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Subject: Re: Another good underpromotion test position

Author: Steven J. Brann

Date: 17:08:14 07/23/03

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On July 23, 2003 at 15:24:18, Matthew White wrote:

>[D]8/5p1k/6pp/8/q2QB3/2K4P/1p3P2/8 b - - 0 45
>
>From Levin (2331) - IM Donaldson, Western States Open 2003 (analysis)
>The move actually played was 45... Qa1? 46. Bxg6+!! and draw by perpetual check
>Can your engine find the winning 45... b1=N+!! 46. Bxb1 Qa1+ and black enters
>the endgame a pawn up
>
>Every engine that I have tested finds it eventually. However, some do take
>longer than others :).
>
>Matt

CM9000 (custom personality and SS=12) finds b1=N+ in a fraction of a second and
stays with it.

Time	Depth	Score	Positions	Moves
0:00	1/3	-1.27	2728		45...Qa1 46.Kc4 b1=Q 47.Bxb1 Qxb1
0:00	1/4	-1.27	8330		45...Qa1 46.Kc4 b1=Q 47.Bxb1 Qxb1
0:00	1/4	-1.36	9857		45...b1=N+ 46.Bxb1 Qa1+ 47.Kc4
					Qxb1 48.h4 Qf5
0:00	1/5	-1.41	17701		45...b1=N+ 46.Bxb1 Qa1+ 47.Kc4
					Qxb1 48.h4 Qc2+ 49.Kd5 Qf5+ 50.Kc4
0:00	1/6	-1.40	52486		45...b1=N+ 46.Bxb1 Qa1+ 47.Kc4
					Qxb1 48.h4 Qc2+ 49.Kb5 Qf5+ 50.Kb4
					f6
0:00	1/7	-1.37	97738		45...b1=N+ 46.Bxb1 Qa1+ 47.Kd3
					Qxb1+ 48.Ke2 Qf5 49.h4 Qc2+ 50.Ke3
					Qb3+ 51.Kf4 Qe6
0:00	1/8	-1.38	203194		45...b1=N+ 46.Bxb1 Qa1+ 47.Kd3
					Qxb1+ 48.Ke2 Qa2+ 49.Kf3 Qe6 50.Kg2
					Qf5 51.f3 f6
0:01	1/9	-1.44	435497		45...b1=N+ 46.Bxb1 Qa1+ 47.Kc4
					Qxb1 48.h4 Qf1+ 49.Kb3 Qc1 50.Qf6
					Qb1+ 51.Kc4 Qe4+ 52.Kc5
0:02	1/10	-1.46	834626		45...b1=N+ 46.Bxb1 Qa1+ 47.Kc4
					Qxb1 48.h4 Qc2+ 49.Kd5 Kg8 50.Qf6
					Qb3+ 51.Kc5 Qe6 52.Qd8+ Kh7 53.Qd4
0:05	2/11	-1.47	1707913		45...b1=N+ 46.Bxb1 Qa1+ 47.Kd3
					Qxb1+ 48.Ke2 Qf5 49.Qc3 h5 50.Kf1
					g5 51.Kg2 g4 52.h4 Qe4+ 53.Kg1
0:11	3/12	-1.49	3530375		45...b1=N+ 46.Bxb1 Qa1+ 47.Kd3
					Qxb1+ 48.Ke2 Qf5 49.Qc3 h5 50.Kf1
					f6 51.Kg1 Kg7 52.Qb3 Qe5 53.Kf1
0:24	4/13	-1.51	7954742		45...b1=N+ 46.Bxb1 Qa1+ 47.Kd3
					Qxb1+ 48.Ke2 Qf5 49.Qc3 g5 50.Kf1
					Kg6 51.Kg1 h5 52.Qe3 Qe6 53.Qc3 Qe4
0:57	5/14	-1.58	19426667	45...b1=N+ 46.Bxb1 Qa1+ 47.Kd3
					Qxb1+ 48.Ke2 Qb3 49.h4 g5 50.Qe4+
					Kg7 51.Qd4+ Kg8 52.hxg5 Qb5+ 53.Qd3
					Qxg5 54.Qh3 Qb5+ 55.Ke1 Qb1+ 56.Kd2
					Qb4+ 57.Ke2
2:16	6/15	-1.55	46329684	45...b1=N+ 46.Bxb1 Qa1+ 47.Kd3
					Qxb1+ 48.Ke2 Qb3 49.h4 Qe6+ 50.Kd2
					Qf5 51.f4 Qa5+ 52.Kd3 Qa3+ 53.Kd2
					Qe7 54.Qd5 Kg8 55.Qa8+ Kg7 56.Qa1+
					Qf6

Steve



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