Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Mate in 10 :-) and the aesthetics of EGTBs

Author: John Merlino

Date: 11:26:38 08/11/02

Go up one level in this thread


On August 11, 2002 at 06:49:12, Harald Faber wrote:

>On August 10, 2002 at 21:53:49, John Merlino wrote:
>
>>Here is a position from a game that Slater and I discussed in a different
>>thread:
>>
>>[D]3R4/8/8/8/2K5/6p1/3p1rk1/8 b - - 0 78
>>
>>In that game, Black was obviously using EGTBs and played 78...d1=Q, leading to
>>an EGTB mate in 22 moves (including the promotion). However, the more natural
>>looking move, Kf1, leads to a mate in 14, as Chessmaster 9000 shows on a
>>PIII-733:
>>
>>Time	Depth	Score	Positions	Moves
>>0:00	1/5	-8.88	14450		78...Kf1 79.Kc3 g2 80.Rd4 g1=Q
>>					81.Rxd2 Rxd2 82.Kxd2
>>0:00	2/6	-9.00	26438		78...Kf1 79.Kc3 g2 80.Rxd2 Rxd2
>>					81.Kxd2 g1=Q 82.Kd3 Qc5 83.Ke4 Ke2
>>0:00	3/7	-9.00	74581		78...Kf1 79.Kc3 g2 80.Rxd2 Rxd2
>>					81.Kxd2 g1=Q 82.Kd3 Qc5 83.Ke4 Ke2
>>0:02	4/8	-11.19	264563		78...Kf1 79.Kc3 Ke1 80.Kc4 g2 81.Re8+
>>					Re2 82.Rg8 d1=Q 83.Kc5 Kf1
>>0:05	5/9	-13.17	520117		78...Kf1 79.Kc3 Ke1 80.Kc4 g2 81.Re8+
>>					Re2 82.Rd8 g1=Q 83.Rxd2 Kxd2 84.Kd5
>>0:15	6/10	-13.30	1610302		78...Kf1 79.Kc3 Ke1 80.Kc4 g2 81.Re8+
>>					Re2 82.Rd8 g1=Q 83.Rd5 Qg4+ 84.Kc5
>>					Qc8+ 85.Kb5 d1=Q 86.Rxd1+ Kxd1
>>0:46	7/11	-13.35	4752680		78...Kf1 79.Kc3 Ke1 80.Kc4 g2 81.Re8+
>>					Re2 82.Rd8 g1=Q 83.Rd5 Qg4+ 84.Kc5
>>					Qc8+ 85.Kb5 Qb7+ 86.Kc5 Qc7+ 87.Kb5
>>					d1=Q 88.Rxd1+ Kxd1
>>3:06	8/12	-15.25	19391217	78...Kf1 79.Kc3 Ke1 80.Kc4 g2 81.Re8+
>>					Kf1 82.Rd8 g1=Q 83.Rd4 Qg8+ 84.Kc5
>>					Qg5+ 85.Kc4 Rf4 86.Kb3 Rxd4
>>9:45	9/13	-Mate14	62576834	78...Kf1 79.Kc3 Ke1 80.Kc4 g2 81.Re8+
>>					Re2 82.Rd8 g1=Q 83.Rd6 Qg8+ 84.Kb4
>>					Qb8+ 85.Kc4 Qc7+ 86.Kb5 Re5+ 87.Kb4
>>					Qc5+ 88.Kb3 Re3+ 89.Rd3 Rxd3+ 90.Kb2
>>					Qc1+ 91.Ka2 Ra3#
>>
>>Note that the first capture is 23 ply away, making it very difficult
>>(impossible?) to find it via tablebases. Can anybody else find the mate faster?
>
>As always... YES...
>
>GambitTiger 2 aggr.:
>
>Neue Partie
>3R4/8/8/8/2K5/6p1/3p1rk1/8 b - - 0 1
>
>Analysis by Gambit Tiger 2.0:
>
>1...d2-d1D 2.Td8-d2 Tf2xd2 3.Kc4-b5 Kg2-f2 4.Kb5-c4 Td2-c2+ 5.Kc4-b5 g3-g2
>  -+  (-30.12)   Tiefe: 8   00:00:00  187kN, tb=35
>1...d2-d1D
>  -+  (-31.02)   Tiefe: 9   00:00:00  261kN, tb=47
>1...d2-d1D 2.Td8xd1
>  -+  (-#22)   Tiefe: 9   00:00:00  283kN, tb=63
>1...d2-d1D 2.Td8xd1
>  -+  (-#22)   Tiefe: 10   00:00:02  883kN, tb=261
>1...Tf2-f4+ 2.Kc4-c5 d2-d1D 3.Td8xd1
>  -+  (-#21)   Tiefe: 10   00:00:04  1840kN, tb=425
>1...Tf2-f4+ 2.Kc4-c5 Tf4-f5+ 3.Kc5-c6 d2-d1D 4.Td8xd1
>  -+  (-#20)   Tiefe: 11   00:00:08  3238kN, tb=804
>1...Tf2-f4+ 2.Kc4-c5 Tf4-f5+ 3.Kc5-c6 d2-d1D 4.Td8xd1
>  -+  (-#20)   Tiefe: 12   00:00:19  6777kN, tb=2563
>1...Kg2-f1 2.Td8-d4 g3-g2 3.Td4-d6 g2-g1D 4.Kc4-b5 Tf2-f6 5.Td6xf6+
>  -+  (-#12)   Tiefe: 12   00:00:41  18148kN, tb=4317
>1...Kg2-f1 2.Kc4-c3 g3-g2 3.Td8xd2
>  -+  (-#10)   Tiefe: 13   00:02:25  75601kN, tb=9373
>
>(Faber, Haltern 12.08.2002)
>
>>So, SPEAKING STRICTLY AESTHETICALLY, what do you think of EGTBs when used in
>>game play?
>
>No problem.
>
>>jm
>
>
>What do you say NOW? :-)

I assume that you WERE using tablebases here? If so, then the point was that
CM9000 was NOT using tablebases to find the mate. Additionally, you should
remember to always add 1 to Tiger's mate declarations. So it is really a mate in
11 that Tiger found.

jm



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.