HHS ('Schwalbe' Heft 71, Oktober 1981, S. 349): "ein schwarzer Schuft - lässt seinen Zwillingsbruder von einem weissen Söldner killen, um dessen Platz einzunehmen: ein regelrechter Krimi."
Als Vergleichsaufgaben sind in der 'Schwalbe' angegeben: G. Schweig (P0002287), Mortimer (P1394750), W. Naef & H. Klüver (P0002832)
A.Buchanan: It's curious that if we shift sK to e8 (i.e. make the position fully homebase) then it is sound as BP in 6.0! The magic of homebase! :) I don't know if it was a typo - maybe someone can check the magazine archive? (2021-10-19)
A.Buchanan: WinChloe & YACPDB don't know this composition. (2021-10-20)
Mario Richter: No typo, the position with black Kd8 was intended, the cook was found by the 'Schwalbe'-solvers (Heft 71, Oktober 1981, p. 349) (2021-10-21)
WolfgangA. Bruder: geht aber auch schon in 5 Zügen!
1.d4 e5 2.dxe5 d5 3.exd6 e.p. Se7 4.dxe7 Kxe7 5.Dxd8+ KxDd8
WABruder (2021-10-18, hidden)
SCHRECKE: Die BP von WAB funktioniert nicht, hier steht am Ende noch wSg1! (2021-10-18, hidden)
WolfgangA. Bruder: sorry hatte ich doch glatt übersehen. (2021-10-19, hidden) more ...
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Mario Richter: In der Lösungsbesprechung wurde die Forderung präzisiert: Wieviele (und welche) Steine zogen in der KBP mindestens?
Die richtige Antwort ist: 6 (sSb8, wSb1, wDd1, wKe1, wSg1, wTh1).
Die kürzeste BP braucht 12 Züge von Schwarz (Sb8xLc1-f3xTg1, dann zurück nach b8), wK und wSS können nur gerade Anzahlen von Zügen machen, wegen Th1-g1 muß also wD oder wTa1 ein Tempo verlieren. In Rahmen des 12-Züge-Limits schafft das nur die wD. (2010-05-24)
Moldenhauer: Computerprüfung: C+ NUPG cooked Stelvio 1.11 1 Sekunde.
Keine Lösung: BP 11.0, BP 11.5. (2023-04-06)
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Silvio Baier: C+ (Natch 2.4) (2009-07-15, hidden)
Moldenhauer: Ergänzung Stelvio 1.2. Keine Lösung BP 23.0, BP 23.5. (2023-05-20, hidden) more ...
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Silvio Baier: C+ (Euclide 0.93) (2009-05-12, hidden)
Moldenhauer: Ergänzung Stelvio 1.2. Keine Lösung BP 25.5, BP 26.0. (2023-05-20, hidden) more ...
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Henrik Juel: Dual: ... 4.d4 La6 5.d5 Tc8 6.d6 Tc7 7.dxc7 Db8 8.c8L d6 9.Lf5 ... (2004-02-12)
Moldenhauer: Ergänzung Stelvio 1.2. Keine Lösung BP 19.0, BP 19.5. (2023-05-20, hidden) more ...
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Henrik Juel: Black makes 15 captures.
The first 13.0 moves are correct by Euclide 1.0, but it takes some 4 minutes, so a complete test would probably take more than a day (2014-12-09)
paul: Jacobi checked the last 16 moves (in about 20 min). (2018-05-10)
Mario Richter: I would like to label this problem as a "Massacre PG", but the current definition of that term only knows of two-sided MPGs. Perhaps we could make the same differentiation as for "Homebase"?!
Btw., wasn't "popeye" best for such massacres?
rawbats confirms complete correctness of the problem after approx. 25 minutes. (2018-05-11)
Henrik Juel: Yes, Mario, Popeye is fairly good at this type
C+ by Popeye 4.61 in 57 minutes (2018-05-11)
A.Buchanan: @Mario: yes I agree it would be good to make massacre more specific. There are 69 massacres currently, almost all 2-sided, but maybe also some series-movers (unique or non-unique) which are currently not counted? (2018-05-12)
Moldenhauer: Computerprüfung: C+ Stelvio 1.2 2 Sekunden.
