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Subject: Re: Explosion in WAC 102

Author: Miguel A. Ballicora

Date: 10:00:46 01/11/02

Go up one level in this thread


On January 11, 2002 at 12:47:29, David Rasmussen wrote:

>On January 11, 2002 at 12:40:03, Matthias Gemuh wrote:
>
>>On January 11, 2002 at 11:44:39, David Rasmussen wrote:
>>
>>>[D]2Q2n2/2R4p/1p1qpp1k/8/3P3P/3B2P1/5PK1/r7 w - - 0 1
>>>
>>>In the above position, my search tree explodes because of extensions. It takes >
>>>3 minutes and 42 million nodes to finish an 8 ply search. How does your program
>>>do?
>>>
>>>Any good ideas on how to limit extensions in such a position.
>>>
>>>P.S. Solving the position is no problem. It is a simple mate in 5 plies, and is
>>>found very early on at depth 1 or 2 or so. Still, there must be something
>>>unsound about my extensions, or at least room for improvement, when this
>>>position makes the tree explode.
>>>
>>>/David
>>
>>
>>
>>
>>My HyLogicChess has the following stats:
>>All extensions active.
>>Quiescence moves: 29% (no explosion, my average is normally have 40%)
>>Total moves searched: 11000
>>Speed; 84 kN/s
>>Move Ordering: 78% (normally 90%..92%)
>>[1] (0.18)  1.f3 (00h:00m:00s)
>>[2] (0.12)  1.Qb7 e5 (00h:00m:00s)
>>[3] (14.50)  1.Qxf8 Kh5 2.Rxh7 Kg4 3.Qxd6 (00h:00m:00s)
>>[4] (+Mate in 3)  1.Qxf8 Kh5 2.Rxh7 Kg4 3.f3 (00h:00m:00s)
>
>My program performs similarly if only searching to ply 4, but try letting it
>search to ply 9, even though it has already found the mate. That is what I am
>talking about.
>
>/David

Gaviota's output:

setboard 2Q2n2/2R4p/1p1qpp1k/8/3P3P/3B2P1/5PK1/r7 w - - 0 1
d
+-----------------+
| . . Q . . n . . |
| . . R . . . . x |
| . x . q x x . k |
| . . . . . . . . |
| . . . o . . . o |
| . . . B . . o . |
| . . . . . o K . |
| r . . . . . . . |
+-----------------+

sd 9
go
       104   1:      0.0   +30.78  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8xd6
       392   2:      0.0   +30.78  Qc8xf8   Kh6-h5   Rc7xh7   <EMPTY>
                                   <-transp
       455   3       0.0      :-)  Qc8xf8
       530   3       0.0      :-)  Qc8xf8
       565   3       0.0      :-)  Qc8xf8
      1637   3       0.0      :-)  Qc8xf8
      3104   3:      0.0   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8
      4023   4       0.1   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8
      4475   4:      0.1   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8
      5444   5       0.1   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8
      8853   5:      0.1   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8
     11891   6       0.1   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8
     18148   6:      0.2   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8
     24692   7       0.2   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8
     48189   7:      0.4   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8
     62166   8       0.6   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8
    152926   8:      1.5   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8
    172449   9       1.6   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8
    262305   9:      2.3   +Mat_3  Qc8xf8   Kh6-h5   Rc7xh7   Kh5-g4
                                   Qf8-g8

Ply: 9
Qc8xf8  Kh6-h5  Rc7xh7  Kh5-g4  Qf8-g8
Score: 125.37 (32094)  Evals: 90689   Time: 2.3s   nps: 115400  Q/all: 0.36
           nodes      cutoffs       missed     tree_exp
path      168830        26576          823         1.03
quies      93475        31592         1083         1.03
all       262305        58168         1906         1.03
hashtable=  attempts: 284553   hits: 35.3%   perfect: 23.2%
move c8f8





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