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Subject: Re: Very easy mate to solve.

Author: leonid

Date: 17:43:11 12/25/01

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On December 25, 2001 at 12:51:34, Heiner Marxen wrote:

>On December 24, 2001 at 19:46:41, leonid wrote:
>>On December 24, 2001 at 16:27:29, Heiner Marxen wrote:
>[big snip]
>>>Otherwise I did not note anything unusual in Chest's statistics.
>>>Name the missing info and I will try to provide it :-)
>Hello again!


>>I actually looked into all useful data of your program before even putting this
>>positions here.
>Oh, sorry.  I'll remember that, now :-)

Never mind! I actually looked only into branching factor and difference of speed
in initial plys. This is the most interesting and this is where I expect to try
to obtain some additional speed when finally I will come to this. For now I see
only two possibility in speeding:

1) initial plys.

2) usage of already found variables when switching for next depth.

For now each time when program make search for indicated depth (even when before
it looked already into depth n-1) mine initialise all variables.

In general, I think that our both programs could be still speeded in around 5 or
10 times. Ten times for 10 moves search. Problem right now for you and me is
that we are, probably, not that much motivated to enter once again into deep
code rewriting. Not that much demand for mates solvers, also we both stay too
far away from almost every solver ever done.

>> Was very surprise in finding that time of search for 5 moves was
>>less that time for 4 moves. Your time for 4 moves was 0.11 sec and for 5 only
>>0.05 sec.
>Were that timing info lines from one invocation/run, or resulting times
>from different invocations?  The former would be strange, the latter is ok,
>since with so small times it may just be random inaccuracy noise.
>Or is that repeatable?

For this position I asked your program to see only once. In other positions I
saw something like this, probably, one or two times. It is rare. Still it could
be correct. In around 15% of positions, when mate really exist, mate in N moves
deep take less time that mate N-1 moves.

>> Also big difference in our time is due to some sudden jump in
>>branching factor that happened in mine after move 6. Move 6 was still 1.5 sec.
>>for my program
>For this I have no idea.
>>The most curious in this position was also the fact that it was not so much
>>lowers specialised plies that gave you advantage but your branching factor in
>>upper plies. Your time for 4 move was 0.11 sec, when mine was 0.05 sec.
>So it is all about EBF, since your basic speed here is even better than mine.

Sorry, I did a mistake in my wording. I wanted in reality say that your program
had much better branching factor in moves after 4. So in move 5, 6, 7 and so



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