Censor in the Rybka forum

Zherkovv · Post by **Zherkovv** » Mon Aug 02, 2010 8:12 am

This post was deleted in the Rybka forum.

Rybka Forum 29-07-2010 ----- Test Positions ---- "Zugzwang with a capital Z"

By stephanie Date 2010-07-30 02:05 H**d*n* 1.03a Finds rb1 in 46 seconds on my slow laptop:

New game
1Q6/8/8/2pK3p/8/5N1q/1P4pp/5Rbk w - - 0 1

Start<>EndLookup

Analysis by Houdini 1.03a x64 4_CPU:

1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rc1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Nxh2 Kxh2 9.Rc2 Bb6 10.Ke4 Kg3 11.Rxg2+ Kxg2 12.Kd3 Bc7 13.Kc2 Kh1 14.c4 Bb6
= (0.03) Depth: 6/29 00:00:00 1kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rc1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Nxh2 Kxh2 9.Rc2 Bb6 10.Ke4 Kg3 11.Rxg2+ Kxg2 12.Kd3 Bc7 13.Kc2 Kh1 14.c4 Bb6
= (0.03) Depth: 7/29 00:00:00 1kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rc1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Nxh2 Kxh2 9.Rc2 Bb6 10.Ke4 Kg3 11.Rxg2+ Kxg2 12.Kd3 Bc7 13.Kc2 Kh1 14.c4 Bb6
= (0.03) Depth: 8/29 00:00:00 1kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rc1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Nxh2 Kxh2 9.Rc2 Bb6 10.Ke4 Kg3 11.Rxg2+ Kxg2 12.Kd3 Bc7 13.Kc2 Kh1 14.c4 Bb6
= (0.03) Depth: 9/29 00:00:00 1kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rc1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Nxh2 Kxh2 9.Rc2 Bb6 10.Rxg2+ Kxg2 11.Ke4 Kh3 12.Kf3 Ba5 13.Ke4 Bxc3
= (0.00) Depth: 10/29 00:00:00 2kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rc1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Nxh2 Kxh2 9.Rc2 Bb6 10.Ke4 Kg3 11.Rxg2+ Kxg2 12.Kd3 Bc7 13.Kc2 Kh1 14.c4 Bb6
= (0.03) Depth: 11/29 00:00:00 2kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rc1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Nxh2 Kxh2 9.Rc2 Bb6 10.Ke4 Kg3 11.Rxg2+ Kxg2 12.Kd3 Kh3 13.Kc2 Ba5 14.Kb3 Bxc3
= (0.00) Depth: 12/31 00:00:00 11kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rc1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Nxh2 Kxh2 9.Rc2 Bb6 10.Ke4 Kg3 11.Rxg2+ Kxg2 12.Kd3 Kh3 13.Kc2 Ba5 14.Kb3 Bxc3
= (0.00) Depth: 13/31 00:00:00 28kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rc1 c3 6.b4 c2 7.b5 Qe5+ 8.Kxe5 h2 9.Nxh2 Kxh2 10.Rxc2 Bb6 11.Kf4 Kh1 12.Rxg2 Kxg2 13.Kg4 Be3 14.Kh5 Bb6
= (0.03) Depth: 14/35 00:00:00 188kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rc1 c3 6.b4 c2 7.b5 Qe5+ 8.Kxe5 h2 9.Nxh2 Kxh2 10.Rxc2 Bb6 11.Kf4 Kh1 12.Rc1+ Kh2 13.Kf3 g1Q 14.Rxg1 Bxg1 15.Ke2 Bc5 16.Kd3 Bf2 17.Kc2 Bg3 18.Kb3
= (0.03) Depth: 15/39 00:00:00 303kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rc1 c3 6.b4 c2 7.b5 Qe5+ 8.Kxe5 h2 9.Nxh2 Kxh2 10.Rxc2 Bb6 11.Kf4 Kh1 12.Rc1+ Kh2 13.Kf3 g1Q 14.Rxg1 Bxg1 15.Ke2 Bc5 16.Kd3 Bf2 17.Kc2 Be3 18.Kb3 Kg3 19.Kb2 Ba7 20.Kb3 Bb8 21.Ka4
= (0.03) Depth: 16/39 00:00:00 447kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rc1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Nxh2 Kxh2 9.Kd5 Bf2 10.c4 Be3 11.Ra1 Bb6 12.c5 Bxc5 13.Kxc5 g1Q+ 14.Rxg1 Kxg1 15.Kc6 Kh1 16.Kb7 Kg1
