Verbesserung des Rekords von Gerald Ettl (P0006424) um einen Einzelzug.
James Malcom: Is this the length record for 32 units? (2021-02-16)
A.Buchanan: Isn’t there a length record catalogue by Alain Brobecker? (2021-02-17)
A.Buchanan: http://abrobecker.free.fr/chess/lengths.pdf (2021-02-18)
James Malcom: I do not find this in there. (2021-02-18)
A.Buchanan: Yes, I see now. I had thought that Alain's paper was comprehensive for its time, but I guess not. The "Number of last moves" space is a good candidate to be put in a PDB page, like the "first move" page. That's pretty easy to do, based on the structure that Alain has given, but some scholarship is required first to validate what the last records are 10 years on, for the different cases. For example there's Thierry Le Glueher's extensions of Gyula Breyer's stupendous matrix. Those are already in PDB. Should also reach out to the Usual Suspects to ask what they've done which should be included. I don't think that Alain is active in this particular area right now. Any volunteers to own it? :) I have too much going on right now to own this, but I am happy to support e.g. by searching WinChloe, proof-reading etc. There are some magnificent problems here: this is worth doing. (2021-02-19)
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Henrik Juel: sKf5 is in check from wTf3, so it is Black to move
With 11 white moves to reach mate, the stipulation should read #11, and the conventional numbering is 0... Sf4+ .. 11.Dxe5# (2020-04-19)
Henrik Juel: The missing men are wLLS and sPPP
8+5 promotions have happened, after the needed 3+2 pawn captures, e.g.
wPaxPb, wPcxPd, wPexPf, sPgxL, sPhxL
(The position would still be legal with one white light officer added to the diagram) (2020-04-19)
Henrik Juel: It may be that the 'conventional' numbering would ruin the PDB animation... (2020-04-19)
James Malcom: See the earlier 19 ply P1181666. (2021-02-06)
VL: My version of this problem, stipulated ###1, with wRf3 shifted to e3 was published in my article “Completely unavoidable mate” (The Problemist, v.24, No.6, November 2013; Pr.No.7), where ### denotes a CU-mate introduced in the article. (2021-02-09)
HBae: Autor nicht in Namenstabelle (2010-12-04, hidden) more ...
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correction of P1298046
Henrik Juel: 21 consecutive checks; unfortunately, the position is illegal.
White never captured, while black pawns captured six times by axbxcxd, b7xc6, c7xd6, and h7xg6; but [Pf2] could not have been captured.
Nowadays it is rare to see an illegal prize winner, so the diagram may be incorrect (Pg2?) (2015-02-25)
Henrik Juel: Now I see that Jacques, in his comment to P1298046, gave this position, so my last sentence does not apply (2015-02-25)
Henrik Juel: The illegality is even 'worse' than I first thought, because [Pe2] could not have been captured either (2015-02-27)
James Malcom: I think it would be nice to have a legal version of this record. To do this, I propose we shorten the solution until a legal position is reached.

A #9 with 33B2N1/qrrp1ppn/1Ppp1np1/2QN2k1/3PKR2/8/b2p2P1/8 seems legal, no? (2021-02-06)
Anton Baumann: störender Dual in der Lösung: ... 7.Sde7+ f5+ 8.Sxf5+ Te7+ 9.Dxe7+,Lxe7+,Sxe7+ ...
Die Stellung wird legal mit schwarzer Umwandlungsfigur: d2=sT! Aber es bleibt der Dual in der Lösung.
Mögliche legale Stellung, ohne Dual in der Lösung: a7=sT, b7=sD, -sBc6, wBb6 nach c6 (10+15) #10
Lösung: 1.Sfe7+ exd5+ ... 7.Sde7+ Ld5+ 8.Dxd5+ f5+ 9.Sxf5+ De7+ 10.Sxe7# (2021-02-11)
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A.Buchanan: The final move "Txg5#" was now correctly marked as an error, because it was ambiguous. Thanks Gerd! (2020-11-14)
Henrik Juel: Popeye 4.61 with 'opt thr 0' found no flaws (2020-10-24, hidden)
Anton Baumann: C+ Gustav 4.1d (2020-11-13, hidden) more ...
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SCHRECKE: C+, Gustav 4.1d, Brute Force (2020-10-25, hidden) more ...
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SCHRECKE: C+, Gustav 4.1d, Brute Force (2020-10-25, hidden)
Henrik Juel: The stipulation should be s#8, I think (2020-10-25, hidden)
James Malcom: Fixed. (2020-10-26, hidden) more ...
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Quelle: L'Unita, s. http://cerca.unita.it/ARCHIVE/xml/240000/235026.xml (14.05.2022: toter Link)
Alternativ: https://archivio.unita.news/assets/main/2007/08/14/page_019.pdf (14.05.2022 geprüft)

In 'L'Unita' ohne konkrete Forderung als Ergebnis einer Rekordkonstruktion mit dem Ziel "Doppelpatt in möglichst wenigen Zügen" veröffentlicht.
Henrik Juel: This non-unique proof game is probably the shortest to reach the diagram position (2020-11-17)
Mario Richter: For a detailed history of the hunt for the shortest PG see Enzo's interesting article "Nuovo record nello stallo reciproco" in 'Best Problems" Nr. 44 (issue 04/2007).
Btw., most sources call this a "double-stalemate" (not "mutual") ... (2020-11-18)
Mario Richter: s. http://www.bestproblems.it/bppdf/BP044.pdf (2020-11-18)
A.Buchanan: That is probably very difficult to find and unlikely that many unique proof games can exist of that form (2020-11-19)
James Malcom: I'm unaware of any unique PGS that end in a mutual stalemate, but surely it must be possible, who the genius may be. (2020-11-19)
A.Buchanan: We’re missing some keywords for stalemate and mutual stalemate objectives. Also what are construction task and record and what’s the difference? (2020-11-19)
Henrik Juel: Euclide 1.01 found no solutions in 17.5 moves (30 hours), so it is extremely likely that all shortest proof games last 18.0 moves (2020-12-01)
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Henrik Juel: the Keywords are wrong, James
and the stipulation is missing (2022-04-14)
James Malcom: Fixed. (2022-04-14)
Henrik Juel: thanks (2022-04-14)
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Henrik Juel: Very impressive, James
Black needs to post a promoted rook on g1 again and again to prevent the threat 2.Sg5+ T7xg5#
A promoted queen does not work, because of 2... Dxg5#
You should label it C+, despite the possible duals in short variations, I think (2023-06-03)
James Malcom: Thanks.
Labeled as intended, now.
This task took over two years to realize: http://superproblem.ru/archive/Labor/Malcom-S.html (2023-06-03)
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