An hard test position(a pawn sacrifice)

Discussion of anything and everything relating to chess playing software and machines.

Moderator: Ras

Uri Blass
Posts: 11152
Joined: Thu Mar 09, 2006 12:37 am
Location: Tel-Aviv Israel

An hard test position(a pawn sacrifice)

Post by Uri Blass »

http://www.iccf-webchess.com/MakeAMove.aspx?id=23706

[d]r2qkb1r/1b1n1ppp/p3p3/P2pP3/N1pN2P1/4BP2/1PPQ3P/R3K2R w KQkq - 0 15 bm f4


Can chess programs see advantage for white after 15.f4 Qh4+ 16.Bf2 Qxg4 or maybe white has no advantage and black blundered later in the game?
Top
yanquis1972
Posts: 1766
Joined: Wed Jun 03, 2009 12:14 am

Re: An hard test position(a pawn sacrifice)

Post by yanquis1972 »

[d]r3kb1r/1b1n1ppp/p3p3/P2pP3/N1pN1Pq1/8/1PPQ1B1P/R3K2R w KQkq -[d]
Top
zullil
Posts: 6442
Joined: Tue Jan 09, 2007 12:31 am
Location: PA USA
Full name: Louis Zulli

Re: An hard test position(a pawn sacrifice)

Post by zullil »

Uri Blass wrote:http://www.iccf-webchess.com/MakeAMove.aspx?id=23706

[d]r2qkb1r/1b1n1ppp/p3p3/P2pP3/N1pN2P1/4BP2/1PPQ3P/R3K2R w KQkq - 0 15 bm f4
In this position, Stockfish-1.7.1 (8 threads) likes O-O:

