Riazantsev-Yandemirov, Moscow op 2008

[jdart]

See http://www.chessgames.com/perl/chessgame?gid=1483824

White played Rd8! here:

[d] 2b1r1kb/p3np1p/1p2p1PB/4P1Q1/5N2/8/P1q2PP1/3R2K1 w - -

Some engines find this quickly but others want to select g7+, which only draws. The winning line is fairly deep.

--Jon

[Albert Silver]

See http://www.chessgames.com/perl/chessgame?gid=1483824

White played Rd8! here:

[d] 2b1r1kb/p3np1p/1p2p1PB/4P1Q1/5N2/8/P1q2PP1/3R2K1 w - -

Some engines find this quickly but others want to select g7+, which only draws. The winning line is fairly deep.

--Jon

Analysis by Rybka WinFinder 2.2 32-bit on Athlon64 2.2GHz:

1.g7 Qxd1+ 2.Kh2 Nf5
= (0.25) Depth: 4 00:00:00
1.g7 Qxd1+ 2.Kh2 Nf5 3.gxh8Q+ Kxh8 4.Qf6+ Kg8
= (0.25) Depth: 5 00:00:00
1.g7 Qxd1+ 2.Kh2 Nf5 3.gxh8Q+ Kxh8 4.Qf6+ Kg8 5.Qg5+ Kh8 6.Qf6+ Kg8 7.Qg5+ Kh8
= (0.25) Depth: 6 00:00:00 7kN
1.g7 Qxd1+ 2.Kh2 Nf5 3.gxh8Q+ Kxh8 4.Qf6+ Kg8 5.Qg5+ Kh8 6.Qf6+ Kg8 7.Qg5+ Kh8
= (0.25) Depth: 7 00:00:00 12kN
1.g7 Qxd1+ 2.Kh2 Nf5 3.gxh8Q+ Kxh8 4.Qf6+ Kg8 5.Qg5+ Kh8 6.Qf6+ Kg8 7.Qg5+ Kh8
= (0.25) Depth: 8 00:00:00 20kN
1.g7 Qxd1+ 2.Kh2 Nf5 3.gxh8Q+ Kxh8 4.Qf6+ Kg8 5.Qg5+ Kh8 6.Qf6+ Kg8 7.Qg5+ Kh8
= (0.25) Depth: 9 00:00:00 35kN
1.g7 Qxd1+ 2.Kh2 Nf5 3.gxh8Q+ Kxh8 4.Qf6+ Kg8 5.Qg5+ Kh8 6.Qf6+ Kg8 7.Qg5+ Kh8
= (0.25) Depth: 10 00:00:01 67kN
1.Rd8
² (0.29) Depth: 10 00:00:02 67kN
1.Rd8
² (0.59) Depth: 10 00:00:02 67kN
1.Rd8 Rxd8 2.g7 Qd1+ 3.Kh2 Nf5 4.gxh8Q+ Kxh8 5.Nh5 f6 6.Bg7+ Kg8
² (0.67) Depth: 10 00:00:02 141kN
1.Rd8 Rxd8 2.g7 Qd1+ 3.Kh2 Nf5 4.gxh8Q+ Kxh8 5.Nh5 f6 6.Bg7+ Kg8 7.Bxf6+ Kf7
± (0.92) Depth: 11 00:00:02 163kN
1.Rd8 Rxd8 2.g7 Qd1+ 3.Kh2 Nf5 4.gxh8Q+ Kxh8 5.Nh5 f6 6.Bg7+ Kg8 7.Bxf6+ Kf7
± (1.01) Depth: 12 00:00:05 311kN
1.Rd8 Rxd8 2.g7 Qd1+ 3.Kh2 Nf5 4.gxh8Q+ Kxh8 5.Nh5 f6 6.Bg7+ Kg8 7.Bxf6+ Kf7
± (0.75) Depth: 13 00:00:08 567kN
1.Rd8 Rxd8 2.g7 Qd1+ 3.Kh2 Nf5 4.gxh8Q+ Kxh8 5.Nh5 f6 6.Bg7+ Kg8 7.Bxf6+ Kf7
± (0.84) Depth: 14 00:00:16 1126kN
1.Rd8 Rxd8 2.g7 Qd1+ 3.Kh2 Nf5 4.gxh8Q+ Kxh8 5.Nh5 f6 6.Bg7+ Kg8 7.Bxf6+ Kf7
± (0.92) Depth: 15 00:00:31 2206kN
1.Rd8 Rxd8 2.g7 Qd1+ 3.Kh2 Nf5 4.gxh8Q+ Kxh8 5.Nh5 f6 6.Bg7+ Kg8 7.Bxf6+ Kf7
± (0.92) Depth: 16 00:01:07 4662kN