= (0.03) Depth: 17/42 00:00:00 1033kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Bxg1 11.Kd5 Kg2 12.c4 Kg3 13.c5 Bxc5 14.Kxc5 Kg2 15.Kc6 h1Q 16.Rxh1 Kxh1 17.Kb6 Kg1 18.Kb7 Kf2 19.Ka8 Ke2
= (0.03) Depth: 18/42 00:00:00 2276kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Kxg1 11.Kd5 Bf2 12.Rxh2 Kxh2 13.Ke4 Kg3 14.c4 Kg2 15.Kd3 Kf3 16.Kc2 Ke4 17.c5 Bxc5
= (0.00) Depth: 19/42 00:00:01 4019kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Kxg1 11.Kd5 Bf2 12.Rxh2 Kxh2 13.Ke4 Kg3 14.c4 Kg2 15.Kd3 Kf3 16.Kc3 Kf4 17.c5 Bxc5
= (0.00) Depth: 20/42 00:00:01 5044kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Kxg1 11.Kd5 Bf2 12.Rxh2 Kxh2 13.Ke4 Kg3 14.c4 Kg2 15.Kd3 Kf3 16.Kc3 Kf4 17.c5 Bxc5
= (0.00) Depth: 21/42 00:00:02 6391kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Kxg1 11.Kd5 Bf2 12.Rxh2 Kxh2 13.Ke4 Kg3 14.c4 Kg2 15.Kd3 Kf3 16.Kc3 Kf4 17.c5 Bxc5
= (0.00) Depth: 22/62 00:00:04 15538kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Kxg1 11.Kd5 Bf2 12.Rxh2 Kxh2 13.Ke4 Kg3 14.c4 Kg2 15.Kd3 Kf3 16.Kc3 Kf4 17.Kb3 Bb6 18.c5 Bxc5
= (0.00) Depth: 23/62 00:00:06 19759kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Kxg1 11.Kd5 Bf2 12.Rxh2 Kxh2 13.Ke4 Kg3 14.c4 Kg2 15.Kd3 Kf3 16.Kc3 Ba7 17.Kb4 Ke4 18.c5 Bxc5+
= (0.00) Depth: 24/62 00:00:08 26526kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Kxg1 11.Kd5 Bf2 12.Rxh2 Kxh2 13.Ke4 Kg3 14.c4 Kg2 15.Kd3 Kf3 16.Kc3 Bc5 17.Kb3 Bd4 18.c5 Bxc5
= (0.00) Depth: 25/62 00:00:11 37301kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Kxg1 11.Kd5 Bf2 12.Rxh2 Kxh2 13.Ke4 Kg3 14.c4 Kg2 15.Kd3 Kf3 16.Kc3 Bc5 17.Kd2 Bb6 18.c5 Bxc5
= (0.05 !) Depth: 26/62 00:00:17 58359kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Kxg1 11.Kd5 Bf2 12.Rxh2 Kxh2 13.Ke4 Kg3 14.c4 Kg2 15.Kd3 Kf3 16.Kc3 Bc5 17.Kd2 Bb6 18.c5 Bxc5
= (0.15 !) Depth: 26/62 00:00:17 59231kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Kxg1 11.Kd5 Bf2 12.Rxh2 Kxh2 13.Ke4 Kg3 14.c4 Kg2 15.Kd3 Kf3 16.Kc3 Bc5 17.Kd2 Bb6 18.c5 Bxc5
+/= (0.38 !) Depth: 26/62 00:00:18 60271kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Kxg1 11.Kd5 Bf2 12.Rxh2 Kxh2 13.Ke4 Kg3 14.c4 Kg2 15.Kd3 Kf3 16.Kc3 Bc5 17.Kd2 Bb6 18.c5 Bxc5
+/- (1.20 !) Depth: 26/62 00:00:20 66961kN
1.Qxh2+ Qxh2 2.Ra1 h4 3.Ke4 c4 4.Re1 h3 5.Rb1 c3 6.bxc3 Qe5+ 7.Kxe5 h2 8.Rb8 Bc5 9.Rh8 g1Q 10.Nxg1 Kxg1 11.Kd5 Bf2 12.Rxh2 Kxh2 13.Ke4 Kg3 14.c4 Kg2 15.Kd3 Kf3 16.Kc3 Bc5 17.Kd2 Bb6 18.c5 Bxc5
+- (4.36 !) Depth: 26/62 00:00:26 86521kN
1.Qxh2+ Qxh2 2.Rb1 c4 3.Kc6 h4 4.Kb7 h3 5.Ka8 c3 6.bxc3 Qb8+ 7.Rxb8 Bf2 8.Rh8 g1N 9.Nxg1 Kxg1 10.Rxh3 Kg2 11.Rh8 Bc5 12.Kb7 Kf3 13.Kc6 Bg1 14.Re8 Kf4 15.c4 Kf5 16.c5 Kf6 17.Kd5 Kf7 18.Re5 Kf6 19.c6 Bb6 20.Kd6 Bd8 21.Re8 Ba5 22.c7 Bxc7+ 23.Kxc7 Kf5 24.Kd6 Kf4 25.Kd5 Kf3 26.Rf8+ Ke2 27.Ke4 Kd2
+- (6.19) Depth: 26/62 00:00:38 134mN
1.Qxh2+ Qxh2 2.Rb1 c4 3.Kc6 h4 4.Kb7 h3 5.Ka8 c3 6.bxc3 Qb8+ 7.Rxb8 Bf2 8.Rh8 g1N 9.Nxg1 Kxg1 10.Rxh3 Kg2 11.Rh8 Bc5 12.Kb7 Kf3 13.Kc6 Bg1 14.Re8 Kf4 15.c4 Kf5 16.c5 Bh2 17.Kd5 Bc7 18.c6 Ba5 19.Re7 Kf4 20.c7 Bxc7 21.Rxc7 Ke3 22.Rf7 Kd3 23.Rg7 Ke3 24.Re7+ Kd3 25.Re6 Kc3 26.Re7 Kd3 27.Re6
+- (6.36) Depth: 27/62 00:00:47 168mN

