Stalemate Tablebases

Discussion of chess software programming and technical issues.

Moderators: hgm, Dann Corbit, Harvey Williamson

Forum rules
This textbox is used to restore diagrams posted with the [d] tag before the upgrade.
Dries
Posts: 9
Joined: Sun Jan 17, 2021 10:26 am
Full name: Dries De Clercq

Re: Stalemate Tablebases

Post by Dries » Mon Feb 22, 2021 2:51 pm

Alright. I looked up chess with different armies. Must be very interesting. Kind of sad perhaps that it's seen so rarely.

User avatar
Ajedrecista
Posts: 1537
Joined: Wed Jul 13, 2011 7:04 pm
Location: Madrid, Spain.
Contact:

Re: Stalemate tablebases.

Post by Ajedrecista » Tue Feb 23, 2021 7:03 pm

Hello Dries:

Your thread is quite interesting! There have been very nice stalemates in actual games and in studies and I enjoy them quite a lot.

My two cents: I have just made up a 7-man example of forced stalemate in one:

[d]6K1/3R2P1/6rk/7p/7P/8/8/8 b - - 0 1

Of course 1.- ..., Rxg7+ {other moves lose}; 2.- Rxg7 {other moves lose} ½-½ {draw by stalemate}.

Regards from Spain.

Ajedrecista.

User avatar
Ajedrecista
Posts: 1537
Joined: Wed Jul 13, 2011 7:04 pm
Location: Madrid, Spain.
Contact:

Re: Stalemate tablebases.

Post by Ajedrecista » Wed Feb 24, 2021 7:27 pm

Hello again:

I have made up other example just for fun. This time is a stalemate in two. It starts with nine pieces, which is too much for current EGTB, but finishes with seven pieces. It is inspired in Damiano's checkmate pattern but arranging the pieces for a stalemate:

[d]7k/8/5N2/R5R1/r5r1/5p2/5P2/5K2 b - - 0 1

1.- ..., Ra1+ {other moves lose}; 2.- Rxa1 {only move}, Rg1+ {other moves lose}; 3.- Kxg1 {or Rxg1} ½-½ {draw by stalemate}.

There is not a single last move but at least all the last moves lead to stalemate.

It is quite fun to compose these problems but I understand that this is not the point of your thread.

Regards from Spain.

Ajedrecista.

Dries
Posts: 9
Joined: Sun Jan 17, 2021 10:26 am
Full name: Dries De Clercq

Re: Stalemate Tablebases

Post by Dries » Wed Feb 24, 2021 8:06 pm

Thanks! I've checked them out. Those are nice examples. The last one is quite an interesting position.

Well, I was kind of wondering how deep a stalemate someone might find under these strict conditions, namely, that the stalemate can be forced and that going for a forced stalemate is the only way to prevent a loss. But that's quite a tough task to undertake.

User avatar
hgm
Posts: 25864
Joined: Fri Mar 10, 2006 9:06 am
Location: Amsterdam
Full name: H G Muller
Contact:

Re: Stalemate Tablebases

Post by hgm » Wed Feb 24, 2021 8:21 pm

I suppose you could base a very deep stalemate on a position with a 'rabid Rook'. Where the Rook drives the King with checks through a corridor of pieces, until it reaches a dead end:


Dries
Posts: 9
Joined: Sun Jan 17, 2021 10:26 am
Full name: Dries De Clercq

Re: Stalemate Tablebases

Post by Dries » Wed Feb 24, 2021 8:41 pm

Yeah. I just asked, down at chess.com, if someone could find a stalemate that goes deeper than a stalemate in 2, which is deepest position that I had. I don't see any better idea than to do the thing you describe.

I'm also guessing that stalemate tablebases wouldn't go very deep. Perhaps it would be up to some manual attempt to find the deepest stalemate... if that wouldn't have been done already by someone.

Dries
Posts: 9
Joined: Sun Jan 17, 2021 10:26 am
Full name: Dries De Clercq

Re: Stalemate Tablebases

Post by Dries » Thu Feb 25, 2021 3:52 pm

Someone shared a stalemate in 4. Or self-stalemate in 4, since you want to stalemate yourself.



Perhaps those stalemate tablebases weren't such a good idea anyhow. I guess they might be too rare. Perhaps it's a good thing no one actually tried to make them...

Post Reply