl of Wijk aan Zee" by those participating in the tournament.
Tactical Themes: Demolition, Pin, Removing a Defender, Double Attack, Enticement
Mating Themes: Long Diagnol Mate, Bishop and Knight Mate, Linear Mate.
I consider this to be the 10th greatest attacking game of all time.