(, Microsoft 29.07.2010)

This engine seems to understand Zugzwang, while matching the strength of Rybka 4. Quite amazing really.

Cubeman · Post by **Cubeman** » Mon Aug 02, 2010 12:04 pm

Amazing result to see all this at the root position, the manoevre Kc6-Kb7-Ka8 is cute and the only way to win.Other engines even after analysing position after 2.Rb1 c4 still can't see the King walk.

Robert Houdart · Post by **Robert Houdart** » Mon Aug 02, 2010 5:30 pm

Zherkovv wrote:This post was deleted in the Rybka forum.

1Q6/8/8/2pK3p/8/5N1q/1P4pp/5Rbk w - - 0 1

The improved zugzwang detection is a feature of Houdini 1.03, previous versions couldn't solve this position either (like Rybka 4 and most of the other top engines).

Robert

benstoker · Post by **benstoker** » Mon Aug 02, 2010 6:17 pm

Robert Houdart wrote:
Zherkovv wrote:This post was deleted in the Rybka forum.

1Q6/8/8/2pK3p/8/5N1q/1P4pp/5Rbk w - - 0 1
The improved zugzwang detection is a feature of Houdini 1.03, previous versions couldn't solve this position either (like Rybka 4 and most of the other top engines).

Robert

And didn't this feature come straight from the very recent addition of zugzwang detection to IvanHoe? I think they added it in in version 53.

Or it your zugzwang detection something you created personally for Houdini?

Robert Houdart · Post by **Robert Houdart** » Mon Aug 02, 2010 6:56 pm

benstoker wrote:And didn't this feature come straight from the very recent addition of zugzwang detection to IvanHoe? I think they added it in in version 53.

Or it your zugzwang detection something you created personally for Houdini?

Please check the chronology:
- Houdini 1.03 was released July 15, and I mentioned the improved zugzwang detection in a thread on Talkchess.
- Two days later, on July 17, the Ivanhoe 53 sources are released with an attempt at zugzwang detection.

