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Subject: Re: Very easy mate to solve.

Author: leonid

Date: 17:25:34 12/28/01

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On December 28, 2001 at 19:41:52, Heiner Marxen wrote:

>On December 27, 2001 at 21:51:56, leonid wrote:
>
>>
>>Hi, Heiner!
>>
>>>>Just look into fact that with new depth procedure of search will be changed.
>>>>Specialized files, for instance, will be at new depth. Somewhere it can bring
>>>>different search sequence and with it even better time for higher depth.
>>>
>>>Aah!  Yes, you have a point, here.
>>
>>I tried today last position once again but starting this time search from 3
>>moves like, (3 4 5...). When before it was, (4 5 6...). Now I could see that
>>previous time for your program was wrong and your specilized plys work much,
>>much better that I could see previously. Fantastic!!!!! When before I found 0.11
>>sec for 4 moves, now I could see 0.0 sec.
>>
>>This finding could signify that my guessing about ten fold possible speeding of
>>mate solver is very sober expectation. It reality, it could be much higher.
>>
>>In the next position that I wrote yesterday, old tendency is more that present.
>>Our speed for 4 moves (all condition are the same) is around 9 times in your
>>favor. Mine at 4 moves is 0.44 sec. and your 0.05 sec. Even if mine have here
>>chance to have somehow better branching factor it reach your time only at 9
>>moves. Initial speed is really vital.
>>
>>[D]3k4/3qqqrp/N1qq3R/NQ1Q3q/n2qNRPQ/n7/B6b/BqQrQbQK w - -
>>
>>My time in general:
>>
>>Move            Time            Branching factor            NPS.
>>
>>4               0.439 sec                                   38k
>>                                4.87
>>5               2.14 sec                                    36k
>>                                4.64
>>6               9.94 sec                                    36k
>>                                5.3
>>7               52.8 sec                                    49k
>>                                4.69
>>8               4 min 8 sec                                 57k
>>                                8.52
>>9               35 min 13 sec                               64k
>>
>>Mate found in 10 moves at 1 hour 53 min.
>
>Interesting.  My timing is:
>#  4      0.09s [  4.50]        5kN [  5.24]  1.03        463-         0
>#  5      0.42s [  4.67]       26kN [  5.54]  1.29       1786-         0
>#  6      3.49s [  8.31]      189kN [  7.39]  1.51      16848-         0
>#  7     23.41s [  6.71]     1187kN [  6.27]  1.80     130157-         0
>#  8    146.17s [  6.24]     7333kN [  6.18]  2.13     871820-         0
>#  9    783.47s [  5.36]    39167kN [  5.34]  2.66    4764548-     22074
># 10   5019.44s [  6.41]   242350kN [  6.19]  2.86   30197115-  21449215
>
>Our NPS is nearly equal.  My inital speed is clearly better: when you have done
>depth 4, Chest has completed depth=5, already.  But although you do not use
>any hash, your EBF is better from 6 to 7 and to 8, while mine is better
>from depth 8 to 9.
>
>This may be due to luck, but it makes me curious: how do you manage such a
>good EBF?  How do you select black moves?  I know we both prefer checking
>moves, generally, but is there more to it in your program?
>Chest uses a really complicated function to order the black moves.
>You seem to be quite good in this respect, also.

It could be that our programs do very close search but each do it best on some
preferable one. It could that this one mine recognized as "preferable" one when
on previous it was clearly terrible looser.

Probably you do the same move ordering for black and white, at least in my
program logic is the same. Basically, program find all legal moves in advance
(exception exist but only in one specialized ply) and put checking moves at head
of its chain. No material evaluation ever done but something close to this
exist. Just after "first alignment" that was done in move generator (checking
moves are put there as first to go) come second aligment. Each move that take
some enemy piece, or make promotion, is aligned after expected gained value in
very rough way. For instance, taken of knight and bishop are not differentiated.
Taken of queen and every pawn promotion is regarded as equal. On the most
responsive plys two best moves are saved and used for "second aligment". One
move is "active" and second is "passive". Active move - move that is ckecking
move, or one that bring material advantage. Passive move - move other that
active.

Is this really close to what you have?

Even if I wanted few times to read what you have done, I still never make my
reading. Partially it is because I am lazy for every possible reading but even
more so because I don't remember any more C language.

Cheers,
Leonid.

>Cheers,
>Heiner



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