Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Another tactical horizon effect in search reproduced

Author: Uri Blass

Date: 19:40:37 05/06/01

Go up one level in this thread


On May 06, 2001 at 20:33:52, Vincent Diepeveen wrote:

>On May 06, 2001 at 02:28:14, Uri Blass wrote:
>
>>I gave Deep Fritz to analyze similiar number of nodes to Deeper blue and Deep
>>Fritz seems to be clearly better in tactics.
>
>Hi Uri,
>
>Here another tactical horizon effect of Deep Blue and that
>is when the first search line shows up about the f5 move at move 28.
>
>This line shows up in deep blue at move 27 of black at 10 ply.
>
>black timeleft=27:46.40.00
> - = - r r = k =   d3xe4    20    Bd6-c5
> = o = n = o = -   Nf1-e3   21    Ra8-d8
> - q o = - = - o   Nh2-f1   22    g5-g4
> o - = - o - b b   h3xg4    23    Nf6xg4
> - = - = O = - =   f2-f3    24    Ng4xe3
> O O = - N O O -   Nf1xe3   25    Bc5-e7
> - B O = R = B =   Kg1-h1   26    Be7-g5
> R - Q - = - = K   Re1-e2   27    ...
>white timeleft=27:46.40.00
>black to move               type 'help' for command overview
>
>clean
>Clearing all Hashtables...
>anal
>Analysis mode is on
>Process 1: engineflags=256 msk=1
>process 0: engineflags = 256 denktime=10000000 maxtime=10000000
>White can win here 0 worth of material
>Black can win here 0 worth of material
>00:00 0 0 7 (0) 1 -0.15 Bg5xe3 Qc1xe3
>00:00 0 0 13 (0) 1 0.64 Re8-e7
>00:00 0 0 14 (0) 1 0.84 Qb6-c5
>00:00 0 0 17 (0) 1 0.88 Nd7-f6
>00:00 0 0 18 (0) 1 1.01 Nd7-c5
>00:00 0 0 19 (0) 1 1.04 Bh5-g6
>00:00 0 0 33 (0) 1 1.08 Kg8-h7
>00:00 0 0 36 (0) 1 1.13 Kg8-f8
>00:00 0 0 102 (0) 2 0.93 Kg8-f8 Kh1-h2
>00:00 0 0 379 (0) 3 1.20 Kg8-f8 Kh1-h2 Bh5-g6
>00:00 0 0 1988 (391) 4 0.83 Kg8-f8 Kh1-g1 a5-a4 b3xa4
>++ g8-h7
>00:00 0 0 3025 (981) 4 0.87 Kg8-h7 Kh1-g1 Re8-g8 Kg1-f2
>++ d7-c5
>00:00 0 0 7015 (2310) 4 1.09 Nd7-c5 Re2-e1 Kg8-f8 a3-a4
>++ a5-a4
>00:00 0 0 9443 (2991) 4 1.13 a5-a4 g3-g4 Qb6-a6 Qc1-f1 Bh5-g6
>00:00 0 0 16154 (3362) 5 0.92 a5-a4 Qc1-e1 Bh5xf3 Ne3-c4 Bf3xg2 Kh1xg2
>++ g8-h7
>00:00 0 0 26742 (8032) 5 1.03 Kg8-h7 Qc1-g1 Qb6-a6 Ne3-c4 b7-b5
>++ g8-f8
>00:00 0 0 31308 (8497) 5 1.07 Kg8-f8 Qc1-g1 Qb6-a6 Ne3-c4 b7-b5
>++ d7-f6
>00:01 0 0 42949 (11481) 5 1.13 Nd7-f6 Re2-e1 Kg8-f8 f3-f4 e5xf4 g3xf4
>00:02 0 0 76128 (16961) 6 0.18 Nd7-f6 Qc1-e1 Bg5xe3 Re2xe3 Kg8-f8 Kh1-g1
>++ g8-f8
>00:02 0 0 98174 (24532) 6 0.62 Kg8-f8 Qc1-e1 a5-a4 Ne3-c4 Qb6-c5 Bb2-c3 a4xb3 c2
>xb3
>++ a5-a4
>00:03 0 0 142640 (40777) 6 0.69 a5-a4 Qc1-e1 a4xb3 Ne3-f5 Kg8-f8 Qe1-b4 Qb6xb4 a
>3xb4
>00:06 0 0 281030 (55413) 7 0.92 a5-a4 Qc1-e1 a4xb3 Ne3-c4 Qb6-c7 c2xb3 Nd7-c5
>00:10 0 0 544013 (91108) 8 0.70 a5-a4 Qc1-e1 a4xb3 Ne3-c4 Qb6-c7 c2xb3 Nd7-c5 Qe
>1-b4