And as you can probably find out by comparing a number of positions, the zugzwang detection in Houdini is far more sophisticated than what I see in the Ivanhoe 53 source.

Thanks for asking,
Robert

benstoker · Post by **benstoker** » Mon Aug 02, 2010 7:30 pm

Robert Houdart wrote:
benstoker wrote:And didn't this feature come straight from the very recent addition of zugzwang detection to IvanHoe? I think they added it in in version 53.

Or it your zugzwang detection something you created personally for Houdini?
Please check the chronology:
- Houdini 1.03 was released July 15, and I mentioned the improved zugzwang detection in a thread on Talkchess.
- Two days later, on July 17, the Ivanhoe 53 sources are released with an attempt at zugzwang detection.

And as you can probably find out by comparing a number of positions, the zugzwang detection in Houdini is far more sophisticated than what I see in the Ivanhoe 53 source.

Thanks for asking,
Robert

Of course there's no way to tell if your zz code is far more sophisticated by looking at the source code. Don't even know why you'd say that.

In any event, here's IvanHoe 53's detection of this zz position after reaching depth 25:

Code: Select all

info multipv 1 time 68978 nodes 271985657 nps 3943000 score cp 463 depth 25 pv b8h2 h3h2 f1b1 c5c4 d5c6 h5h4 c6b7 h4h3 b7a8 c4c3 b2c3 h2b8 b1b8 g1f2 b8h8 g2g1q f3g1 h1g1 h8h3 g1g2 h3h8 g2g3 a8b7 g3g4 c3c4 g4g5 h8g8 g5h6 b7c6 f2e1 g8g2 h6h5 c4c5 h5h4 c6d5 h4h3

Since you say your zz detection is more sophisticated, can you provide some fen positions in order to show this?

benstoker · Post by **benstoker** » Mon Aug 02, 2010 7:53 pm

Robert Houdart wrote:
benstoker wrote:And didn't this feature come straight from the very recent addition of zugzwang detection to IvanHoe? I think they added it in in version 53.

Or it your zugzwang detection something you created personally for Houdini?
Please check the chronology:
- Houdini 1.03 was released July 15, and I mentioned the improved zugzwang detection in a thread on Talkchess.
- Two days later, on July 17, the Ivanhoe 53 sources are released with an attempt at zugzwang detection.

And as you can probably find out by comparing a number of positions, the zugzwang detection in Houdini is far more sophisticated than what I see in the Ivanhoe 53 source.

Thanks for asking,
Robert

Followup to previous post:

Looks like ih53 finds the zz in about 18.89 seconds at depth 23; 73877K nodes (74mN) (on my old dual core)

Code: Select all

[IvanHoe-Beta version 999953] 23:+3.48} 1.Qxh2+ Qxh2 2.Rb1 c4 3.Kc6 h4 4.Kb7 h3 5.Ka8 c3 6.bxc3 Qb8+ 7.Rxb8 Bf2 8.Rh8 g1=N 9.Nxg1 Kxg1 10.Rxh3 Kg2 11.Rh8 Kg3 12.Kb7 Kg4 13.c4 Kg5 14.Rg8+ Kh6 15.Kc6 Kh7 16.Rf8 Bd4 17.c5 Kg6

All of which makes me wonder, what does zz detection do to ELO? I can't imagine that it adds a whole lot.

Robert Houdart · Post by **Robert Houdart** » Mon Aug 02, 2010 8:44 pm

benstoker wrote:All of which makes me wonder, what does zz detection do to ELO? I can't imagine that it adds a whole lot.

It doesn't really add strength, the very small performance improvement is probably offset by the very small cost.
But it's a fun feature to have.

benstoker wrote:Since you say your zz detection is more sophisticated, can you provide some fen positions in order to show this?

