IKARUS – RYBKA Beta

15th IPCCC 2005 round 7

Scandinavian Defense B00

Topic: Numbers and weight of positional mistakes

GM Wlodzimierz Schmidt

1.e4 Nc6?! It is hard to understand why Rybka plays such a suspicious move when having a choice of much better ones. 2.d4 d5 3.e5 Interesting was to play here 3.exd5!? 3...Qxd5 4.Nf3 Bg4 5.Be2 0–0–0 6.Be3 this variation in Scandinavian defense is quite complicated but it leads to adventure for white. 3...Bf5 4.Nf3 e6 5.Bd3 Nge7 6.Bg5 Be4 7.c3

BLACK TO MOVE

7…h6?! Positional pawn sacrifice for I guess not full compensation. This sacrifice makes game more dynamic. Better was probably 7...Bxd3 8.Qxd3 h6. 8.Bxe7 Bxe7 9.Bxe4 dxe4 10.Nfd2 Qd7 11.Nxe4 0–0–0 12.Qe2

BLACK TO MOVE

12…f6 13.f4 After that only seemingly good move black got strong initiative for a sacrificed pawn. Better was 13.exf6!? gxf6 14.Nbd2 'with the idea' 0–0–0. 13...f5!? 14.Nf2 g5! 15.0–0 Rhg8 16.Kh1This move was inessential, it was better to play immediately 16.Nd2

BLACK TO MOVE

16...g4 Strategical mistake. Black should keep a possibility to play g:f4 17.Nd1 h5 18.Nd2 h4 19.Ne3

BLACK TO MOVE

19…h3?! Like the first one, this sacrifice is too optimistic one. 20.gxh3 gxh3 21.Rf3 Rh8 22.Qf1 Perhaps better was 22.Rg1 first. 22...Bf8 23.Rxh3 Bh6 24.Qf3 Ne7 25.Rg1

BLACK TO MOVE

Black does not have compensation for 2 pawns. First pawn was sacrificed, second was lost due to an earlier mistake –16...g4? 25...Kb8 26.Rg2 Qa4

WHITE TO MOVE

27.Rh5? Unnecessary rush. Better was simple 27.a3 27...Qxa2 28.Qh3 Ng8 29.Ndf1 c6 30.Rg6 Re8 31.Rgxh6 Nxh6 32.Rxh6 Rhg8

WHITE TO MOVE

As a result of not accurate white moves, black got conterplay. 33.Qh5 Qxb2 34.Qf7 Qxc3 35.Rxe6 Ref8 36.Qe7 Qxd4 37.Qd6+ Qxd6 38.Rxd6

BLACK TO MOVE

After many ups and downs in this game arisen complicated, and hard to value and even harder to play endgame. Black indisputable priority will be to exchange rooks, because then black pawns on the queen side will become stronger. 38...a5 39.Ng3? A serious strategical mistake. White had to play 39. Rd2! Rd8 40.Re2 to keep a rook, which could stop for some time black "a" and "b" pawns.

BLACK TO MOVE

39...Rd8! Rook exchange is for sure in favor of black. Probably white position is lost. 40.Ngxf5 a4 41.Nc2 Kc7 42.Rxd8 Rxd8 43.Nd6 Ra8 44.Kg2 a3

WHITE TO MOVE

45.h3? White could a least pretend to try to save a game by playing Kf2 with the idea of sacrifice one night for black “c” and “b” pawns 45…a2 46.f5 Ra5 47.f6 Kd7 48.f7 Ke7 49.e6 Re5 50.Kf3 b5 51.Ne4 b4 52.Na1 Rxe6 53.Kf4 Rg6 54.Nb3 Rh6 55.Nec5 Rh5 56.Nd3 c5 57.Nf2 c4 White resigned 0–1

As a conclusion: game was played by both engines in relatively high level. There was no tactical mistake (which is pretty obvious) and final game score was a result of (numbers and weight) of strategical mistakes.