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Subject: Re: Another interesting Anti-Null move position (from a real game)

Author: Vincent Diepeveen

Date: 10:17:57 06/15/04

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On June 14, 2004 at 19:20:57, Anthony Cozzie wrote:

It has nothing to do with double nullmove not finding it. Instead double
nullmove *does* find this.

Only normal nullmove doesn't find it.

It's of course like so many 'zugzwangs' another evaluation issue.

Just be sure you evaluate qd2+ kxg4 qe3 b5 axb5 as more positive than some
positions which start with gxh5.

That's all.

Diep finds it at 11 ply :

00:00     22 22 0 (2) 1 (0,0) -0.471 g4xh5 Kg5xh5
00:00    266 266 0 (2) 2 (0,1) -0.471 g4xh5 Kg5xh5
00:00    835 835 0 (2) 3 (0,3) -0.061 g4xh5 Qh4-g4 Kg2-f1 g6xh5 Qd4xb6 Qg4xe4 Qb
6xa5 Kg5-h6
00:00 147450 2949 0 (2) 4 (0,6) -0.061 g4xh5 Qh4-g4 Kg2-f1 g6xh5 Qd4xb6 Qg4xe4 Q
b6xa5 Kg5-h6
00:00 147680 7384 0 (2) 5 (0,15) -0.061 g4xh5 Qh4-g4 Kg2-f1 g6xh5 Qd4xb6 Qg4xe4
Qb6xa5 Kg5-h6
00:00 180507 25271 0 (2) 6 (2,35) -0.133 g4xh5 Qh4-g4 Kg2-f1 Qg4-f4 Kf1-g1 g6xh5
 Qd4xb6 Qf4-e5
00:00 192151 74939 0 (2) 7 (10,92) -0.139 g4xh5 Qh4-g4 Kg2-f1 Qg4-f4 Kf1-g1 Qf4-
g3 Kg1-h1 g6xh5 Qd4xb6 Qg3-e5
00:01 229359 311929 0 (2) 8 (25,245) -0.080 g4xh5 Qh4-g4 Kg2-f2 Qg4-f4 Kf2-g1 Qf
4-g3 Kg1-h1
00:02 248265 585907 0 (2) 9 (56,492) -0.547 g4xh5 Qh4-g4 Kg2-f2 Qg4-f4 Kf2-g1 g6
xh5 Qd4xb6 Qf4xe4 Qb6xa5 Kg5-g4 Qa5-c5 Qe4-b1 Kg1-h2 Qb1xb3
00:06 271934 1707751 0 (2) 10 (145,1157) -0.561 g4xh5 Qh4-g4 Kg2-f2 Qg4-f4 Kf2-g
1 g6xh5 Qd4xb6 Qf4xe4 Qb6xa5 Kg5-g4 Qa5-c5 Qe4-e1 Kg1-g2 Qe1-g3 Kg2-h1 Qg3-h3 Kh
1-g1 Qh3xb3
00:18 283545 5205900 0 (2) 11 (368,2660) -0.836 g4xh5 Qh4-g4 Kg2-h2 Qg4xh5 Kh2-g
3 Qh5-g4 Kg3-f2 Qg4-e6 Qd4-e3 Kg5-f6 Qe3-d4 Kf6-f7 Qd4-e3 Kf7-g7
++ d4-d2 procnr=0 terug=-561 org=[-836;-835] newwindow=[-836;520000]
00:34 293568 10013609 0 (2) 11 (565,3928) 11.263 Qd4-d2 Kg5xg4 Qd2-e3 b6-b5 a4xb
5 a5-a4 b5-b6 a4xb3 b6-b7 b3-b2 b7-b8Q Qh4-h1 Kg2xh1 b2-b1Q Kh1-g2
00:39 297525 11814753 0 (2) 12 (592,4329) 11.263 Qd4-d2 Kg5xg4 Qd2-e3 b6-b5 a4xb
5 a5-a4 b5-b6 a4xb3 b6-b7 b3-b2 b7-b8Q Qh4-h1 Kg2xh1 b2-b1Q Kh1-g2
01:39 304837 30212461 0 (2) 13 (1154,8778) 11.263 Qd4-d2 Kg5xg4 Qd2-e3 b6-b5 a4x
b5 a5-a4 b5-b6 a4xb3 b6-b7 b3-b2 b7-b8Q Qh4-h1 Kg2xh1 b2-b1Q Kh1-g2
02:37 312094 49042542 0 (2) 14 (1324,10654) 11.263 Qd4-d2 Kg5xg4 Qd2-e3 b6-b5 a4
xb5 a5-a4 b5-b6 a4xb3 b6-b7 b3-b2 b7-b8Q Qh4-h1 Kg2xh1 b2-b1Q Kh1-h2 Qb1-c2 Qe3-
f2

>On June 14, 2004 at 16:31:17, Jaime Benito de Valle Ruiz wrote:
>
>>[d]8/8/1p4p1/p5kp/Pp1QP1Pq/1P6/6K1/8 w - - 0 62
>>
>>White moves and wins!
>>Can your engine find the right answer and give the proper "crushing" score
>>(around 9 pawns!) along with a proper PV? How long does it take?
>>Mine doesn't find anything after a long long time (over an hour), but with
>>null-move disabled, it takes only a few seconds to show the full PV.
>>(Some engines find the right answer, but with a small score, an absurd PV, and
>>they change their mind some plies later)
>>
>>In this position the black king is in a very delicate position: After a couple
>>of moves, if the black queen moves, white checkmates inmediately, so both kings
>>and queens must remain still while pawns play on their own.
>>
>>Any good suggestion to avoid this problem with null-move?
>>
>>Regards,
>>
>>  Jaime
>
>Zappa doesn't get it either (gxh5 @ 15 ply after 1 minute).  Zappa relies on
>double nullmove for zugzwang avoidance.  This works find for positions with 1
>zugzwang, but in this position black gets hit with about 10 of them :)
>
>anthony



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