Two examples:
1) Mate in 9
3Q4/3p4/P2p4/N2b4/8/4P3/5p1p/5Kbk w - - 0 1
Houdini 1.03a finds the mate in 9 at depth 17:

17/42 00:01,462 1.853.806 1.533.000 +M9 1.Qa8 Bxa8 2.Nb7 d5 3.Nd6 Bc6 4.a7 d4 5.e4 Bb7 6.a8Q Ba6+ 7.Qxa6 d3 8.e5 d2 9.Qb7+

2) Mate in 20
5q1k/5P1p/Q7/5n1p/6P1/7K/8/8 w - - 0 1
Houdini 1.03a finds a mate at depth 23, and the correct mate in 20 at depth 31:

23/58 00:08,914 24.521.504 2.835.000 +M23 1.Qa1+ Ng7 2.Qf6 Qa3+ 3.Kh4 Qf8 4.Kg5 hxg4 5.Kh4 g3 6.Kh3 Qc8+ 7.Kxg3 Qb8+ 8.Kg2 Qa8+ 9.Kg1 Qf8 10.Kf1 Qxf7 11.Qxf7 h6 12.Kg2 Ne8 13.Qxe8+ Kg7 14.Qe7+ Kg6 15.Qe5 Kf7 16.Kg3 Kg8 17.Qf6 Kh7 18.Qf7+ Kh8 19.Qe7 Kg8 20.Kh4 Kh8 21.Kh5 Kg8 22.Kg6 h5 23.Qd8+
31/61 00:15,624 49.188.032 3.203.000 +M20 1.Qa1+ Ng7 2.Qf6 Qa3+ 3.Kh4 Qf8 4.Kg5 hxg4 5.Kh4 g3 6.Kh3 Qc8+ 7.Kxg3 Qb8+ 8.Kg2 Qa8+ 9.Kg1 Qf8 10.Kf1 Qxf7 11.Qxf7 h6 12.Kg2 Kh7 13.Kg3 h5 14.Kh4 Kh6 15.Qf6+ Kh7 16.Kg5 Nf5 17.Qxf5+ Kg7 18.Kxh5 Kg8 19.Kg6 Kh8 20.Qf8+

What are your findings with Ivanhoe-53 or any other top engine?

Robert

benstoker · Post by **benstoker** » Mon Aug 02, 2010 10:04 pm

Robert Houdart wrote:
benstoker wrote:All of which makes me wonder, what does zz detection do to ELO? I can't imagine that it adds a whole lot.
It doesn't really add strength, the very small performance improvement is probably offset by the very small cost.
But it's a fun feature to have.

benstoker wrote:Since you say your zz detection is more sophisticated, can you provide some fen positions in order to show this?
Two examples:
1) Mate in 9
3Q4/3p4/P2p4/N2b4/8/4P3/5p1p/5Kbk w - - 0 1
Houdini 1.03a finds the mate in 9 at depth 17:

17/42 00:01,462 1.853.806 1.533.000 +M9 1.Qa8 Bxa8 2.Nb7 d5 3.Nd6 Bc6 4.a7 d4 5.e4 Bb7 6.a8Q Ba6+ 7.Qxa6 d3 8.e5 d2 9.Qb7+

For the above, IH 53 finds M9 at depth 18 in 3.02 sec on my box.
IH 54 (no zz detection code) still can't get it after 107 sec at depth 27: PV: +0.32 1. Qf8 Be4 ...

2) Mate in 20
5q1k/5P1p/Q7/5n1p/6P1/7K/8/8 w - - 0 1
Houdini 1.03a finds a mate at depth 23, and the correct mate in 20 at depth 31:

23/58 00:08,914 24.521.504 2.835.000 +M23 1.Qa1+ Ng7 2.Qf6 Qa3+ 3.Kh4 Qf8 4.Kg5 hxg4 5.Kh4 g3 6.Kh3 Qc8+ 7.Kxg3 Qb8+ 8.Kg2 Qa8+ 9.Kg1 Qf8 10.Kf1 Qxf7 11.Qxf7 h6 12.Kg2 Ne8 13.Qxe8+ Kg7 14.Qe7+ Kg6 15.Qe5 Kf7 16.Kg3 Kg8 17.Qf6 Kh7 18.Qf7+ Kh8 19.Qe7 Kg8 20.Kh4 Kh8 21.Kh5 Kg8 22.Kg6 h5 23.Qd8+
31/61 00:15,624 49.188.032 3.203.000 +M20 1.Qa1+ Ng7 2.Qf6 Qa3+ 3.Kh4 Qf8 4.Kg5 hxg4 5.Kh4 g3 6.Kh3 Qc8+ 7.Kxg3 Qb8+ 8.Kg2 Qa8+ 9.Kg1 Qf8 10.Kf1 Qxf7 11.Qxf7 h6 12.Kg2 Kh7 13.Kg3 h5 14.Kh4 Kh6 15.Qf6+ Kh7 16.Kg5 Nf5 17.Qxf5+ Kg7 18.Kxh5 Kg8 19.Kg6 Kh8 20.Qf8+

What are your findings with Ivanhoe-53 or any other top engine?