Code: Select all

Searching: r2qkb1r/1b1n1ppp/p3p3/P2pP3/N1pN2P1/4BP2/1PPQ3P/R3K2R w KQkq -
infinite: 1 ponder: 0 time: 0 increment: 0 moves to go: 0
 2     -0.53   00:01     2898 Bg5 Be7 Bxe7 Qxe7 
 3     -0.53   00:01     3164 Bg5 Be7 Bxe7 Qxe7 
 4     -0.57   00:01     3884 Bg5 Qc7 f4 h6 
 5     -0.65   00:01     5842 Bg5 Qc7 Nb6 Nxb6 axb6 Qxb6 
 6  <  -0.77   00:01     7582 Bg5 Qc7 Nb6 Qxe5+ Kf2 Bc5 
 6     -0.81   00:01    10394 Bg5 Qc7 f4 h5 Nb6 Nxb6 axb6 Qxb6 
 6     -0.57   00:01    11113 O-O Nxe5 Nb6 Ra7 Bg5 Be7 Bxe7 Qxe7 
 7     -0.57   00:01    13751 O-O Be7 Nb6 Nxb6 axb6 Qxb6 Nb3 Qc7 
 7     -0.48   00:01    15848 Bg5 Qc7 f4 h5 gxh5 Rxh5 O-O 
 8  <  -0.61   00:01    24618 Bg5 Qc7 f4 h5 gxh5 Rxh5 O-O Rb8 
 8  <  -0.73   00:01    32860 Bg5 Qc7 f4 h5 gxh5 Rxh5 O-O Rh8 
 8  <  -0.97   00:01    45900 Bg5 Qc7 f4 h6 Bh4 g5 
 8  >  -0.36   00:01    51423 O-O Be7 f4 O-O Nf3 
 8     -0.53   00:01    53100 O-O Be7 f4 O-O Nf3 Rb8 Nb6 Nc5 Ng5 
 9  >  -0.44   00:01    72249 O-O Be7 f4 O-O Nf3 Rb8 Bb6 Qe8 Bc7 
 9  <  -0.61   00:01    77821 O-O Be7 f4 O-O Nf3 Qc7 Nb6 Rab8 Ng5 Nc5 
 9     -0.48   00:01    91893 O-O Be7 f4 O-O Nf3 Qc7 Nb6 Rab8 Ng5 Bxg5 Nxd7 
                              Qxd7 fxg5 
10     -0.53   00:01   128383 O-O Be7 f4 O-O Nf3 Qc7 Nb6 Rab8 Na4 Bc6 Nb6 g5 
                              Qd4 gxf4 Qxf4 
11  >  -0.44   00:01   162962 O-O Nxe5 Bg5 f6 Rae1 
11     -0.40   00:01   168850 O-O Be7 f4 O-O Nf3 Qc7 Bb6 Qc6 Nd4 Qc8 Nc3 Re8 
12  <  -0.57   00:01   230468 O-O Be7 f4 O-O Nf3 Qc7 Bb6 Qc6 Nd4 Qc8 Nc3 Re8 
12     -0.53   00:01   316882 O-O Be7 f4 O-O Nf3 Qc7 Bb6 Qc6 Nd4 Qc8 Nc3 Re8 
                              Nf3 Nc5 
13     -0.61   00:01   443793 O-O Be7 f4 O-O Nf3 Bc6 Nb6 Rb8 Nd4 Bb7 Nf3 Nc5 
                              Ng5 Bc6 
14  >  -0.44   00:01   826170 O-O Nxe5 Bg5 f6 Rae1 fxg5 Rxe5 
14     -0.61   00:01   871775 O-O Be7 f4 O-O Nf3 Bc6 Nb6 Rb8 Qf2 Qc7 Rfd1 Rfe8 
                              Nd4 Bb7 Nf3 Nc5 
15  >  -0.53   00:01    1362k O-O Nxe5 Bg5 Be7 Bxe7 Qxe7 Rfe1 Qc7 Qe3 
15  <  -0.69   00:01    1507k O-O Be7 f4 O-O Nf3 Bc6 Nb6 Rb8 Qf2 Qc7 Rfd1 Rfe8 
                              Nd4 Bb7 Ne2 Nc5 Nc3 
15     -0.53   00:01    2560k O-O Be7 f4 O-O Nf3 Bc6 Nb6 Rb8 Qf2 Qc7 Rfd1 Rfe8 
                              Nd4 Bb7 Ne2 Nc5 Nc3 Bc8 Nxc8 Rexc8 
16  >  -0.44   00:02    3272k O-O Nxe5 Bg5 Be7 Bxe7 Qxe7 Rfe1 Qc7 Qe3 
16  >  -0.36   00:02    3701k O-O Nxe5 Nb6 Rb8 Bf4 Bd6 Rae1 Qc7 Qe3 
16  >  -0.20   00:02    3987k O-O Nxe5 Nb6 Rb8 Bf4 Bd6 Rae1 Qc7 Qe3 
16  <  -0.61   00:02    5749k O-O Be7 f4 O-O f5 Nxe5 Nb6 Rb8 fxe6 fxe6 Bf4 Qd6 
                              Rae1 c3 
16     -0.12   00:02    6901k O-O Be7 f4 O-O f5 exf5 Nxf5 Nxe5 Nb6 Rb8 Nxd5 Bh4 
                              Bf4 Re8 Rad1 Re6 Bxe5 Rxe5 
17     +0.00   00:04   14303k O-O Be7 f4 O-O f5 exf5 Nxf5 Nxe5 Nxe7+ Qxe7 Bc5 
                              Qh4 Bxf8 Qxg4+ Qg2 Qd4+ Qf2 Qg4+ Qg2 
18     +0.00   00:04   16934k O-O Be7 f4 O-O f5 exf5 Nxf5 Nxe5 Nxe7+ Qxe7 Bc5 
                              Qh4 Bxf8 Qxg4+ Qg2 Qd4+ Qf2 Qg4+ Qg2 
19  <  -0.08   00:05   22708k O-O Nxe5 Nb6 Rb8 Bf4 Nc6 Bxb8 Bc5 c3 Qxb8 Kg2 h5 
                              g5 Nxd4 cxd4 Bd6 f4 
19  <  -0.16   00:05   23956k O-O Nxe5 Nb6 Rb8 Bf4 Nc6 Bxb8 Bc5 c3 Qxb8 Kg2 h5 
                              g5 Nxd4 cxd4 Bd6 f4 Bc6 
19  <  -0.32   00:05   25673k O-O Nxe5 Nb6 Rb8 Bf4 Nc6 Nxc6 Bxc6 Bxb8 Bc5+ Kg2 
                              Qxb8 Qg5 O-O Nxc4 Bd4 
19     +0.00   00:07   32243k O-O Nxe5 Nb6 Rb8 Rae1 Nc6 Nxc6 Bxc6 Bd4 h5 Re2 
                              Rb7 Qe3 hxg4 fxg4 Qh4 Qf4 Bd6 Qxd6 Qxg4+ Rg2 
                              Qxd4+ Rgf2 Qg4+ Kh1 
20  <  -0.08   00:07   35338k O-O Nxe5 Nb6 Rb8 Rae1 Nc6 Nxc6 Bxc6 Bd4 h5 Re2 
                              Rb7 Qe3 hxg4 fxg4 Qh4 Qf4 Qh6 g5 Qh4 
20  <  -0.16   00:08   37496k O-O Nxe5 Nb6 Rb8 Rae1 Nc6 Nxc6 Bxc6 Bd4 h5 Re2 
                              Rb7 Qe3 hxg4 fxg4 Qh4 Qf4 Qh6 g5 Qh4 
20  <  -0.32   00:08   39890k O-O Nxe5 Nb6 Rb8 Bf4 Nc6 Nxc6 Bxc6 Bxb8 Qxb8 Kg2 
                              h5 g5 Bc5 Rfe1 O-O h4 Qc7 f4 Bd6 Kg3 Bc5 
20     -0.53   00:09   47683k O-O Nxe5 Nb6 Rb8 Bf4 Nc6 Nxc6 Bxc6 Bxb8 Qxb8 Kg2 
                              Bd6 f4 Bc5 Kh3 h5 g5 O-O Kh4 g6 Kh3 Qc7 Rae1 Rb8 
21     -0.48   00:12   63378k O-O Nxe5 Nb6 Rb8 Bf4 Nc6 Nxc6 Bxc6 Bxb8 Qxb8 Kg2 
                              Bd6 f4 Bc5 Kh3 h5 g5 O-O Qc3 Bd6 Qd2 Re8 Rae1 Qd8 
                              Kg2 d4+ Kg1 
22  >  -0.16   00:17   98573k O-O Be7 f4 O-O f5 exf5 Nxf5 Nxe5 Nb6 Rb8 Nxd5 
                              Bxd5 Qxd5 Rb5 Qxd8 Bxd8 Nd6 Rd5 Bf4 Nxg4 Nxc4 Bf6 
                              h3 Rc8 Nb6 Bd4+ Kh1 
22     -0.16   00:27  175177k O-O h5 g5 g6 f4 Be7 Nf3 O-O h3 Rb8 Ba7 Rc8 Nd4 
                              Ra8 Bb6 Qc8 Kg2 Nb8 Rfd1 Re8 Nc3 Nc6 Qe3 Nb4 
23     -0.12   00:32  207309k O-O h5 g5 g6 f4 Be7 Nf3 O-O h3 Rb8 Ba7 Rc8 Nd4 
                              Ra8 Bb6 Qc8 Kg2 Nb8 Rfd1 Kg7 Rf1 Rg8 Rfd1 Nd7 Nc3 
                              Rb8 Nf3 
24  <  -0.32   00:47  315723k O-O Be7 f4 O-O f5 Nxe5 Nb6 Nxg4 fxe6 fxe6 Nxa8 e5 
                              Rxf8+ Qxf8 Nc7 exd4 Bxd4 Bd6 Rf1 Bxh2+ Qxh2 Qxf1+ 
24     +0.00   02:10  906376k O-O Nxe5 Nb6 Rb8 Rae1 Nc6 Bg5 Be7 Bxe7 Qxe7 Nf5 
                              Qc5+ Kg2 Qxa5 Nd6+ Ke7 Nf5+ Ke8 Nd6+ Ke7 
25     +0.00   02:18  956065k O-O Nxe5 Nb6 Rb8 Rae1 Nc6 Bg5 Be7 Bxe7 Qxe7 Nf5 
                              Qc5+ Kg2 Qxa5 Nd6+ Ke7 Nf5+ Ke8 Nd6+ Ke7 
26     +0.00   02:45    1146M O-O Nxe5 Nb6 Rb8 Rae1 Nc6 Bg5 Be7 Bxe7 Qxe7 Nf5 
                              Qc5+ Kg2 Qxa5 Nd6+ Ke7 Nf5+ Ke8 Nd6+ Ke7 
27     +0.00   03:07    1302M O-O Nxe5 Nb6 Rb8 Rae1 Nc6 Bg5 Be7 Bxe7 Qxe7 Nf5 
                              Qc5+ Kg2 Qxa5 Nd6+ Ke7 Nf5+ Ke8 Nd6+ Ke7 
28     +0.00   03:54    1640M O-O Nxe5 Nb6 Rb8 Rae1 Nc6 Bg5 Be7 Bxe7 Qxe7 Nf5 
                              Qc5+ Kg2 Qxa5 Nd6+ Ke7 Nf5+ Ke8 Nd6+ Ke7 
29     +0.00   05:09    2185M O-O Nxe5 Nb6 Rb8 Rae1 Nc6 Bg5 Be7 Bxe7 Qxe7 Nf5 
                              Qc5+ Kg2 Qxa5 Nd6+ Ke7 Nf5+ Ke8 Nd6+ Ke7 
30     +0.00   06:54    2955M O-O Nxe5 Nb6 Rb8 Rae1 Nc6 Bg5 Be7 Bxe7 Qxe7 Nf5 
                              Qc5+ Kg2 Qxa5 Nd6+ Ke7 Nf5+ Ke8 Nd6+ Ke7 
31     +0.00   11:01    4771M O-O Nxe5 Nb6 Rb8 Rae1 Nc6 Bg5 Be7 Bxe7 Qxe7 Nf5 
                              Qc5+ Kg2 Qxa5 Nd6+ Ke7 Nf5+ Ke8 Nd6+ Ke7 
32  <  -0.08   25:55   11478M O-O Rb8 f4 Qh4 Qg2 
32  <  -0.16   36:26   16178M O-O Rb8 Nb6 Bc5 Nxd7 Qxd7 Nf5 Bxe3+ Nxe3 
32     +0.00 1:52:24   50043M O-O Nxe5 Nb6 Rb8 Rae1 Nc6 Bg5 Be7 Bxe7 Qxe7 Nf5 
                              Qc5+ Kg2 Qxa5 Nd6+ Ke7 Nf5+ Ke8 Nd6+ Ke7 

