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Subject: Re: correct SAN notation ?

Author: Gerd Isenberg

Date: 04:29:06 12/20/02

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On December 19, 2002 at 19:36:18, Andreas Herrmann wrote:

>On December 19, 2002 at 18:48:45, Gerd Isenberg wrote:
>
>>On December 19, 2002 at 16:12:24, Andreas Herrmann wrote:
>>
>>>>Hi Andreas,
>>>>
>>>>i think Rcf2 is not incorrect here, don't considering invalid moves due to
>>>>pinned pieces. Better to have redundant rather than missing information. Your
>>>>SAN-parser should handle both Rcf2 and Rf2 correctly (but not Rff2 ;-)
>>>>I guess writing the move is more or less implementation depending, even if an
>>>>exact definition about this issue exists.
>>>>
>>>>Regards,
>>>>Gerd
>>>
>>>Hi Gerd,
>>>
>>>yes you are right. Holmes also accepts moves without the check "+" or "checkmate
>>>"#" characters or with the remark characters "!" or "?".
>>>
>>>But in the above case i have problems, because in the root i generate only legal
>>>moves (no pseudolegal ones). And from all possible legal moves i generates a
>>>SAN, a LAN and coordinate notation list to compare them with the input move. If
>>>the input is not a legal move (SAN, LAN or coordinate input) than i try to
>>>delete or add the above characters (+,#,!,?) and compare again, that's no
>>>problem.
>>>
>>>To produce a notation like Rcf2 i have to generate also pseudolegal moves in the
>>>root, because only in this case i have 2 possible rook moves to the same target
>>>square. I think this extra work stands in no relation to this rare case.
>>
>>Yes i see. But string compare?
>>If you parse a move string from left to right, character for character, i would
>>suggest a kind of finite state machine, where a current (initial) state and the
>>next character define some action (eg. tagging or shrinking the move list) and
>>an next state.
>
>Yes Dieter Bürßner explaned me something similar in the Winboard forum, but i
>think normaly a GUI has to send and export the correct SAN notation.
>Perhaps i will change my code after the IPCCC. But at the moment i have to find
>500 or more ELO in Holmes to beat Isichess in Paderborn ;-)
>

A bit overstated ;-)

>>
>>Nice to have bitboards ;-)
>
>At the moment i'm just searching for a faster solution for calculation the SEE
>value. But i think this would be easier and faster with bitboards.
>Can you give me some hints?

Don't use explicite SEE. I have some bitboards with defending properties, like
defended by pawn, by light pieces, defended more than once, or not defended at
all, etc. This is also usefull for none captures. I combine these with MVV/LVA
ordering and only prune obviously loosing none checking captures like Queen
takes Pawn defended by Pawn in qseach.

Gerd

>
>Currenty i have changed my move ordering from SEE back to MVV/LVA because my SEE
>code was much too slow.
>
>>
>>>
>>>have a nice day
>>>Andreas
>>
>>and a nice night,
>>Gerd
>>
>>
>>>
>>>PS: Have you heard something from Jochen, because he stands not in the IPCCC
>>>participants list? So i'm fighting only with Matador for the "Rote Laterne" next
>>>year :-)
>>
>>No, heard nothing about Jochen.
>>But the number is still odd, so hopefully...
>>A damned strong field.
>
>Yes perhaps stronger than the last WM.
>
>Andreas



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