Robert

For this one, IH53 says M23 at depth 24, which takes 84 sec on my box. Then, the pv jumps back to +11.69 at depth 25. Then, at depth 26, a +327; then at 30, back to M24; then at 31, M26. Kinda weird to me to first announce M23 and then later a M26. Also, I forget what +327 means -- but, I know that's the max score. (BTW, no tablebases, of course)

IH54 (w/o zz) appears stuck at 1. Qxf7 at depth 36 and 615mN, score=0.00, 127 sec.

stockfish 1.8 hits 1. Qa1+ at depth 33, 174mN, score +327 (but not a mate score); maybe it would find a mate score if I let it run longer. But, it apparently has zz detection.

Robert Houdart · Post by **Robert Houdart** » Mon Aug 02, 2010 10:40 pm

As I was impressed by the results you reported (quite unexpected for me), I downloaded the "IvanHoe999953.exe" version from the ChessLogik site.
It cannot solve any of the previously mentioned positions. I've also tried "IvanHoe999952a.exe" from the same web site, same negative results.

Below the results I obtain with IvanHoe999952a.exe after 30 to 60 seconds in each position:

Position 1: 1Q6/8/8/2pK3p/8/5N1q/1P4pp/5Rbk w - - 0 1
29 00:28,423 59.130.699 2.130.000 +0,05 1.Qxh2+ Qxh2 2.Rc1 h4 3.Ke4 c4 4.Rd1 c3 5.bxc3 h3 6.Rc1 Qe5+ 7.Kxe5 h2 8.Rc2 Bb6 9.Ke4 g1Q 10.Rxh2+ Qxh2 11.Nxh2 Kxh2 12.Kd5 Kg2 13.c4 Bf2 14.Kd6 Kf3 15.Kd7 Ba7 16.Kc7 Bd4 17.Kb7 Ke3 18.Kc6 Ke4 19.c5 Kf3 20.Kd5 Bxc5 21.Kc4 Bf2

Position 2: 3Q4/3p4/P2p4/N2b4/8/4P3/5p1p/5Kbk w - - 0 1
23 00:31,949 56.383.647 1.802.000 +0,28 1.Qf6 Be4 2.Qxf2 Bd3+ 3.Qe2 Bxe2+ 4.Kxe2 Kg2 5.a7 h1Q 6.a8Q+ d5 7.Qxd5+ Kh2 8.Qh5+ Kg2 9.Qg4+ Kh2 10.Qf4+ Kh3 11.Qh6+ Kg2 12.Qg7+ Kh2 13.Qh7+ Kg2 14.Qe4+ Kh2 15.Qe5+ Kh3 16.Qf5+ Kg3 17.Nc4 Qg2+ 18.Kd3 Qf3 19.Qg5+ Kf2 20.Qf4 Kg2 21.Qd6 Qf5+ 22.Kd4 Qg4+ 23.Kc3 Qe6 24.Qd4 d5 25.Qg7+ Kf3

Position 3: 5q1k/5P1p/Q7/5n1p/6P1/7K/8/8 w - - 0 1
29 00:59,124 121.196.546 2.073.000 0,00 1.gxf5 Qxf7 2.Qa1+ Kg8 3.Qe5 Kf8 4.f6 Qd7+ 5.Kg3 Qg4+ 6.Kf2 Qb4 7.Qxh5 Qb2+ 8.Kg3 Qxf6 9.Qxh7 Qc3+ 10.Kg2 Qd2+ 11.Kh3 Qc3+ 12.Kh4 Qc4+ 13.Kg5 Qc1+ 14.Kg4 Qd1+ 15.Kf4 Qc1+ 16.Ke5 Qa1+ 17.Kf4 Qc1+

Is there something wrong with the KLO compiles on the ChessLogik site?

Robert

OpenChess

OpenChess

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