(Silver, Private 06.02.2008)

[David Dahlem]

See http://www.chessgames.com/perl/chessgame?gid=1483824

White played Rd8! here:

[d] 2b1r1kb/p3np1p/1p2p1PB/4P1Q1/5N2/8/P1q2PP1/3R2K1 w - -

Some engines find this quickly but others want to select g7+, which only draws. The winning line is fairly deep.

--Jon

Sage finds Rd8 quickly but doesn't give a winning score ...

FEN: 2b1r1kb/p3np1p/1p2p1PB/4P1Q1/5N2/8/P1q2PP1/3R2K1 w - - 0 1

Sage 3.38:
4 00:00 2.465 18.961 -0.94 g6xf7+ Kg8xf7 Rd1d6 Qc2f5
5 00:00 14.419 90.118 -0.44 g6g7
5 00:00 17.404 108.775 0.00 g6g7 Qc2xd1+ Kg1h2 Ne7f5 g7xh8Q+ Kg8xh8 Qg5f6+ Kh8g8 Qf6g5+ Kg8h8
6 00:00 23.533 138.429 0.00 g6g7 Qc2xd1+ Kg1h2 Ne7f5 g7xh8Q+ Kg8xh8 Qg5f6+ Kh8g8 Qf6g5+ Kg8h8
7 00:00 56.643 209.788 0.00 g6g7 Qc2xd1+ Kg1h2 Ne7f5 g7xh8Q+ Kg8xh8 Qg5f6+ Kh8g8 Qf6g5+ Kg8h8
8 00:00 138.237 329.135 0.00 g6g7 Qc2xd1+ Kg1h2 Ne7f5 g7xh8Q+ Kg8xh8 Qg5f6+ Kh8g8 Qf6g5+ Kg8h8
9 00:01 298.146 387.202 0.00 g6g7 Qc2xd1+ Kg1h2 Ne7f5 g7xh8Q+ Kg8xh8 Qg5f6+ Kh8g8 Qf6g5+ Kg8h8
10 00:01 649.590 447.993 0.00 g6g7 Qc2xd1+ Kg1h2 Ne7f5 g7xh8Q+ Kg8xh8 Qg5f6+ Kh8g8 Qf6g5+ Kg8h8
11 00:03 1.490.105 493.412 0.00 g6g7 Qc2xd1+ Kg1h2 Ne7f5 g7xh8Q+ Kg8xh8 Qg5f6+ Kh8g8 Qf6g5+ Kg8h8
11 00:07 3.871.045 490.626 +0.49 Rd1d8 Re8xd8 g6g7 Qc2d1+ Kg1h2 Ne7f5 g7xh8Q+ Kg8xh8 Nf4h5 Rd8g8 Qg5f6+ Rg8g7 Nh5xg7 Kh8g8 Ng7xf5 e6xf5
12 00:10 5.387.816 506.373 +0.34 Rd1d8 Re8xd8 g6g7 Qc2d1+ Kg1h2 Ne7f5 g7xh8Q+ Kg8xh8 Nf4h5 f7f6 Bh6g7+ Kh8g8 Bg7xf6+ Kg8f7 Bf6xd8 Qd1f1 Qg5f6+ Kf7e8 f2f3
13 00:22 12.094.863 528.390 +0.41 Rd1d8 Re8xd8 g6g7 Qc2d1+ Kg1h2 Ne7f5 g7xh8Q+ Kg8xh8 Nf4h5 f7f6 Bh6g7+ Kh8g8 Bg7xf6+ Kg8f7 Bf6xd8 Qd1e1 Nh5f6 Qe1xe5+ f2f4 Qe5a1 Nf6xh7 Qa1xa2
14 00:50 27.300.271 546.005 +0.91 Rd1d8
14 01:04 35.587.258 556.050 +1.04 Rd1d8 Re8xd8 g6g7 Qc2d1+ Kg1h2 Ne7f5 g7xh8Q+ Kg8xh8 Nf4h5 f7f6 Bh6g7+ Kh8g8 Bg7xf6+ Kg8f7 Bf6xd8 Qd1c2 Qg5f6+ Kf7e8 Qf6h8+ Ke8d7 Nh5f6+ Kd7c6 Qh8xh7 Qc2xa2