Nodes: 50607745295
Nodes/second: 7424887
Best move: O-O
Ponder move: Nxe5
Top
yanquis1972
Posts: 1766
Joined: Wed Jun 03, 2009 12:14 am

Re: An hard test position(a pawn sacrifice)

Post by yanquis1972 »

i went a full 10 moves ahead in the evaluation & this is stockfish's evaluation on an octal ---



r3k2r/1b1nbpqp/p3p1p1/P2pP3/N1p2P2/4BN1R/1PP3QP/2KR4 w kq -

Engine: Stockfish 1.7 JA 64bit 8C (1024 MB)
by Tord Romstad, Marco Costalba, Joona Kii

21.00 0:01 0.00 11.f5 exf5 12.Bh6 Qg8 13.Qg1 Bf8
14.Bd2 Be7 15.Bh6 (7.557.891) 6210

22.01 0:09 +0.08++ 11.f5 Nxe5 12.fxe6 Nxf3 13.Bh6 Bg5+
14.Bxg5 Nxg5 15.Qxg5 fxe6 16.Nb6 Rd8
17.Rf1 Rf8 18.Rxf8+ Qxf8 19.Rxh7 Qf1+
20.Kd2 Qf2+ 21.Kc3 Qe1+ 22.Kd4 Qf2+
23.Ke5 Qe2+ 24.Kf6 (67.232.524) 7280

22.01 0:13 +0.16++ 11.f5 Nxe5 12.fxe6 O-O 13.Nb6 Nxf3
14.Bh6 Qe5 15.Rxf3 fxe6 16.Nd7 Qc7
17.Nxf8 Bxf8 18.Bxf8 Rxf8 19.Rxf8+ Kxf8
20.Rf1+ Kg8 21.Qg5 (98.238.533) 7365

22.01 0:15 -0.08-- 11.f5 Nxe5 12.fxe6 O-O 13.Nb6 Nxf3
14.Bh6 Nh4 15.Rxh4 Qe5 16.Bxf8 Rxf8
17.exf7+ Rxf7 18.Rg4 Bf8 19.Nxd5 Bh6+
20.Kb1 Rd7 (114.151.490) 7391

22.01 0:18 -0.08 11.f5 Nxe5 12.fxe6 O-O 13.Nb6 Nxf3
14.Bh6 Nh4 15.Rxh4 Qe5 16.Rh3 Bf6
17.c3 Qxe6 18.Re3 Be5 19.Rxe5 Qxe5
20.Nd7 Qd6 21.Nxf8 f5 22.Re1 Rxf8
23.Bxf8 Kxf8 24.Qh3 (135.609.862) 7398

23.01 0:23 0.00++ 11.f5 Nxe5 12.fxe6 O-O 13.Nb6 Nxf3
14.Bh6 Nh4 15.Rxh4 Qe5 16.Rh3 Bf6
17.c3 Qxe6 18.Re3 Be5 19.Rxe5 Qxe5
20.Nd7 Qd6 21.Nxf8 f5 22.Qe2 Rxf8
23.Bxf8 Kxf8 24.Qxc4 (176.131.295) 7447

23.01 0:25 0.00 11.f5 Nxe5 12.fxe6 O-O 13.Nb6 Nxf3
14.Bh6 Nh4 15.Rxh4 Qe5 16.Nxa8 Bxh4
17.Nb6 Qh5 18.Bxf8 Bg5+ 19.Rd2 Kxf8
20.Qg3 Bxd2+ 21.Kxd2 Qh6+ 22.Ke2 Qh5+
23.Kd2 (191.266.585) 7462

24.01 0:36 0.00 11.f5 Nxe5 12.fxe6 Nxf3 13.Bh6 Bg5+
14.Bxg5 Nxg5 15.Qxg5 fxe6 16.Nb6 Rd8
17.Rf1 Rf8 18.Rxf8+ Qxf8 19.Rxh7 Qf1+
20.Kd2 Qf2+ 21.Kc3 d4+ 22.Kb4 Qf8+
23.Kxc4 Bd5+ 24.Kd3 (276.271.415) 7568

25.01 0:50 0.00 11.f5 Nxe5 12.fxe6 Nxf3 13.Bh6 Bg5+
14.Bxg5 Nxg5 15.Qxg5 fxe6 16.Nb6 Rd8
17.Rf1 Rf8 18.Rxf8+ Qxf8 19.Rxh7 Qf1+
20.Kd2 Qf2+ 21.Kc3 d4+ 22.Kb4 Qf8+
23.Kxc4 Bd5+ 24.Kd3 (385.892.858) 7658

