ChessUSA.com TalkChess.com
Hosted by Your Move Chess & Games
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Prove that a position is legal and reachable.
Post new topic    TalkChess.com Forum Index -> Computer Chess Club: General Topics Flat
View previous topic :: View next topic  
Author Message
Uri Blass



Joined: 08 Mar 2006
Posts: 5958
Location: Tel-Aviv Israel
PostPost subject: Re: Prove that a position is legal and reachable.    Posted: Wed May 16, 2012 1:28 pm Reply to topic Reply with quote
DustinYoder wrote:
I am actually needing to find an algorithm that can prove that a given board position is reachable by some sequence of legal moves beginning from the standard chess initial position? Is this even remotely possible? I would prefer to have an algorithm that could execute in minutes rather than hours or days.
I realize this is super difficult and I'm almost positive it has not yet been done. I am just looking for direction, ideas and someone that might want to help try to solve this problem.[/b]


I believe that somebody did something like it and
I think that the way to do it is to have some evaluation function of distance from the opening position(based on the number of missing pieces and have some move generator that undo move instead of making moves).

Now you can simply start to unmake moves that reduce the distance to the opening position until you get into the opening position.

Note that I do not see a general solution and one of the problems may be with unreachable positions that the generator is not going to be able to prove that they are unreachable.

some rules to define if a position is unreachable may help and
knowing that patterns like Ba1 and pawn at b2 is unreachable can help.
Back to top
View user's profile Send private message
Display posts from previous:   
Subject Author Date/Time
Prove that a position is legal and reachable. Dustin Yoder Wed May 16, 2012 11:23 am
      Re: Prove that a position is legal and reachable. Julien MARCEL Wed May 16, 2012 11:45 am
            Re: Prove that a position is legal and reachable. Arpad Rusz Wed May 16, 2012 1:22 pm
      Re: Prove that a position is legal and reachable. Uri Blass Wed May 16, 2012 1:28 pm
      Re: Prove that a position is legal and reachable. Ricardo Barreira Wed May 16, 2012 1:49 pm
            Re: Prove that a position is legal and reachable. Julien MARCEL Wed May 16, 2012 1:55 pm
                  Re: Prove that a position is legal and reachable. Sven Schüle Wed May 16, 2012 2:43 pm
                  Re: Prove that a position is legal and reachable. H.G.Muller Wed May 16, 2012 6:25 pm
                        Re: Prove that a position is legal and reachable. George Tsavdaris Sat May 19, 2012 2:22 pm
      Re: Prove that a position is legal and reachable. Edmund Moshammer Wed May 16, 2012 2:49 pm
            Re: Prove that a position is legal and reachable. George Tsavdaris Sat May 19, 2012 1:50 pm
      Re: Prove that a position is legal and reachable. Joona Kiiski Wed May 16, 2012 6:39 pm
            Re: Prove that a position is legal and reachable. H.G.Muller Wed May 16, 2012 6:50 pm
                  Re: Prove that a position is legal and reachable. Alex Brown Wed May 16, 2012 10:57 pm
                        Re: Prove that a position is legal and reachable. Sven Schüle Thu May 17, 2012 9:01 pm
                              Re: Prove that a position is legal and reachable. Sven Schüle Thu May 17, 2012 9:27 pm
                                    Re: Prove that a position is legal and reachable. Arpad Rusz Thu May 17, 2012 9:58 pm
                              Re: Prove that a position is legal and reachable. George Tsavdaris Sat May 19, 2012 2:40 pm
                                    Re: Prove that a position is legal and reachable. Sven Schüle Sat May 19, 2012 8:56 pm
                                    Re: Prove that a position is legal and reachable. Alex Brown Sat May 19, 2012 9:27 pm
                  Re: Prove that a position is legal and reachable. Uri Blass Thu May 17, 2012 2:55 am
                        Re: Prove that a position is legal and reachable. H.G.Muller Thu May 17, 2012 8:39 am
      Algorithm Ideas Dustin Yoder Wed May 16, 2012 6:48 pm
            Re: Algorithm Ideas fernando Sat May 19, 2012 5:12 pm
      Re: Prove that a position is legal and reachable. Robert Hyatt Thu May 17, 2012 9:59 pm
            Re: Prove that a position is legal and reachable. George Speight Fri May 18, 2012 2:34 am
Post new topic    TalkChess.com Forum Index -> Computer Chess Club: General Topics

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum




Powered by phpBB © 2001, 2005 phpBB Group
Enhanced with Moby Threads