Author: Christophe Theron
Date: 21:47:58 01/28/00
Go up one level in this thread
On January 28, 2000 at 13:19:20, blass uri wrote:
>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
You cannot use this to judge if a program is a root processor or not.
The score of a deep line can be stored in the hash table, and once it is found
in one search (maybe after a very long time), it can be found immediately in the
next search because of HT persistency.
Christophe
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