26.01 1:27 -0.08-- 11.f5 exf5 12.Bh6 Qg8 13.Qg1 Bf8
14.Bd2 h6 15.Bc3 g5 16.e6 fxe6
17.Bxh8 Qxh8 18.Nb6 Rd8 (673.900.550) 7723

26.01 1:51 0.00 11.f5 Nxe5 12.fxe6 Nxf3 13.Bh6 Bg5+
14.Bxg5 Nxg5 15.Qxg5 fxe6 16.Nb6 Rd8
17.Rf1 Rf8 18.Rxf8+ Qxf8 19.Rxh7 Qf1+
20.Kd2 Qf2+ 21.Kc3 d4+ 22.Kb4 Qf8+
23.Kxc4 Bd5+ 24.Kd3 (862.048.272) 7715

27.01 2:28 0.00 11.f5 Nxe5 12.fxe6 Nxf3 13.Bh6 Bg5+
14.Bxg5 Nxg5 15.Qxg5 fxe6 16.Nb6 Rd8
17.Rf1 Rf8 18.Rxf8+ Qxf8 19.Rxh7 Qf1+
20.Kd2 Qf2+ 21.Kc3 d4+ 22.Kb4 Qf8+
23.Kxc4 Bd5+ 24.Kd3 (1.155.463.319) 7784

28.01 4:05 0.00 11.f5 Nxe5 12.fxe6 Nxf3 13.Bh6 Bg5+
14.Bxg5 Nxg5 15.Qxg5 fxe6 16.Nb6 Rd8
17.Rf1 Rf8 18.Rxf8+ Qxf8 19.Rxh7 Qf1+
20.Kd2 Qf2+ 21.Kc3 d4+ 22.Kb4 Qf8+
23.Kxc4 Bd5+ 24.Kd3 (1.929.176.585) 7844

29.01 6:42 0.00 11.f5 Nxe5 12.fxe6 Nxf3 13.Bh6 Bg5+
14.Bxg5 Nxg5 15.Qxg5 fxe6 16.Nb6 Rd8
17.Rf1 Rf8 18.Rxf8+ Qxf8 19.Rxh7 Qf1+
20.Kd2 Qf2+ 21.Kc3 d4+ 22.Kb4 Qf8+
23.Kxc4 Bd5+ 24.Kd3 (3.191.099.404) 7922

30.01 11:55 0.00 11.f5 Nxe5 12.fxe6 Nxf3 13.Bh6 Bg5+
14.Bxg5 Nxg5 15.Qxg5 fxe6 16.Nb6 Rd8
17.Rf1 Rf8 18.Rxf8+ Qxf8 19.Rxh7 Qf1+
20.Kd2 Qf2+ 21.Kc3 d4+ 22.Kb4 Qf8+
23.Kxc4 Bd5+ 24.Kd3 (5.690.755.004) 7953

31.01 28:37 +0.08++ 11.f5 exf5 12.Bh6 Qg8 13.Qg1 (13.564.077.478) 7895

31.01 36:50 +0.16++ 11.f5 exf5 12.Bh6 Qg8 13.Qg1 Bf8
14.Bd2 Be7 15.Bc3 (17.312.688.871) 7833

31.01 53:01 +0.32++ 11.f5 Nxe5 12.Bh6 Qf6 13.Nxe5 (24.738.932.492) 7776

31.01 60:44 0.00 11.f5 Nxe5 12.Bh6 Qf6 13.Nxe5 Qxe5
14.fxe6 fxe6 15.Nb6 Rd8 16.Rf1 g5
17.Rg3 Bf6 18.c3 Rg8 19.Nxc4 dxc4
20.Qxb7 Qxa5 21.Re3 Qa1+ 22.Kc2 Qa4+
23.Kc1 Qa1+ (28.446.195.277) 7805

32.01 65:23 +0.08++ 11.f5 Nxe5 12.Bh6 Qf6 13.Nxe5 Qxe5
14.fxe6 fxe6 (30.660.037.113) 7814

32.01 68:36 +0.16++ 11.f5 exf5 12.Bh6 Qg8 13.Qg1 Kd8
14.e6 fxe6 15.Nb6 Nxb6 16.Qxb6+ Kc8 (32.151.026.298) 7810

32.01 72:37 +0.32++ 11.f5 Nxe5 12.Bh6 (34.001.074.870) 7803

32.01 128:49 +0.44 11.f5 Nxe5 12.Bh6 Qf6 13.Nxe5 Qxe5
14.fxe6 fxe6 15.Nb6 Rb8 16.Re3 d4
17.Rxe5 Bxg2 18.Rxe6 Kf7 19.Re2 Bh3
20.Rf2+ Bf5 21.Nxc4 Rhc8 22.Rxd4 Rb5
23.b3 Kg8 24.Rfd2 (60.639.784.608) 7844

33.01 169:08 +0.44 11.f5 Nxe5 12.Bh6 Qf6 13.Nxe5 Qxe5
14.fxe6 fxe6 15.Nb6 Rb8 16.Re3 d4
17.Rxe5 Bxg2 18.Rxe6 Kf7 19.Re2 Bh3
20.Rf2+ Bf5 21.Nxc4 Rhc8 22.Rxd4 Rb5
23.b3 Kg8 24.Rfd2 (80.106.883.794) 7893
Top
kgburcham
Posts: 2016
Joined: Sun Feb 17, 2008 4:19 pm

Re: An hard test position(a pawn sacrifice)

Post by kgburcham »

[d] r2qkb1r/1b1n1ppp/p3p3/P2pP3/N1pN2P1/4BP2/1PPQ3P/R3K2R w KQkq -

Rybka 3 (2048 MB)