Keine Lösung: BP 16.0, BP 16.5. (2023-05-20, hidden) more ...
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Moldenhauer: Ergänzung: Stelvio 1.2. Keine Lösungen BP 12.5, BP 13.0.
Es ist wirklich eine Rarität dass es 2 komplette Lösungen gibt. (2023-05-20)
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Wikipedianer: Quelle: Tijdschrift van den NSB 05/1929, S. 162, Aufgaben Nr. 5220 (a) und 5221 (b). Teil eines Artikels "Rochade in Retros" (2021-05-02)
Mario Richter: 'Thema-Boek' (Nanning & Koldijk, 1948, S.27) nennt als Quelle ebenfalls Tijdschrift NSB, Mei 1929, dito in 'Outrageous ...' und anderen Quellen.
Frage ist also, ob in beiden Magzinen publiziert oder ob bei der Quelle 'TfS' nur eine Verwechslung vorlag. (2011-11-25, hidden)
Henrik Juel: diagram error
Ph6 should stand on h7 (2021-05-02, hidden) more ...
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VL: AP after Keym. Solution:
I: 1.Sf6+.
II: Bl's try to be on move. 0... Bxb7+! 1.Ke3! O-O-O (legalizing!) 2.Sb6#. (2007-01-26)
A.Buchanan: Very nice problem. But why didn't VL say "Omigod! Sorry chaps: this problem doesn't work without PRA! You need to add it!" Answer: because PRA is irrelevant. So can't we get rid of it from most of the stipulations? (2022-02-15, hidden) more ...
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A.Buchanan: Tried some experiments to see if other formats of position entry are possible, but having reverted those, the solution animation no longer works. The usual PDB problem of hidden & undocumented variables between stipulation, diagrams & solution animation, sigh. (2021-04-01)
A.Buchanan: I found a "fix" - I added a bogus empty diagram b! How random! (2021-04-02)
A.Buchanan: For h#, I run Popeye without opti noca, so can see all the retro tries explicitly. For d#, I would apply opti noca if relevant, else lines of play might be blocked (2021-04-04)
Jan Hein Verduin: Composer is Johannes J. Burbach, and not Awerbach (2021-03-31, hidden)
hpr: Fixed (2021-03-31, hidden)
A.Buchanan: Have reported this to Gerd - I hope he can correct the infuriating internal state, which even the "recalculate solution" button is useless to repair... (2021-04-02, hidden)
Henrik Juel: C+ Popeye 4.61 also (with 'opt noc h1') (2021-04-03, hidden) more ...
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SCHRECKE: Nicht 1. Kb3 0-0-0?? 2. Ka2 Td3 3. Ka1 Txa3#, da Weiß zuletzt mit K oder T gezogen hat! (2023-06-28, hidden) more ...
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Mario Richter: Luboš Kekely (Slovakia) correctly points out that 1. ... Sf5! 2. 0-0-0 Sd6# is only a try and not a solution (last black move must have been by King or Rook, so the queenside castling is illegal).
I have changed the solution accordingly. (2023-03-10)
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Henrik Juel: Ljubomir had an anonymous co-author?? (2021-10-31)
A.Buchanan: I've no idea. There were three users called "anonymous" of different kinds, so I merged them into one, that's all. (2021-10-31)
A.Buchanan: I think anticipated in 1948 by Peter Kniest P0003606 (2021-11-01)
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Retro-Patt, Excelsior
TLi entdeckte ein eindeutiges Satzspiel: 1. ... ... 2. Th3 f4+ 3. Kf6 f5 4. Kg7 f6+ 5. Kh8 f7 6. Th7 f8=D# mit Echo in der gegenüberliegenden Ecke!
A.Buchanan: This tourney is not about "Whose move?" problems, but the distinct notion of "No legal last move for White" Particularly pernicious that someone add this question to the stipulation. We have no right to change the author's stipulation, which is part of their creative work (2020-09-30, hidden) more ...
