Author: Steffen Jakob
Date: 23:27:12 02/04/01
Go up one level in this thread
On February 03, 2001 at 20:03:33, Eduard Nemeth wrote:
>It is a simple testposition ( my new composition :), but i think it is for
>chess-programs hard! :)
>
>[D]qrk5/1p2Kp2/pBp1pPb1/P1P1P3/8/8/8/8 b - - 0 1
>
>Black win!
Very nice position!
Normally Hossa has no chance to find the solution. Some time ago I worked on an
idea to detect and evaluate such blocked positions. The main idea is to not only
evaluate a position statically but also to consider how the evaluation
progresses from ply to ply. If you already seem to have such a big advantage
like black in Eduards test position than you "should" be able to make this
advantage bigger within "some" plies. If you are not able to do this, then this
is a strong indication for a blocked position. I have written a liitle bit about
this on Hossa's homepage (http://www.jakob.at/steffen/hossa.html).
I even have written some experimental code for this idea and it works partly. It
has some very nasty side effects though, and therefore it's not part of the
standard Hossa. But: if I activate this code then Hossa finds the solution Qa7
after 16 seconds:
depth value time nodes pv
1 +15.82 0.02 3 1... g6e4 2.e7xf7
7/1 +17.33 0.03 15 1... g6h5
<1> +17.33 0.03 17 1... g6h5
2 +17.49 0.03 27 1... g6h5 2.e7d6
<2> +17.49 0.03 41 1... g6h5 2.e7d6
3 +17.70 0.03 85 1... g6h5 2.e7d6 h5f3
<3> +17.70 0.03 189 1... g6h5 2.e7d6 h5f3
? 4 +16.46 0.05 533 1... g6h5 2.b6c7 h5g6 3.c7xb8 c8xb8
? <4> +16.46 0.06 691 1... g6h5 2.b6c7 h5g6 3.c7xb8 c8xb8
5 +16.45 0.07 1019 1... g6h5 2.b6c7 a8a7 3.c7xb8 a7xb8
<5> +16.45 0.13 2349 1... g6h5 2.b6c7 a8a7 3.c7xb8 a7xb8
2/6 +16.16 0.16 3367 1... g6d3 2.e7e8 d3e4 3.e8xf7 c8d7
4.f7g7
<6> +16.16 0.20 4326 1... g6d3 2.e7e8 d3e4 3.e8xf7 c8d7
4.f7g7
! 7 +16.78 0.25 5893 1... g6d3 2.e7e8 d3e4 3.e8xf7 c8d7
4.f7g7 b8g8 5.g7h6
! <7> +16.78 0.36 9796 1... g6d3 2.e7e8 d3e4 3.e8xf7 c8d7
4.f7g7 b8g8 5.g7h6
? 8 +13.49 0.56 19307 1... g6d3 2.e7e8 d3e2 3.e8e7 e2h5
4.b6c7 b6 5.c7d6 b6xa5 6.d6xb8
? <8> +13.49 0.64 22453 1... g6d3 2.e7e8 d3e2 3.e8e7 e2h5
4.b6c7 b6 5.c7d6 b6xa5 6.d6xb8
! 9 +13.58 0.73 27196 1... g6d3 2.e7e8 d3e2 3.e8e7 e2d1
4.e7d6 d1c2 5.b6c7 b6 6.c7xb8 b6xa5
! <9> +13.58 0.89 34857 1... g6d3 2.e7e8 d3e2 3.e8e7 e2d1
4.e7d6 d1c2 5.b6c7 b6 6.c7xb8 b6xa5
? 10 +6.92 1.45 66720 1... g6d3 2.e7e8 d3c2 3.e8e7 c2e4
4.e7e8 a8a7 5.b6xa7 b8a8 6.a7b6
? <10> +6.92 1.69 82593 1... g6d3 2.e7e8 d3c2 3.e8e7 c2e4
4.e7e8 a8a7 5.b6xa7 b8a8 6.a7b6
! 11 +6.90 1.98 100809 1... g6d3 2.e7e8 d3f1 3.e8e7 f1e2
4.e7e8 e2d3
! <11> +6.90 2.71 146194 1... g6d3 2.e7e8 d3f1 3.e8e7 f1e2
4.e7e8 e2d3
! 12 +6.90 3.27 186272 1... g6d3 2.e7e8 d3f1 3.e8e7 f1e2
4.e7e8 e2d3 5.e8e7 d3e4
! <12> +6.90 4.40 265299 1... g6d3 2.e7e8 d3f1 3.e8e7 f1e2
4.e7e8 e2d3 5.e8e7 d3e4
! 13 +6.90 5.58 348430 1... g6d3 2.e7e8 d3e2 3.e8e7 e2f1
4.e7e8 f1c4 5.e8e7 c4e2
!2/13 +7.38 15.98 998322 1... a8a7 2.b6xa7 b5 3.c5xb6 c5
4.e7d6 c4 5.b7 c8xb7 6.a7d4 b8d8
7.d6c5 g6d3 8.d4c3 d8d5 9.c5b4
! <13> +7.38 16.36 1023359 1... a8a7 2.b6xa7 b5 3.c5xb6 c5
4.e7d6 c4 5.b7 c8xb7 6.a7d4 b8d8
7.d6c5 g6d3 8.d4c3 d8d5 9.c5b4
Best wishes,
Steffen.
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