>00:28 0 0 1753700 (112361) 9 0.89 a5-a4 Qc1-e1 a4xb3 Ne3-c4 Qb6-c7 c2xb3 Nd7-c5
>Qe1-a5 Qc7-e7
>00:48 0 0 3077596 (152700) 10 0.80 a5-a4 Qc1-e1 a4xb3 Ne3-c4 Qb6-c7 c2xb3 Nd7-c5
> Qe1-a5 Qc7xa5 Nc4xa5
>04:12 0 0 17109023 (1591321) 11 0.68 a5-a4 b3-b4 f7-f5 e4xf5 e5-e4 f3-f4 Bg5xf4
>Re2-e1 Bf4xg3 Ne3-c4 Bh5-d1
>09:29 0 0 38492751 (3065091) 12 0.68 a5-a4 b3-b4 f7-f5 e4xf5 e5-e4 f3-f4 Bg5xf4
>Re2-e1 Bf4xg3 Ne3-c4 Bh5-d1
>
>So at 11 ply diep shows same mainline. Now this version of diep has not
>much recapture extensions. I threw those out. Took too many nodes in
>average middlegame to extend most recaptures.
>
>---------------------------------------
>--> re1e2 <--
>---------------------------------------
> -34  T=21
>Pa5a4 pb3b4 Pc6c5 qd2e2 Bg5e3n qe2e3B Pc5b4p bb2c1 Pb4a3p pg3g4 Bh5g6 ra1a3P
>Qb6e3q
> 3(4) -9  T=0
>Pa5a4 pb3a4P Nd7c5
> 4(5) -9  T=0
>Pa5a4 pb3a4P Nd7c5
> 5(5)[a4](-3) -3  T=0
>Pa5a4 pb3a4P Nd7c5
> 6(5)[a4](-26)[Qc5](-25) -25  T=0
>Qb6c5 qc1g1 Qc5b5
> 7(5) #[Qc5](-41)##########################[a4](-8)####### -8  T=3
>Pa5a4 qc1e1 Pa4b3p ne3c4 Qb6c7 pc2b3P
> 8(6)<ch> 's 60'
> #[a4](7)################################## 7  T=8
>Pa5a4 pg3g4 Bh5g6 qc1e1 Pa4b3p ne3c4 Qb6c7 pc2b3P Nd7c5
> 9(6) #[a4](15)################################## 15  T=39
>Pa5a4 pg3g4 Bh5g6 pb3b4 Ph6h5 pg4h5P Bg6h5p qc1e1 Bg5f4 ne3f5
>10(6) #[a4](-15)[a4](-15) -15v T=112
>Pa5a4 pb3b4 Pf7f5 pe4f5P Pe5e4 pf3f4 Bg5f4p pg3f4B Bh5e2r qc1d2 Be2f3 ra1g1
>10(6) #[a4](-20)[TIMEOUT][et3  946 sec]################################## -20
>T=195
>Pa5a4 pb3b4 Pf7f5 pe4f5P Pe5e4 pf3f4 Bh5e2r pf4g5B Nd7e5 pg5g6 Qb6c7 qc1b1 Kg8g7
>pg3g4 Be2f3
>---------------------------------------
>-->  27. ..   a4 <-- 13/55:48
>---------------------------------------
>
>As you see Deep Blue gets it 1 ply sooner as DIEP. It gets it at 10 ply
>versus DIEP 11 ply.
>
>This amazing similarity in mainlines i already saw directly when i added
>loads of what Hsu calls dangerous extensions.
>
>Of course DIEP runs on a PC and it's 2001 now, so i don't want my search
>to completely die because of extensions. So i limit them bigtime all.
>
>So diep needs 1 ply extra usual as Deep Blue to get the same mainlines,
>though usual it's the same.
>
>This mainline is so important because it shows the tactical horizon effect
>a4 b4 f5!? from black.
>
>28..f5 is getting into the lost position as the rest is a forced win for
>white.

I believe that the losing mistake of black is only later.
I believe that 33...Qb5 was a wrong move and Deep Fritz suggets 33...Rd6 with
evaluation of 0.00 after some hours
see http://www.icdchess.com/forums/1/message.shtml?167877

Uri



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.