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Henrik Juel: Black just moved K or T, so he cannot defend with 1... 0-0
White moved his king to allow Te2 to enter, so he cannot mate with 1.0-0 thr. 2.Tc1 thr. 3.Tc8# (2022-05-10)
Henrik Juel: C+ Popeye 4.61 and analysis (2022-05-10, hidden) more ...
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"These promoted piece games are anticipated in general idea by CMF" (TRD)
Moldenhauer: Computerprüfung: C+ KBP 5.5 cooked in 1 Sekunde.
Keine Lösung: vor BP 5.5.
Beispiellösung:1.g4 d5 2.g5 h6 3.gxh6 Dd6 4.hxg7 Ddxh2
5.gxh8=T Dxh1 6.Txh1 (2023-03-22)
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Konstruktionspreisausschreiben 'Die Schwalbe' 06/1973 Heft 21 S. 54,
Thema I (Dr. W. Dittmann):
Konstruiere, ausgehend von der Partieanfangsstellung, durch Versetzung von höchstens vier beliebigen Steinen eine partiemögliche Stellung mit Weiß am Zuge, deren kürzeste Beweispartie möglichst lang ist. Als Steinversetzung gilt die Postierung eines Steins auf einem anderen Feld oder auch die Entfernung eines Steins vom Brett. Gewertet wird nach der (möglichst hohen) Anzahl der Züge, die erforderlich sind, um die eingesandte Stellung von der Grundstellung aus zu erspielen.
Moldenhauer: Computerprüfung: C+ NUPG cooked Stelvio 1.11 1 Sekunde.
Keine Lösung: BP 28.5, BP 29.0.
Notation: 1.Sa3 Sa6 2.Sb5 Tb8 3.Sd4 Ta8 4.Se6 Tb8 5.Sxf8 Ta8 6.Se6 Tb8 7.Sc5 Kf8 8.Sa4 Ke8 9.Sb6 Kf8 10.Sxc8 Ke8 11.Sb6 Kf8 12.Sa4 Ke8 13.Sc3 Kf8 14.b4 Ke8 15.La3 Kf8 16.Db1 Ke8 17.Kd1 Kf8 18.Kc1 Ke8 19.Kb2 Kf8 20.Dd1 Ke8 21.Sb1 Kf8 22.Kc3 Ke8 23.Kd3 Kf8 24.Ke3 Ke8 25.Kf3 Kf8 26.Kg3 Ke8 27.Kh3 Tc8 28.Lc1 Ta8 29.b5 Sb8 30.b6 (2023-04-09)
A.Buchanan: In order to (H)C+ a non-unique proof game, one should show there is no short solution, but also that all solutions of regular length exhibit the intended theme, whatever that was. As long as any strategy can be checked for compliance, Stelvio fine because one can set the parameter for Stelvio to make sure that all strategies are considered. But it’s not possible currently to view all transpositions of a strategy, if that matters (2023-04-09)
Moldenhauer: Man müsste natürlich dieses Konstruktionsausschreiben gelesen haben was hier die Vorgabe war.
Die Stellung an sich oder der Königsmarsch oder dass die Damen und Läufer die Ursprungsposition
wieder einnehmen, usw. Stelvio wird das erreichen der Stellung analysieren so wie Euclide und Natch.
Die Bewertung auf C+ überlasse ich auch den Experten. Da fehlt mir Wissen und jahrelange Erfahrung.
Deshalb nur Kommentare. Gibt es dieses Ausschreiben von 06/1973? (2023-04-27)
Mario Richter: Thema ergänzt - hilft das bei der Bewertung? (2023-04-28)
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Konstruktionsausschreiben 06/1973
Moldenhauer: Computerprüfung: Cooked Stelvio 1.11 4 Sekunden.
Keine Lösung: BP 27.5, BP 28.0, BP 29.0. BP 28.5 cooked.