Regards
Dave

[Ovyron]

ProDeo 1.6b on Athlon 2.1Ghz wastes too much time on gxh7+ (so, it's a matter of move ordering, as Rd8 would have been found in about 33 seconds if it was ordered before gxh7+.) But I think that its finding time is acceptable.

00:00:00.7 -1.80 1 79 gxh7+ Kxh7
00:00:00.7 -0.64 1 152 gxf7+ Kxf7
00:00:00.8 -1.01 2 1183 gxf7+ Kxf7 Rd6 Qxa2
00:00:00.8 -1.42 3 6592 gxf7+ Kxf7 Re1 Qf5 Qh4 Bxe5
00:00:00.8 -1.99 4 47478 gxf7+ Kxf7 Rd6 Ng6 Nxg6 Qxg6 Qf4+ Kg8
00:00:00.9 -2.16 5 110711 gxf7+ Kxf7 Re1 Qf5 Qh4 Kg8 Qg3+ Ng6
00:00:00.9 -2.16 5 135100 g7
00:00:00.9 0.00 5 139356 g7 Qxd1+ Kh2 Nf5 gxh8Q+ Kxh8 Qf6+
00:00:01.0 0.00 6 150310 g7 Qxd1+ Kh2 Nf5 gxh8Q+ Kxh8 Qf6+
00:00:01.1 0.00 7 223082 g7 Qxd1+ Kh2 Nf5 gxh8Q+ Kxh8 Qf6+
00:00:01.2 0.00 8 377835 g7 Qxd1+ Kh2 Nf5 gxh8Q+ Kxh8 Qf6+
00:00:01.4 0.00 9 595903 g7 Qxd1+ Kh2 Nf5
00:00:01.9 0.00 10 1119594 g7 Qxd1+ Kh2 Nf5 gxh8Q+ Kxh8 Qf6+
00:00:03.7 0.00 11 3123400 g7 Qxd1+ Kh2 Nf5 gxh8Q+ Kxh8 Qf6+
00:00:06.7 0.00 12 6641692 g7 Qxd1+ Kh2 Nf5 gxh8Q+ Kxh8 Qf6+
00:00:11.5 0.00 13 12288215 g7 Qxd1+ Kh2 Nf5 gxh8Q+ Kxh8 Qf6+
00:00:23.2 0.00 14 26226314 g7 Qxd1+ Kh2 Nf5 gxh8Q+ Kxh8 Qf6+
00:01:08.1 0.00 14 77278875 Rd8
00:01:18.4 0.72 14 88080863 Rd8 Rxd8 g7 Qd1+ Kh2 Nf5 gxh8Q+

[Terry McCracken]

See http://www.chessgames.com/perl/chessgame?gid=1483824

White played Rd8! here:

[d] 2b1r1kb/p3np1p/1p2p1PB/4P1Q1/5N2/8/P1q2PP1/3R2K1 w - -

Some engines find this quickly but others want to select g7+, which only draws. The winning line is fairly deep.

--Jon

Black's Rd1+ is a blunder.