ZAPPA – RYBKA Beta

15th IPCCC 2005 Round 4

Petrosjan variation E12

Topic: Positional pawn sacrifice

GM Piotr Bobras

1.d4 Zappa is playing on 128 processors (!?). Rybka on one. Both are 64-bits programs. 1...Nf6 2.Nf3 e6 3.c4 b6 4.a3

BLACK TO MOVE

Petrosjan`s idea, after which move Bb4 looks suspicious J From polish players this variation is played often by GM Krasenkow and GM Wojtaszek. 4...Bb7 5.Nc3 d5 6.c:d5 N:d5 7.Qc2 N:c3 8.b:c3 Be7 9.e4 0–0 10.Bd3 c5 11.0–0 Qc7

WHITE TO MOVE

The end of Rybka opening book. Black treats 12...c:d4 to exchange queens. Endgames of that type of pawn structure usually are more comfortable for black, because black has possibility of creating “outside passed pawn”. White passed pawn would be in the center and so be can easily stopped by black king. Hence white tries to avoid endgame and looks instead how to use its center to create attack on the king side. 12.Qe2 Nc6 13.Bb2

BLACK TO MOVE

13…Na5 [13...Rfd8 14.Rad1 Na5 15.Ne5 Bd6 16.f4 f6 17.Ng4 h5 18.N:f6+ g:f6 19.e5 c4 20.Bg6 Qg7 21.Q:h5 Bf8 22.e:f6 Qh6 23.Qg4 Kh8 24.Rde1 B:a3 25.Re3 1–0, Pedersen,Stef 2441 - Pelletier,Y 2589 , GER Bundesliga 2004-5] 14.e5?! Interesting is to play 14.Ne5!? and if 14...Bd6 15.f4 += Similar to the game Pederson-Pelletier. 14...c:d4 15.c:d4 Nb3! =+ Rybka plays like human! This move is a positional pawn sacrifice.

WHITE TO MOVE

16.B:h7+ K:h7 17.Qd3+ Kg8 18.Q:b3 Bd5 19.Qe3 Qb7 Lets evaluate position!

WHITE TO MOVE

Black has strong bishop pair, which will support black pawn advantage on the queenside, also black bishops basically will cancel any attempt of attack on little weak black king position. White has “dead body” on b2 square, weak white squares and ... a pawn more. Black chances look much better than whites especially if you consider that engine who plays with black "feel" inside this position like (little) fish in the water J 20.Rfc1 b5 21.Ne1 a5 22.f3 Rfc8 23.Nd3 b4 24.Nc5 Qb6 25.Rc2 b3 26.Rc3 Rc6 27.Rac1 Rac8 28.h3 Qb5 29.Kf2 a4 Black had created strong protected passed pawn on b3. Next 25 moves look like typical computer chess so, no comments J

WHITE TO MOVE

30.Qe2 Bh4+ 31.Kf1 Qb8 32.Kg1 Bg5 33.Rb1 Qb6 34.Bc1 Be7 35.Be3 Qa5 36.Rcc1 Bh4 37.Kh1 R6c7 38.Bd2 Qa7 39.Rc3 Be7 40.Be3 Rc6 41.Re1 Qa5 42.Rec1 Rb8 43.Qb2 Qb5 44.Kh2 Bd8 45.Bf4 Ba5 46.Re3 Bb6 47.Rec3 Rbc8 48.Be3 Bd8 49.R3c2 Kh7 50.Rd2 Kh8 51.Rdd1 Kg8 52.Re1 Qb8 53.Kh1 Be7 54.Rg1 Qb5 55.Rge1

BLACK TO MOVE

55…f6! Finally! I started to think that I am in danger to fall asleep J White has problems to keep its Knight on c5 spot. The move 56.f4?! even more would have weakened diagonal a8-h1. 56.e:f6 B:f6 57.Qd2 Bc4 58.Kh2

BLACK TO MOVE

58…R:c5! 59.d:c5 b2 60.Rb1 Rd8 61.Qf2 Bd3

BLACK TO MOVE

62.Bg5 Bd4 63.Be3 Be5+ 64.f4 B:b1 65.R:b1 Qd3 66.Qd2

BLACK TO MOVE

66…Bf6 67.Q:d3 R:d3 68.Bg1 Rd2 69.h4 Kf7 70.h5 Ke7 71.c6 Kd6 72.Ba7 K:c6 73.Bb8 Kd5 74.f5 e:f5 75.Bf4 Rd3 76.h6 g:h6 77.Bc1 Having lost position Zappa got crazy J 0–1, Zappa 2.1/3.0b x64 Remote - Rybka 1.0 Beta.