13.01 0:01 -0.17 15.O-O Be7 16.f4 O-O 17.Nf3 h6 18.f5 Qc7 19.f6 gxf6 (446.602) 406
14.01 0:02 -0.14 15.O-O Be7 16.f4 O-O 17.Nf3 h6 18.f5 Qc7 19.Nb6 Rab8 20.f6 (875.368) 404
15.01 0:03 -0.14 15.O-O Be7 16.f4 O-O 17.Nf3 Rb8 18.Ba7 Rc8 19.Kg2 h6 20.h3 Ra8 (1.440.521) 411
16.01 0:07 -0.14 15.O-O Be7 16.f4 O-O 17.Nf3 Rb8 18.Ba7 Rc8 19.Be3 h6 20.Nb6 Rb8 (2.907.120) 413
17.01 0:14 -0.13 15.O-O Be7 16.f4 O-O 17.Nf3 Rb8 18.Ba7 Rc8 19.Qe3 h6 20.Bb6 Qe8 21.Nd4 Bb4 (5.980.363) 421
18.01 0:38 -0.07 15.O-O Be7 16.f4 O-O 17.Nf3 Qc7 18.Bb6 Qc6 19.f5 exf5 20.gxf5 Rae8 21.Nd4 Qc8 22.Qg2 (15.859.336) 418
19.01 3:02 0.00 15.O-O Be7 16.f4 O-O 17.f5 Nxe5 18.Nb6 Nxg4 19.fxe6 fxe6 20.Nxa8 e5 21.Nb6 Nxe3 22.Qxe3 exd4 23.Qe6+ Kh8 24.Rae1 Bd6 25.Rxf8+ Bxf8 26.Qd7 Qg5+ 27.Kh1 Qh4 28.Rf1 (79.570.405) 446
20.01 4:41 0.00 15.O-O Be7 16.f4 O-O 17.f5 Nxe5 18.Nb6 Nxg4 19.fxe6 fxe6 20.Nxa8 e5 21.Nb6 Nxe3 22.Qxe3 exd4 23.Qe6+ Kh8 24.Rae1 Bd6 25.Rxf8+ Bxf8 26.Qd7 Qg5+ 27.Kh1 Qh4 28.Rf1 (124.605.077) 453
21.01 7:02 0.00 15.O-O Be7 16.f4 O-O 17.f5 Nxe5 18.Nb6 Nxg4 19.fxe6 fxe6 20.Nxa8 e5 21.Nb6 Nxe3 22.Qxe3 exd4 23.Qe6+ Kh8 24.Rae1 Bd6 25.Rxf8+ Bxf8 26.Qd7 Qg5+ 27.Kh1 Qh4 28.Rf1 (183.023.589) 444




After 15.f4

[d] r2qkb1r/1b1n1ppp/p3p3/P2pP3/N1pN1PP1/4B3/1PPQ3P/R3K2R b KQkq -

Rybka 3

13.01 0:01 -0.42 15...Qh4+ 16.Qf2 Bb4+ 17.Nc3 Qe7 18.O-O O-O 19.Nf3 Rab8 20.Bd4 h6 21.Na4 Bc6 22.Nb6 (596.731) 355
14.01 0:02 -0.42 15...Qh4+ 16.Qf2 Bb4+ 17.Nc3 Qe7 18.O-O O-O 19.Nf3 Rab8 20.Bd4 h6 21.Na4 Bc6 22.Nb6 (750.300) 346
15.01 0:08 -0.62++ 15...Qh4+ (3.302.650) 390
15.01 0:10 -0.61 15...Qh4+ 16.Qf2 Bb4+ 17.Nc3 Qd8 18.O-O O-O 19.Nf3 Bxa5 20.Na4 Rc8 21.c3 Re8 22.Qc2 Qe7 (4.031.325) 394
16.01 0:20 -0.54 15...Qh4+ 16.Qf2 Bb4+ 17.Nc3 Qd8 18.O-O O-O 19.Nf3 Bxa5 20.Bd4 h6 21.Na4 Qc7 22.Nc5 Nxc5 23.Bxc5 Rfc8 24.Bd6 Qd8 25.Bc5 Bc6 (8.037.069) 406
17.01 0:25 -0.54 15...Qh4+ 16.Qf2 Bb4+ 17.Nc3 Qd8 18.O-O O-O 19.Nf3 Bxa5 20.Bd4 h6 21.Na4 Qc7 22.Nc5 Nxc5 23.Bxc5 Rfc8 24.Bd6 Qd8 25.Bc5 Bc6 (10.042.890) 399
18.01 0:43 -0.56 15...Qh4+ 16.Qf2 Bb4+ 17.Nc3 Qd8 18.O-O O-O 19.Nf3 Bxa5 20.Bd4 h6 21.Na4 Bb4 22.Nc5 Qc7 23.Nxd7 Qxd7 24.Bc5 Bxc5 25.Qxc5 Rfc8 26.Qa3 Bc6 (17.665.549) 411
19.01 1:25 -0.55 15...Qh4+ 16.Qf2 Bb4+ 17.Nc3 Qd8 18.O-O O-O 19.Nf3 Bxa5 20.Bd4 Bc7 21.Na4 Re8 22.Nc5 Nxc5 23.Bxc5 Rb8 24.Ba7 Rc8 25.Qe3 Qd7 26.Bb6 (35.589.504) 424
20.01 2:09 -0.55 15...Qh4+ 16.Qf2 Bb4+ 17.Nc3 Qd8 18.O-O O-O 19.Nf3 Bxa5 20.Bd4 Bc7 21.Na4 Re8 22.Nc5 Nxc5 23.Bxc5 Rb8 24.Ba7 Rc8 25.Qe3 Qd7 26.Bb6 (53.044.542) 420
21.01 5:50 -0.58 15...Qh4+ 16.Qf2 Bb4+ 17.Nc3 Qd8 18.O-O O-O 19.Nf3 Bxa5 20.Bd4 Bc7 21.Na4 Re8 22.Nc5 Nxc5 23.Bxc5 Rb8 24.Kg2 h6 25.Qe3 Qd7 26.Nd4 Rbc8 (153.367.894) 447
22.01 22:39 -0.60 15...Qh4+ 16.Qf2 Bb4+ 17.Nc3 Qd8 18.O-O O-O 19.Nf3 Bxa5 20.Bd4 Bc7 21.Na4 Re8 22.Nc5 Nxc5 23.Bxc5 Rb8 24.Kg2 h6 25.Qe3 Qd7 26.Nd4 Rbc8 (613.563.093) 462



If you force 15.f4, Rybka prefers this line 15.f4 Qh4+ 16.Qf2 Bb4+ 17.Nc3 Qd8
Note: Rybka does not capture the pawn even at shallow depth---then retreats the Queen to d8.

