Author: Heiner Marxen
Date: 11:24:14 12/30/02
Go up one level in this thread
On December 29, 2002 at 14:00:20, Les Fernandez wrote: >On December 29, 2002 at 08:24:22, Uri Blass wrote: > >>On December 29, 2002 at 08:11:13, John Lowe wrote: >> >>>On December 29, 2002 at 07:00:11, Uri Blass wrote: >>> >>>>On December 29, 2002 at 00:26:50, Les Fernandez wrote: >>>> >>>>>[D]4k3/8/8/8/8/2P5/1PPP4/4K3 w - - >>>>> >>>>>The above pawn structure to the best of my knowledge can't ever be reached since >>>>>the c3 pawn would have had to come from either b2-c2-d2. Are there alot of >>>>>these type of positions or are there a handful of pawn structures that we know >>>>>can't happen? >>>> >>>>I do not understand your question because I do not know what you mean by a lot. >>>> >>>>There are other pawn structures that cannot happen >>>>[D]8/8/8/8/8/P7/PPk5/K7 w - - 0 1 >>>> >>>>Doy you ask for the number or the relative number of illegal pawn structures? >>>> >>>>Uri >>>Hi Uri >>> >>>I wonder if the algorithm for spotting illegal pawn structures is complex or >>>only fairly simple.........? >> >>It may be possible to do a simple algorithm to spot part of the illegal pawn >>structures but i believe that an algorithm to spot all of them may be complex. >> >>Uri >>> >>>Illegal pawn structues don't happen in real games - human or computer so another >>>question is "could the identification of an illegal pawn structure _ever_ be >>>relevant in chess programming?" >>> >>>I don't think so..........you? >> >>I agree. >>I do not see how identification of an illegal pawn structure can be relevant for >>chess programs. > >Hello Uri, > >Well it may not be as relevant in chess progrmas but the work I am doing makes >it very relevant since I am generating chess positions with pawns for which I >need to know is a correct position or not. The ultimate answer to this is a "proof game", a legal game that yields the position in question. While some pawn structures are relatively easy to prove illegal (counting necessary captures and opponent pieces), this can become very complex. Construction of proof games is part of retro-analysis, and AFAIK, not at all easy in the general case. Cheers, Heiner >Les > >> >>Uri
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.