Computer Chess Club Archives




Subject: Re: Spike-Rybka

Author: Vasik Rajlich

Date: 03:05:22 12/29/05

Go up one level in this thread

On December 28, 2005 at 16:07:00, Eelco de Groot wrote:

>Hello Vasik,
>Being just a weak 1300 clubplayer, I think I nevertheless would agree with you
>that White is better and I would not like to have to play with the black pieces
>in this position. The main characteristic of the position seems to me that Black
>has very few plausible moves (even looking superficially) and White has many? If
>you had some sort of static evaluator that could count the number of
>superficially plausible moves somehow, that would give White a headstart here.
>No idea if that could be constructed though in a static eval but with a 1 ply
>search plus qsearch it would be different already? For Black I see only
>plausible moves Qg5, Qh5, Rh6 (backward Rookmoves should maybe get a penalty
>unless they attack something or defend an attacked piece, in this case the Rh6
>defends f6 but the pawn is already well protected. The black bishops can go to
>the backrank but maybe that also should not count, unless there they attack
>something or defend something that needs defending. pawn e6 can go forward to
>e5, but that gives up two very important fields on d5 and f5 for the the White
>Knight on e3. Practically every other Black move loses the piece or creates a
>double pawn after Queen exchange etc.
>I could do some sort of similar calculation for White but I think it is obvious
>that White has many more plausible choices for every single piece. Even if you
>discount moves backward for pieces other than Knights, every piece from White
>can still move. Well, you asked for some "static" evaluation of the position, I
>tried to give one. But I don't know if it is possible to implement such a
>"plausible mobility" evaluator...
> Best Regards,
> Eelco

I think it's a question of the potential of the position. Black is optically
pretty good, but the question is what's next. It's not easy to figure this out,
for humans or computers ..


>[D]8/1b2b1k1/pp1ppp2/nPq5/P1P1P3/2QRNPP1/8/1N2KB1r b - - 0 1
>Pro Deo 1.1 Vulcan sees only an equal position, 0.13 for Black:
>00:00:00.2	-0,43	1	448	axb5 cxb5
>00:00:00.3	0,90	1	450	Rh2
>00:00:00.3	-0,48	2	873	Rh2 Bg2
>00:00:00.3	-0,15	2	1827	Kg8 Kd1
>00:00:00.3	-0,13	2	3583	Qg5 Ng4
>00:00:00.3	0,51	3	5748	Qg5 Kd1 Qxg3
>00:00:00.3	0,51	4	9247	Qg5 Kd1 Qxg3
>00:00:00.3	0,55	5	20287	Qg5 Kd1 Qxg3 Nd2
>00:00:00.4	0,82	6	76759	Qg5 Qc2 Qxg3+ Qf2 Qh3 bxa6
>00:00:00.6	0,38	7	287769	Qg5 g4 Qh4+ Kd1 Qf2 Nd2 Kf8
>00:00:00.7	0,43	8	505674	Qg5 g4 Qh4+ Kd1 Qf2 Nd2 Kf8 Rd4
>00:00:01.7	0,14	9	1492438	Qg5 g4 Qf4 Qd2 Kg8 Qe2 axb5 cxb5 Rh2
>00:00:05.4	0,08	10	5722665	Qg5 g4 Qh4+ Kd1 Qf2 Nd2 Kf8 Qd4 axb5 cxb5
>00:00:13.4	0,08	11	14995976	Qg5 g4 Qf4 Nd2 axb5 cxb5 d5 exd5 Bb4 Qd4 Qg3+ Kd1
>00:00:43.8	0,01	12	50888700	Qg5 g4 Ba8 Kd1 Nb7 Rd2 Nc5 bxa6 Bc6 a7 Qf4 Kc1 Nxa4
>00:01:56.4	0,12	13	138173359	Qg5 g4 Ba8 Qb2
>00:03:58.5	0,10	14	288890040	Qg5 g4 Ba8 Qd2 Nb7 Nd1 Nc5 Qxg5+ fxg5
>00:13:22.2	0,16	15	982663119	Qg5 g4 Ba8 Qc2 Nb7 Qg2 Qh6 g5 fxg5 Ng4 Qh4+ Kd1
>00:47:24.2	0,13	16	3488705002	Qg5 g4 Ba8 Nd1

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