[d] r3k2r/1b1n1ppp/p3p3/P2pP3/1bpN1PPq/2N1B3/1PP2Q1P/R3K2R b KQkq -

20.00 3:12 -0.59 17...Qd8 18.O-O O-O 19.Nf3 Bxa5 (84.149.436) 447
21.01 5:35 -0.59 17...Qd8 18.O-O O-O 19.Nf3 Bxa5 20.Bd4 Bc7 21.Na4 Re8 22.b3 cxb3 23.cxb3 h6 24.Rfc1 Rc8 25.b4 Qe7 26.Nc5 Nxc5 27.Bxc5 Qd7 28.Nd4 Bd8 (154.719.572) 472
22.01 15:11 -0.53 17...Qd8 18.O-O Bxa5 19.Na4 Rb8 20.Nf3 O-O 21.Ba7 Rc8 22.Bd4 Qe7 (432.513.910) 485
23.01 37:33 -0.56 17...Qd8 18.h4 Bxa5 19.h5 h6 20.Qg3 Nc5 (1.111.922.080) 505
24.01 57:53 -0.55 17...Qd8 18.h4 Bxa5 19.h5 h6 20.Qg3 Nc5 21.O-O Bxc3 22.bxc3 Ne4 23.Qf3 Qc7 24.g5 O-O 25.gxh6 gxh6 26.f5 Kh7 27.Bf4 exf5 28.Nxf5 d4 29.Rab1 Ra7 30.Rxb7 Qxb7 (1.680.126.334) 495
best move: Qh4-d8 time: 102:40.605 min n/s: 481.359 nodes: 2.895.962.112
Top
Uri Blass
Posts: 11152
Joined: Thu Mar 09, 2006 12:37 am
Location: Tel-Aviv Israel

Re: An hard test position(a pawn sacrifice)

Post by Uri Blass »

Rybka does not capture the pawn after Qf2 but she capture the pawn after Bf2 and the idea of f4 is to reply Qh4+ with Bf2 and not with Qf2.
Top
Mincho Georgiev
Posts: 454
Joined: Sat Apr 04, 2009 6:44 pm
Location: Bulgaria

Re: An hard test position(a pawn sacrifice)

Post by Mincho Georgiev »

Pawny 0.1.9:

Code: Select all

setboard r2qkb1r/1b1n1ppp/p3p3/P2pP3/N1pN2P1/4BP2/1PPQ3P/R3K2R w KQkq - 0 15
go
 1 4        -2.73 d4e6 f7e6
 1 8        -1.21 e1g1 d7e5
 1 12       -1.18 e1c1 d7e5
 2 217      -0.13 e3g5 d8c7
 3 354      -0.11 e3g5 f8e7 g5e7 d8e7
 4 225      -0.11 e3g5 f8e7 g5e7 d8e7
 6 6829     -0.46 e3g5 d8c7 f3f4 h7h5 h1g1 h5g4 g1g4
 7 12617    -0.35 e3g5 d8c7 f3f4 h7h5 g4h5 h8h5 a4c3
 8 415624   -0.71 e3g5 d8c7 f3f4 h7h6 g5h4 g7g5 h4g3 g5f4 d2f4 c7a5 c2c3
 8 488235   -0.66 f3f4 d8h4 d2f2 h4g4 h1g1 g4h5 a4c3 a8c8 a1d1
 9 60566    -0.72 f3f4 d8h4 d2f2 h4g4 h1g1 g4h5 a4c3 a8c8 a1d1 h7h6
10 132889   -0.66 f3f4 d8h4 d2f2 h4g4 h1g1 g4h5 a4c3 g7g6 g1g5
11 403678   -0.69 f3f4 d8h4 d2f2 h4g4 h1g1 g4h5 d4f3 a8c8 e1c1 h5f5 a4b6 c8d8
12 664098   -0.68 f3f4 d8h4 d2f2 h4g4 h1g1 g4h5 d4f3 h7h6 e1c1 h5f5 a4c3 a8c8 f2e2
13 1413933  -0.72 f3f4 d8h4 d2f2 h4g4 h1g1 g4h5 a4b6 a8d8 d4e2 f8b4 c2c3
14 3580842  -0.67 f3f4 d8h4 d2f2 h4g4 h1g1 g4h5 d4f3 h7h6 e1c1 a8d8 a4c3
   641 Kn/s,  37.78 sec

move f3f4
Top
User avatar
Eelco de Groot
Posts: 4696
Joined: Sun Mar 12, 2006 2:40 am
Full name:   Eelco de Groot

Re: An hard test position(a pawn sacrifice)

Post by Eelco de Groot »

No new insights from Rainbow Serpent here but I'm posting the results anyway; Rainbow Serpent could not see advantage from playing 15. f4, at least not at the depths that could be reached on an Athlon. In the game position, before f4:

[d]r2qkb1r/1b1n1ppp/p3p3/P2pP3/N1pN2P1/4BP2/1PPQ3P/R3K2R w KQkq -

Engine: Rainbow Serpent 1.6.3s(dc) Build 286 (Athlon 2009 MHz, 256 MB)
by Tord Romstad, Marco Costalba, Joona Kiiski Modifications: Dann Corbit

1.00 0:00 +0.12 15.Bg5 (828) 3

2.00 0:00 -0.20 15.Bg5 Be7 16.Bxe7 Qxe7 (958) 3

3.00 0:00 -0.20 15.Bg5 Be7 16.Bxe7 Qxe7 17.Nb6 O-O
18.Nxa8 Bxa8 19.Qf4 (31.820) 88

4.00 0:00 +0.16 15.Bg5 Qc7 16.f4 Bc5 17.Nxc5 Nxc5
18.Qb4 O-O 19.O-O (60.750) 143

5.00 0:00 +0.15 15.Bg5 Qc7 16.O-O h6 17.Bh4 g5
18.Bg3 Be7 19.Nb6 Nxb6 20.axb6 Qxb6 (214.191) 285

6.00 0:01 -0.21-- 15.Bg5 Qb8 16.Bf4 Bc5 17.Nxc5 Nxc5
18.O-O O-O (681.080) 403

7.01 0:05 +0.16 15.Bg5 Qc7 16.O-O h6 17.Bh4 g5
18.Bf2 Be7 19.Nb6 Nxb6 20.axb6 Qxb6 (2.680.989) 460

8.01 0:06 -0.20 15.Bg5 Qc7 16.O-O h6 17.Bh4 g5
18.Bg3 Be7 19.Rae1 O-O 20.f4 gxf4
21.Qxf4 (2.810.013) 458

