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Subject: Re: The Null Move Killer

Author: Will Singleton

Date: 21:52:04 09/29/04

On September 29, 2004 at 23:52:15, Stuart Cracraft wrote:

>[D] 4r1k1/p1qr1p2/2pb1Bp1/1p5p/3P1n1R/1B3P2/PP3PK1/2Q4R w - - bm Qxf4;
>
>In this position I had everything turned on and got the solution
>in a little more than 1 1/2 minutes:
>
> 1/11  g2f1  0.01 -953      945 g2f1 f4d5
>                                g2f1 f4d5
> 2/12  g2f1  0.01 -953     1644
>                                g2f1 f4d5 c1g5
> 3/12  g2f1  0.02 -953     5064
>                                g2f1 f4d5 c1g5 d5f6
> 4/20  g2f1  0.09 -953    20655
>                                g2f1 f4d5 b3d5 c6d5 c1c7 d6c7 f1g1
> 5/22  g2f1  0.65 -953   168943
>                                g2f1 b5b4 b3a4 f4d5 f6g5 d5e7
> 6/26  g2f1  2.59 -953   620310
>                                g2f1 b5b4 mtmt
> 7/32> g2f1 60.58 -552 14192153 g2f1 e8c8 c1b1 f4d5 b1e4 d6b4 f6e5 c7b6
>                                g2f1 e8c8 c1b1 f4d5 b1e4 d6b4
> 7/34  c1f4 99.42 5113 24537823 c1f4 e8e6 f4g5 d7e7 b3e6 e7e6 h1d1 d6e7 f6e7
>                                c1f4 e8e6 f4g5 d7e7 b3e6 e7e6 h1d1
>
>
>I turned off null move (R=2) and got the solution in about 11 seconds:
>
>Alpha=-1332 Beta=-531 Maxdepth=9999999 MaxTime=99999999
> 1/11 g2f1  0.01 -953      908 g2f1 f4d5
>                                g2f1 f4d5
> 2/12 g2f1  0.01 -953     1565
>                                g2f1 f4d5 c1g5
> 3/14 g2f1  0.07 -953    20084
>                                g2f1 f4d5 c1g5 d5f6
> 4/22 g2f1  0.60 -953   131543
>                                g2f1 f4d5 b3d5 c6d5 c1c7 d6c7 f1g1
> 5/26>g2f1  6.80 -552  1607444
>                                g2f1 b5b4 b3a4 f4d5 f6g5 d5e7
> 5/36 c1f4 10.70 2260  2466497 c1f4 d6f4 h4h5 g6h5 h1h5 f4h6 h5h6 c7g3 g2g3 d7d6
>
>                                c1f4 d6f4 h4h5 g6h5 h1h5 f4h6 h5h6 c7g3 g2g3 d7d
>
>So now my question is, would it make sense to consider an idea of
>disabling null move under additional circumstances if those
>circumstances can be identified.
>
>   endgame
>   side to move in check
>   inside principal variation
>   last move a null move
>
>These are the ones I disable for -- I don't disable null move for
>any material-related or alpha/beta related measures but perhaps
>I should. Are any in common use?
>
>Stuart

If the previous move was a piece moving near the enemy king, I don't null move.
Also, don't null near the leafs.

Re: The Null Move Killer Robert Hyatt 06:38:04 09/30/04
- Re: The Null Move Killer Stuart Cracraft 12:50:43 09/30/04
  - Re: The Null Move Killer Robert Hyatt 15:07:46 09/30/04
    - Re: The Null Move Killer Stuart Cracraft 15:23:20 09/30/04
      - Re: The Null Move Killer Robert Hyatt 17:02:34 09/30/04
        
        Re: The Null Move Killer Stuart Cracraft 09:28:00 10/01/04
        
        Re: The Null Move Killer Robert Hyatt 11:43:10 10/01/04
        
        Re: The Null Move Killer Stuart Cracraft 12:29:05 10/01/04
no null moves near the leafs? martin fierz 01:49:15 09/30/04
- Re: no null moves near the leafs? Stuart Cracraft 12:51:33 09/30/04
  - Re: no null moves near the leafs? martin fierz 15:49:50 09/30/04
    - Re: no null moves near the leafs? Stuart Cracraft 16:47:47 09/30/04

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