Author: Heiner Marxen
Date: 13:54:57 10/24/01
Go up one level in this thread
On October 23, 2001 at 14:23:55, Paul wrote:
>On October 23, 2001 at 12:21:10, leonid wrote:
>
>>On October 23, 2001 at 11:03:15, Paul wrote:
>>
>>>On October 23, 2001 at 09:49:55, leonid wrote:
>>>
>>>>[D]NRqQQqRQ/kqrqnrbn/Nq4qQ/1Qn2qQ1/2QrbQ2/3BB3/8/K6Q w - -
>>>>
>>>>Please indicate your result.
>>>>
>>>>Thanks,
>>>>Leonid.
>>>
>>>Hi,
>>
>>Hi!
>>
>>>Pretz (she's a TSCP-clone and proud of it ;)) says this is an easy mate in 10:
:-))
>>What is exactly "TSCP"? You want, probably, say that you looked into some
>>program by doing your own, but if it is so, what exactly?
>
>Sorry Leonid, that remark was for Heiner, see his message from earlier today:
>
>http://www.icdchess.com/forums/1/message.shtml?193869
>
>TSCP is "Tom Kerrigan's Simple Chess Program". It has a basic board structure,
>move generation and alpha-beta search, a (very) small evaluation function and is
>very clearly written and easy to understand (if you can read C).
>
>In short, IMHO it is *the* program to read if you want to start programming one
>yourself. I used the first version of it to start my Pretz project.
>
>I wish Heiner's "Chessmaster clone" remark was true, because that would mean I'd
>know the insides of Chessmaster, boy .. that would be something! I think it's a
>really really (ok ... one more :) really great program!
>
>Except for the fact that my CM6000 doesn't seem to work correctly on Windows XP.
>Installed it just now and tried your last position, the first try took 6
>minutes, I thought: wot? that can't be right? ... and on the further tries it
>just froze. :( Must be doing something wrong, but what?
>
>>Mate is really easy but still you almost reached me on this one. Mine took 3.8
>>sec (can be said 4 sec) to find mate by selective in 10 moves deep.
>
>But I used a p3/1000 and a hashtable for this, sooo ... :)
>
>>It is mate in 10. Verified only 9 moves by brute force, where branching factor
>>was mild.
>
>I checked my solution with Chest later, it's a mate in 10 alright ... I'll leave
>the details to Herr Marxen.
>
>>>00:04 WM10 07 Rxb7+ Qbxb7 Qcxc5+ Qxc5 Qgxc5+ Kxa8 Nxc7+ Qdxc7 Qa5+ Qga6 Qaxa6+
>>>Qa7 Qaxa7+ Qxa7+ Qxa7+ Kxa7 Qhb6+ Ka8 Qa6#
>>
>>Cheers,
>>Leonid.
>
>Groetjes,
>Paul
Well, so I have to provide more detail... After 48 minutes (K7/600, 350MB)
Chest confirms that the above is the shortest and the only solution.
PV: Rxb7+ Qbxb7 Qcxc5+ Qxc5 Qgxc5+ Kxa8 Nxc7+ Qbxc7 Qxc8+ Nxc8 Qa6+ Qxa6+ Qxa6+
Qa7 Qcxc8+ Qxc8 Qxc8+ Qxc8 Rxc8#
Again, there is an interesting spike in the EBF at depth 8:
# 1 0.00s 0kN 0.87 1- 0
# 2 0.01s 0kN 1.00 1- 0
# 3 0.03s [ 3.00] 1kN [ 12.64] 0.95 97- 0
# 4 0.19s [ 6.33] 9kN [ 6.74] 1.03 1048- 0
# 5 0.91s [ 4.79] 39kN [ 4.50] 1.19 5715- 0
# 6 3.66s [ 4.02] 161kN [ 4.11] 1.37 25375- 0
# 7 16.01s [ 4.37] 742kN [ 4.62] 1.60 106210- 0
# 8 266.52s [ 16.65] 15814kN [ 21.32] 1.40 1239680- 1
# 9 1067.19s [ 4.00] 62768kN [ 3.97] 2.16 4669068- 18973
# 10 2872.63s [ 2.69] 167700kN [ 2.67] 2.91 12986453- 4313861
I guess that black exhausted its material to check white, got mated,
and had to search for alternate defensive measures, which helped two
moves deeper.