9.01 0:11 +0.16 15.Bg5 Qc7 16.O-O h6 17.Bh4 g5
18.Bg3 h5 19.gxh5 Rxh5 20.f4 Rh8
21.fxg5 Qxa5 22.Qxa5 (5.067.917) 454

10.01 0:31 -0.32 15.Bg5 Qc7 16.O-O Bc5 17.Nxc5 Nxc5
18.Bh4 O-O 19.Qb4 Rac8 20.Rae1 Rce8 (13.991.038) 444

11.01 0:44 -0.24 15.Bg5 Qc7 16.O-O Bc5 17.Nxc5 Nxc5
18.Bh4 O-O 19.Qb4 Rac8 20.Rae1 Rce8
21.Re2 Rb8 (19.959.608) 450

12.01 1:07 -0.16 15.Bg5 Qc7 16.O-O Bc5 17.Nxc5 Nxc5
18.Qb4 O-O 19.Kg2 h6 20.Bd2 f6 21.f4 fxe5
22.fxe5 Rac8 23.Rxf8+ Rxf8 24.h3 (30.927.678) 461

13.01 2:16 0.00 15.Bg5 Qc7 16.O-O h6 17.Bh4 g5
18.Bg3 Bg7 19.Qb4 Bf8 20.Qd2 (63.513.584) 463

14.01 2:27 -0.40-- 15.Bg5 Qc7 16.O-O h6 17.Bh4 g5
18.Bg3 Bg7 19.Qb4 h5 20.Nb6 h4
21.Bf2 Bxe5 22.Qa4 c3 (68.464.541) 463

14.20 3:26 -0.36 15.O-O Be7 16.f4 O-O 17.Nf3 Bc6
18.Nb6 Rb8 19.Nd4 Qc7 20.f5 exf5
21.Nxc6 Qxc6 22.Rxf5 Bc5 23.Bxc5 Be3 (95.967.413) 465

15.01 5:32 0.00 15.O-O Be7 16.f4 O-O 17.f5 Nxe5
18.fxe6 Qc7 19.exf7+ Rxf7 20.Rxf7 Nxf7
21.Nb6 Re8 22.Bf4 Qc5 23.Qe3 Qb4
24.Nf5 g5 25.Nxe7+ Rxe7 26.Qxe7 (155.692.042) 468

16.01 11:10 -0.08 15.O-O Be7 16.f4 O-O 17.f5 Nxe5
18.fxe6 fxe6 19.Nb6 Nxg4 20.Nxa8 e5
21.Nb6 Nxe3 22.Qxe3 exd4 23.Qe6+ Kh8
24.Rf7 Rxf7 25.Qxf7 d3 26.cxd3 Bc5+
27.Kh1 Bc6 28.Qe6 (320.342.916) 477

17.01 35:11 -0.20 15.O-O Be7 16.f4 O-O 17.f5 Nxe5
18.fxe6 fxe6 19.Nb6 Nxg4 20.Nxa8 e5
21.Nb6 Nxe3 22.Qxe3 exd4 23.Qe6+ Kh8
24.Rxf8+ Bxf8 25.Qd7 Qg5+ 26.Kh1 d3
27.Rf1 Qe7 28.cxd3 (1.012.830.569) 479

18.01 78:47 +0.12++ 15.O-O Be7 16.f4 O-O 17.f5 Nxe5
18.fxe6 fxe6 19.Nb6 Nxg4 20.Nxa8 e5
21.Nb6 Nxe3 22.Qxe3 (2.268.891.642) 479

19.01 102:31 0.00 15.O-O Be7 16.f4 O-O 17.f5 Nxe5
18.fxe6 fxe6 19.Nb6 Nxg4 20.Nxa8 e5
21.Nb6 Nxe3 22.Qxe3 exd4 23.Qe6+ Kh8
24.Rae1 Bb4 25.Rxf8+ Bxf8 26.Re5 d3
27.cxd3 cxd3 28.Qe8 (3.045.054.201) 494

20.01 233:13 0.00 15.O-O Be7 16.f4 O-O 17.f5 Nxe5
18.Nb6 Nxg4 19.fxe6 fxe6 20.Nxa8 e5
21.Nb6 Nxe3 22.Qxe3 exd4 23.Qe6+ Kh8
24.Rae1 Bb4 25.Rxf8+ Bxf8 26.Re5 d3
27.cxd3 cxd3 28.Qe8 (6.862.115.138) 490

best move: O-O time: 269:01.875 min n/s: 511.439 nodes: 8.253.181.038

I think these PV look more similar to Rybka than to the new Stockfish :) But since the outcome is a draw in both cases even maybe after f4 if you believe Rainbow Serpent, there are probably more ways of achieving this. 15. f4 was considered but never chosen.

To get a bit deeper I went to the position after 18. Rg5 when Black has the choice of taking on h2 or the retreat of the Queen to h6. This was a long run but on my machine I think it could not really see deep enough, Black still has 0.00 on the last PV, the score never goes lower than that. But to check if it really stays at 0.00 I probably would have had to move the search forward further into the PV.

[d]r3kb1r/1b1n1ppp/p3p3/P2pP1Rq/N1pN1P2/8/1PPQ1B1P/R3K3 b Qkq -

Engine: Rainbow Serpent 1.6.3s(dc) Build 286 (Athlon 2009 MHz, 256 MB)
by Tord Romstad, Marco Costalba, Joona Kiiski Modifications: Dann Corbit

1.00 0:00 +1.97 18...Qxh2 (132)

2.00 0:00 +1.01 18...Qxh2 19.Nb6 Nxb6 20.axb6 h6
21.Rg1 g6 (272)

3.00 0:00 +1.05 18...Qxh2 19.Nb6 Nxb6 20.axb6 h6
21.Rg3 h5 22.Kd1 O-O-O (46.599) 427

4.00 0:00 +1.01 18...Qxh2 19.Nb6 Nxb6 20.axb6 f6
21.exf6 gxf6 22.Rg1 Bc8 (88.301) 434

5.00 0:00 +0.91 18...Qxh2 19.Nb6 h6 20.Rg3 Nc5
21.Nxa8 Bxa8 22.Nf3 Qh1+ 23.Bg1 Ne4 (354.118) 419

6.00 0:01 +1.14++ 18...Qxh2 19.Nb6 h6 20.Rg3 Nc5
21.Nxa8 Bxa8 22.Qe3 Ne4 23.Nf3 Qh1+
24.Rg1 (805.477) 433

