RYBKA
Beta SHREDDER
15th IPCCC 2005 round 5
Sicilian game B81
Topic: Active defense
comments by IM Piotr Murdzia
I can't remember if I have ever analyzed seriously a
game played by machines. The reason for that was simply - I didn't expect from
a computer anything else than high tactic level. Only after Iweta assured me
that Rybka has a good positional ability as, for example, the ability of
sacrifice exchange, I decided to draw attention how in fact things are.
1.e4 c5 2.Nf3 d6 3.d4 c:d4 4.N:d4 Nf6 5.Nc3 a6 6.Be3
e6
WHITE TO MOVE
7.g4 Aggressive continuation. 7...h6 8.Qf3 I don't like
this move, as queen will have to play soon the second time in order to
"free" f pawn. Better is 8.f3 or 8.Bg2 that was played by players
like Shirov or Anand. 8...Nc6
WHITE TO MOVE
9.h3 I think 9.Rg1 was better in order to have possibility to
advance h pawn to fourth rank immediately. 9...Bd7 10.000 b5 11.a3
The end of Rybka opening book. 11...Qb8
WHITE TO MOVE
12.Qe2 with the idea of f4-e5 12...Be7 13.f4 b4 14.a:b4
Q:b4 15.Bg2 Rb8 16.Nb3 Na5
WHITE TO MOVE
17.e5 White shouldn't wait longer with this move. Black
attack can be already very dangerous. 17...N:b3+ 18.c:b3 d:e5 19.f:e5
BLACK TO MOVE
19
Q:b3 However human intuition is strongly against such
moves as 19...Nh7, but I can't find a direct way to obtain a clear advantage
after Nh7 for white. Now let's better see what happens, because human brain, at
least mine! is not able to make a correct calculation here. If 19...Nh7 20.Qd3
00 21.Qc4! with slightly better position for white (21.Q:d7 is too dangerous
because of 21.. Q:b3 with attack).
WHITE TO MOVE
20.Ba7 After 20.ef6? Ba3 black cant complain on its
position too much J If 21.Rd3 then 21
B:b2+
22.Kd2 00 with strong attack.
20...Rc8 21.e:f6 B:f6 22.Qc2 Qb4 23.Rd3 Rc7 24.Bf2
Ba4 25.Qd2 00 with attack.
WHITE TO MOVE
It seems that black has more than enough compensation
here for a sacrificed piece. 26.Bg3! Good decision. Rybka avoids passive
defense and goes for a position with nonstandard material on board. A mistake
is to play 26.Kb1? because of 26
R:c3 27.R:c3 Rd8 28.Qc1 B:c3 29.Q:c3 Q:c3
30.b:c3 Rd2! and black will have winning endgame due to material advantage. After 26.Bg3 there is no more motive with
30
Rd2 attacking two bishops. 31.Rf1 Bb5+; 26.g5?! B:g5 27.Be3 Bb5 28.Rd4
R:c3+ 29.b:c3 Qa3+ 30.Kd1 e5 with strong attack. 26...Bg5 If 26...Rcc8
then 27.Kb1 and white is slightly better.
WHITE TO MOVE
27.B:c7 B:d2+ 28.R:d2 Rc8 29.Rd8+ R:d8 30.B:d8 The main task for Rybka now
is to create a coordination between its pieces.
WHITE TO MOVE
30...Qf4+ 31.Kb1 Bc2+ 32.K:c2 Qf2+ 33.Kb3 Q:g2 34.Rd1
Q:h3 35.Rd4 The
work to consolidate whites pieces is done.
BLACK TO MOVE
35...f5! Unfortunately
black is very quick with its pawns and its time to think how to make a draw. 36.g:f5
e:f5 37.Bc7 g5 38.Rd8+ Kf7
BLACK TO MOVE
39.Be5!? Rybka builds a drawish net around black king. 39...h5 40.Rd6 h4 41.Rf6+ Ke8 42.Re6+ Kf8
43.Rf6+ Ke7 44.Kc4! Qf1+ 45.Kd4 Qg1+ 46.Kc4 Qc1 47.Kd3 h3 48.Nd5+ Kd7 49.Rd6+
Ke8 50.Re6+ Kf7 51.Rf6+ Kg8 52.Ne7+ Kh7 53.N:f5 Qd1+ 54.Kc3 Qe1+ 55.Kd4 Qd2+
½½
WHITE TO MOVE
In conclusion I would like to say I am impressed how
Rybka copied with imbalanced material. I believe now Rybka helps me solving some
tough problems in positions I couldn't myself properly estimate. And by the way
I use "Rybka" word to call my wife, so I have special reason to love
Rybka J