More detail? Here is the start of the solution tree, 9 plies deep:
Rxb7+ Qbxb7 Qcxc5+ Qxc5 Qgxc5+ Kxa8 Nxc7+ Qbxc7 Qxc8+ ...+5
Kb8 Na6+ ...+3
Qdxc7 Qxb7+ ...+3
Qgb6 Qhxb6+ Kxa8 Nxc7+ ...+3
Qxb6 Qcxb6+ ...+2
Qbb6 Qcxb6+ Qxb6 Qhxb6+ ...+2
Kxa8 Qb8+ ...+1
Rxc5 Qb8+ =*= Qxb8+ ...+1
Kxa8 Nxc7+ Qbxc7 Qa5+ Qa7 Qb8+ ...+4
Qa6 Qhxa6+ ...+2
Qxa5+ Qdxa5+ ...+2
Kb7 Qaa7#
Kb8 Qca7#
Qdxc7 Qxb7+ Bxb7 Qxb7+ ...+3
Qxb7 Qda5+ ...+2
Kxb7 Qfxc7+ ...+1
Kb8 Na6+ Ka8 Qb8+ ...+2
Qgb6 Qhxb6+ Kxa8 Nxc7+ Qbxc7 Q6a6+ ...+2
Qdxc7 Qxb7+ ...+2
Kb8 Qa7#
Qxb6 Qcxb6+ Kxa8 Qb8+ ...+1
Qbb6 Qcxb6+ Qxb6 Qhxb6+ Kxa8 Qb8+ ...+1
Kxa8 Qb8+ Qxb8 Qdxb8#
Rxc5 Qb8+ Qbxb8 Qxb8+ Qxb8 Qxb8#
Qcxb8 Qxb8+ Qxb8 Qbxb8#
Qcxb7 Qxb6+ Qgxb6 Qxb6+ Qxb6 Qb8+ Qxb8 Qxb8+ ...+3
Qbxb6 Qb8+ Qxb8 Qxc5+ Qxc5 Qxc5+ ...+2
Qbb6 Qxb6+ ...+1
Qgb6 Qhxb6+ ...+1
Rxc5 Qfxb8#
-*- Qxb8+ ...+1
Bxb7 Qxb6+ Qxb6 Qxb6+ Kxa8 Nxc7+ Kb8 Na6+ ...+2
Qxc7 Qba6+ ...+2
Kxa8 Nxc7+ Kb8 Na6+ Ka8 Qb8+ ...+1
Qxc7 Qea4+ Na6 Qaxa6+ ...+1
Nxa4 Qca6+ ...+1
Kb8 Qfxc7#
Nxb7 Qxb6+ Qxb6 Qxb6+ Kxa8 Nxc7+ Kb8 Na6+ ...+2
Qxc7 Qba6+ ...+1
Kxa8 Nxc7+ Kb8 Na6+ Ka8 Qb8+ ...+1
Qxc7 Qca6+ Kb8 Qfxc7#
Rxb7 Qbxb6+ Qxb6 Qhxb6+ Kxa8 Qb8+ =*= Qxb8+ ...+1
Rxb6 Qxb6+ Kxa8 Qfb8+ ...+1
Rxb6 Qxb6+ Qxb6 Qxb6+ Kxa8 Qbb8+ ...+1
Kxa8 Qfb8+ Qxb8 Qbxb8#
Kxa8 Qb8+ Qxb8 Qxb8+ Rxb8 Qbxb8#
Rxb8 Qxb8+ Qxb8 Qxb8#
Kxb7 Qxb6+ Qxb6 Qxb6+ Kxa8 Qb8+ Qxb8 Qxb8#
Kxa8 Qb8+ Qxb8 Qxb8#
Kxa8 Rb8+ Ka7 Qxb6+ Qxb6 Qxb6#
Qbxb8 Qxb8+ Qxb8 Qxb8#
Qcxb8 Qxb8+ Qxb8 Qbxb8#
Except at the top level, Chest did not search for duals, i.e. alternate
solutions for white.
Cheers,
Heiner
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