Solutions for 8/1p2k3/8/8/5Q2/8/ppp1p3/qrrbK3 w - - 0 1

[Ajedrecista]

Hello:

[...]

I am remembering right now a puzzle at TalkChess with white to play and win where the first move was Ke1 (I would say from d2) with a similar idea, with lots of black pieces on the kingside, all blocked. I think that a white a-pawn could run and promote, then pursue the black king through the board at knight jumps, to finally giving checkmate with something like ..., Kh3; Qh5#. However, I can not find it. I do not remember if it had such subtleties.

[...]

I finally found the position:

viewtopic.php?p=907433#p907433

The first move is Kxe1, not Ke1; the rest of the description was right. Once I replay through that PGN, I still think that it resembles a little with the problem of this thread in the sense of drive the king to their own pieces and giving checkmate there.

Regards from Spain.

Ajedrecista.

[peter]

Yes, the chase of the King with the single Queen reminded me to Hobacle's work(s) in that way too at first glance, even if I do know the position of the thread some longer than the one you quoted.
What I had underestimated way back then, when I first saw it here or in ACT (don't remember exactly, when it was, ACT5, where it's nr.21, I downloaed 2022, but the Chest- version it came along within the database it's in too, is from 2011 and it was mentioned here already way back then too

viewtopic.php?p=394041#p394041

, the most tricky point of it, I didn't realize till I reanalyzed it now, was the very special singularity of the first move being the only one to get White into the position of the right side to move and thus into the chance of denying Black's flight to h1 (or a8 before b- pawn has moved), regards

[Vinvin]

Hello:

[...]

I am remembering right now a puzzle at TalkChess with white to play and win where the first move was Ke1 (I would say from d2) with a similar idea, with lots of black pieces on the kingside, all blocked. I think that a white a-pawn could run and promote, then pursue the black king through the board at knight jumps, to finally giving checkmate with something like ..., Kh3; Qh5#. However, I can not find it. I do not remember if it had such subtleties.

[...]

I finally found the position:

viewtopic.php?p=907433#p907433

The first move is Kxe1, not Ke1; the rest of the description was right. Once I replay through that PGN, I still think that it resembles a little with the problem of this thread in the sense of drive the king to their own pieces and giving checkmate there.

Regards from Spain.

Ajedrecista.

In both positions, the winning line is a long sequence of zugzwangs.
An easy fix in code engines to play this kind of endgames better, would be : if a player has only king and/or pawn moves → disable Nullmoves.

[Ajedrecista]

Hello Peter:

[...]

What I had underestimated way back then, when I first saw it here or in ACT (don't remember exactly, when it was, ACT5, where it's nr.21, I downloaed 2022, but the Chest- version it came along within the database it's in too, is from 2011 and it was mentioned here already way back then too

viewtopic.php?p=394041#p394041

[...]

I have found other very similar positions, but I would say that they are derived from the one of the OP:

https://github.com/vondele/matetrack/bl ... 102018.epd

[...]
8/1p2k3/8/8/5Q2/8/ppp1p3/bqrbK3 w - - bm #50; 00:04+ @ C2/R0/K6/P2/X7;
[...]

------------

https://github.com/vondele/matetrack/bl ... dtrack.epd

[...]
8/1p2k3/8/8/8/8/pppQp3/qrrbK3 b - - bm #-49;
8/1p2k3/8/8/8/8/pppQp3/bqrbK3 b - - bm #-49;
[...]

For those wondering, ACT5 (Alternative Chess Test) and other versions of ACT can be downloaded from here.

Regards from Spain.

Ajedrecista.

[peter]

I have found other very similar positions, but I would say that they are derived from the one of the OP:

https://github.com/vondele/matetrack/bl ... 102018.epd

[...]
8/1p2k3/8/8/5Q2/8/ppp1p3/bqrbK3 w - - bm #50; 00:04+ @ C2/R0/K6/P2/X7;
[...]

------------

https://github.com/vondele/matetrack/bl ... dtrack.epd

[...]
8/1p2k3/8/8/8/8/pppQp3/qrrbK3 b - - bm #-49;
8/1p2k3/8/8/8/8/pppQp3/bqrbK3 b - - bm #-49;
[...]

Well, yes, first one is OP with exchanged places of two anyhow blocked figures of Black's, this one's in Chest.epd of download from 2011 too, and next two after already to d2 moved Queen, so just first ply of OP cut, again with the two versions of blocked figures arranged differently, these two aren't in my with Chest downloaded database.