Computer Chess Club Archives

Messages

Subject: Re: Spike-Rybka

Author: Eelco de Groot

Date: 13:07:00 12/28/05

Go up one level in this thread

```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

[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

```