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Subject: Re: How you judge in your program: "opening", "middle game", "end game"

Author: blass uri

Date: 10:19:20 01/28/00

Go up one level in this thread


On January 28, 2000 at 12:31:29, Shep wrote:

>On January 28, 2000 at 11:31:29, Amir Ban wrote:
>
>>On January 28, 2000 at 05:25:26, Shep wrote:
>>
>>>On January 27, 2000 at 10:40:05, Jari Huikari wrote:
>>>
>>>>Where you consider the position of a game changes to middle game / end game?
>>>>
>>>>opening == most pieces haven't moved yet ? / opening book not ended yet ?
>>>>end game == few pieces left ?
>>>>middle game == neither of the two above ?
>>>
>>>I suppose some programs have a more fine-grained approach to this.
>>>Tiger for example divides the game into several "phases" (more than 3 for sure
>>>:) according to the material on the board, and different evals
>>>(/extensions/pruning/...?) are fired off according to the phase the program is
>>>in.
>>>In the DOS version, it would show "Phase x/y"; in Rebel Tiger, the best way to
>>>see it is when the eval suddenly jumps from like "+1.10" to "+0.20" (or vice
>>>versa) after a capture has occurred. (Contrary to Fritz, this is _not_ due to
>>>any preprocessor oddities. :)
>>>
>>
>>Why isn't it like Fritz ? It sounds exactly the same.
>
>It does not happen to Tiger that he says "+0.00" and then after the next
>capture, shows "-3.00" immediately. That would be a result that has been
>reported repeatedly about Fritz. Tiger's eval may go up or down a bit, but it
>does not miss losing moves just because it was "in the wrong phase".
>So I suppose there's a difference between the preprocessing Fritz employs and
>the things Tiger does between phases.
>
>Of course I cannot point the finger to it, not knowing either program's source
>code, but I figure that Tiger's approach is different (besides, such drastic
>eval changes (1 pawn or more) are _extremely_ rare for Tiger).


I do not understand.

Do you mean to say that the only difference between tiger and fritz is in the
size of the change in the evaluation?

Can tiger show scores of +0.4,+0.5,+0.5 +0.46 and never showing +0.9 and after
the expected moves scores of +0.9,+0.95,+0.93,+0.96?

If it can than I see no difference between tiger and fritz (except the size of
the change)

It is possible that you meant that tiger can show something like

depth 7 +0.4
depth 8 +0.5
depth 9 +0.5
depth 10-13 +0.9

and after the expected move
it can show from depth 1 to depth 10 evaluations of +0.9?

If this is the case than tiger is not a root processor but can have jumps in the
evaluation because of being a processor of something that is not the root but
close to the root.

Uri



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