7.01 0:03 +1.05 18...Qxh2 19.Nb6 h6 20.Rg4 Nxb6
21.axb6 Qh1+ 22.Rg1 Qe4+ 23.Qe3 Qxe3+
24.Bxe3 Kd7 25.Ke2 Bc6 26.Nxc6 Kxc6 (1.608.430) 441

8.01 0:06 +1.13 18...Qxh2 19.O-O-O Rb8 20.Nb6 Nc5
21.Nf3 Qh3 22.Qe3 Qh6 23.Kb1 Be7 (2.806.910) 440

9.01 0:10 +1.21 18...Qxh2 19.O-O-O Rb8 20.Rgg1 Ba8
21.Nf3 Qh5 22.Qe3 Bc6 23.Nb6 (4.454.902) 438

10.01 0:13 +0.96-- 18...Qxh2 19.O-O-O Rb8 20.Rgg1 Ba8
21.Rh1 Qg2 22.Rdg1 Qe4 23.Nc3 (5.834.076) 441

11.01 0:51 +0.80 18...Qxh2 19.O-O-O h6 20.Nf3 Qh3
21.Rg3 Qh5 22.Kb1 g5 23.Nb6 Rd8
24.Qe3 Bc5 (22.630.954) 439

11.02 3:13 +0.92 18...Qh6 19.f5 Nxe5 20.fxe6 f6
21.Rg1 Qxd2+ 22.Kxd2 g6 23.Be3 Rd8
24.Raf1 Be7 25.Ke2 O-O 26.Nb6 Bb4
27.e7 Bxe7 28.Ne6 d4 29.Bxd4 (88.699.030) 458

12.01 4:32 +0.96 18...Qh6 19.O-O-O Be7 20.Rg2 g6
21.Be3 Qh5 22.Nb6 Rd8 23.Rf1 O-O
24.Nxd7 Rxd7 25.f5 c3 26.Qxc3 (124.181.794) 455

13.01 4:55 +0.69-- 18...Qh6 19.O-O-O Qxh2 20.Rgg1 Bc8
21.Nb6 Rb8 22.Rh1 (134.520.625) 454

14.01 10:43 +0.68 18...Qh6 19.O-O-O Be7 20.Rg2 g6
21.Be3 O-O 22.f5 Qh3 23.fxe6 Nxe5
24.Rg3 Qh5 25.Nb6 Rae8 26.Bh6 Bb4
27.Qg5 (285.355.279) 443

15.01 28:26 +0.71 18...Qh6 19.O-O-O Be7 20.Rg2 g6
21.Nb6 Nxb6 22.axb6 Qh5 23.Kb1 O-O
24.Rh1 a5 25.Rhg1 Rfd8 26.Qd1 Qxd1+
27.Rxd1 Ra6 28.Rgg1 Rxb6 29.Nf5 Rxb2+ (757.180.431) 443

16.01 34:56 +0.38-- 18...Qh6 19.O-O-O g6 20.Be3 Be7
21.f5 Bxg5 22.Bxg5 (925.070.612) 441

17.01 150:15 +0.19 18...Qh6 19.O-O-O Be7 20.Rg3 g6
21.Be3 Qh4 22.Nb6 Nxb6 23.axb6 Rc8
24.Kb1 Bc5 25.Rg5 Qh6 26.Rg3 O-O
27.Nf3 Bxe3 28.Qxe3 Bc6 29.Re1 (4.034.959.285) 447

18.01 415:17 0.00 18...Qh6 19.O-O-O Be7 20.Rg3 g6
21.Be3 Qh4 {Up to this point the PV was following the game}
22.Nb6 Nxb6 23.axb6 Rc8 24.c3 Bc5 25.f5
Bxd4 26.cxd4 Qe7 27.Bg5 c3 28.bxc3 Qa3+
29.Qb2 Qxb2+ 30.Kxb2 Rc6 31.Kc2 Rxb6 (11.024.554.230) 442

best move: Qh5-h6 time: 818:49.235 min n/s: 443.419 nodes: 21.784.830.322

[Event "ICCF Olympiad 15 Final"]
[Site "ICCF"]
[Date "2006.3.30"]
[Round "-"]
[White "Neumann, Joachim"]
[Black "Boger, Raymond"]
[Result "1-0"]
[WhiteElo "2712"]
[BlackElo "2659"]
[Board "2"]
[WhiteTeam "Germany"]
[BlackTeam "Norway"]

1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6
6.Be3 e6 7.f3 b5 8.Qd2 Nbd7 9.g4 Nb6 10.a4 Nc4
11.Bxc4 bxc4 12.a5 Bb7 13.Na4 d5 14.e5 Nd7 15.f4 Qh4+
16.Bf2 Qxg4 17.Rg1 Qh5 18.Rg5 Qh6 19.O-O-O Be7 20.Rg3 g6
21.Be3 Qh4 22.Nf3 Qh5 23.Qg2 Qh6 24.Rh3 Qg7 25.f5 Nxe5
26.Nd4 O-O 27.fxe6 fxe6 28.Nb6 Bd6 29.Nxa8 Rxa8 30.Kb1 Re8
31.Rf1 Nc6 32.Nxc6 Bxc6 33.Bh6 Qe7 34.Qg4 d4 35.Qxd4 Bc5
36.Qg4 Bd5 37.Bg5 Qb7 38.Rf6 Qg7 39.Qh4 Rb8 40.Qf4 Rf8
41.Rh4 Rxf6 42.Bxf6 Qf8 43.Qg5 Bb4 44.Rg4 Bxa5 45.h3 Qf7
46.h4 Bd2 47.Qxd2 Qxf6 48.Rf4 Qe5 49.Qf2 Qb8 50.Kc1 Qd6
51.h5 c3 52.h6 cxb2+ 53.Kxb2 Qb8+ 54.Kc1 Qd6 55.Qd4
1-0

Eelco
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
Top
Uri Blass
Posts: 11152
Joined: Thu Mar 09, 2006 12:37 am
Location: Tel-Aviv Israel

Re: An hard test position(a pawn sacrifice)

Post by Uri Blass »

Here is another correspondence game with the same opening
http://www.iccf-webchess.com/MakeAMove.aspx?id=246988

Uri
Top

Return to “Computer Chess Club: General Topics”