Beispiel BP 29.5: 1.Sa3 Sa6 2.Sb5 Tb8 3.Sd4 Ta8 4.Sc6 Tb8 5.Sxd8 Ta8 6.Sc6 Tb8 7.Sa5 Kd8 8.Sc4 Ke8
9.b4 Kd8 10.La3 Ke8 11.Db1 Kd8 12.Kd1 Ke8 13.Kc1 Kd8 14.Kb2 Ke8 15.Kc3 Kd8 16.Kd3 Ke8 17.Ke3 Kd8
18.Kf3 Ke8 19.Kg3 Kd8 20.Dd1 Ke8 21.Lc1 Kd8 22.Sa3 Ke8 23.Sb1 Kd8 24.b5 Ke8 25.b6 Kd8 26.h4 Ke8
27.Kh2 Ta8 28.h5 Sb8 29.h6
Beispiel BP 28.5: 1.Sa3 Sa6 2.Sb5 Tb8 3.Sd4 Ta8 4.Sc6 Tb8 5.Sxd8 Ta8 6.Sc6 Tb8 7.Sa5 Kd8 8.Sc4 Ke8
9.b4 Kd8 10.La3 Ke8 11.Db1 Kd8 12.Kd1 Ke8 13.Kc1 Kd8 14.Kb2 Ke8 15.Kc3 Kd8 16.Kd3 Ke8 17.Ke3 Kd8
18.Kf3 Ke8 19.Kg3 Kd8 20.Dd1 Ke8 21.Lc1 Kd8 22.Sa3 Ke8 23.Sb1 Kd8 24.b5 Ke8 25.b6 Kd8 26.h4 Ke8
27.h5 Ta8 28.Kh2 Sb8 29.h6
Nach Konstruktionsauschreiben glaube ich wäre BP 28.5 richtig. (2023-05-12)
James Malcom: Fixed. (2023-05-13)
Henrik Juel: What was asked for in this construction tourney? (2023-05-13)
Moldenhauer: Bitte siehe P0005590, da gings schon mal darum. (2023-05-13)
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VL: Published in "Probl. Pribuzh." (or "Problemy Pribusch'ja"?),
1990, No.1, #12. An obscure Russian language chess problem
magazine issued in Nikolaev, the Ukraine (the South Bug
riverside region). (2006-01-27)
A.Buchanan: Lovely problem, but this is no more PRA than it is duplex. Rather, the push/pull of AP Type Keym gives a forfeit which must be discharged. (2023-07-22)
Andrey Zhuravlev: The correct name of this magazine is "Problemist Pribuzhya" (2006-04-10, hidden) more ...
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s.a. Version P1214063
Joost de Heer: Compare with P1000230. (2022-08-05)
Henrik Juel: 6 hours with Euclide 1.01 produced nothing (2022-08-05)
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A.Buchanan: I imagine that e.g. 12. ... Tc8 would allow the removal of the "exactly" limitation, which is unsavory in a tempo problem. (2018-12-12)
A.Buchanan: Yes confirmed C+ BP 12.0 after 12. ... Tc8 with Euclide 1.11. (2018-12-12)
A.Buchanan: Ronald wrote: As far as i'm concerned a game in 11 moves doesn't solve a proof game in 11.5 moves. The normal stipulation (in those days, in English) was "Position after White's 12th move. What was the game?" Which is specific and is in English, as against "PG11.5".

I happen to disagree with Ronald's position on the vexed "exactly" question, particularly for a tempo problem. But I do defend his right to retain his original stipulation associated with the problem. It is part of his creative work and as a matter of respect, scholarship and insurance it should never be over-written. There is a dependency in PDB between the animation and the diagram stipulation, which encourages over-writing. We need a unicode Originalforderung field (or maybe keyword parameter) which can contain the original stipulation in its entirety. Obviously most stipulations are unaffected, but retros are more vulnerable. Having the Originalforderung field would also free up the diagram stipulation for *greater* automation (e.g. standardization on language, helpmate, try, set play, decimal-comma-or-decimal-point, which would allow much more focused search than is available now, and a similar kind of auto-translation to what occurs in keywords and fairy pieces today). (2020-12-30)
paul: The stipulation is actually PG in 11.5:
1. g4 e6 2. g5 Ke7 3. g6 Kf6 4. gxh7 Kg6 5. hxg8=S Th3
6. Se7+ Kh7 7. Sc6 dxc6 8. Lg2 Sd7 9. Ld5 Sf6 10. Lf3 Dd5
11. Lg2 Ld7 12. Lf1 (2011-11-24, hidden)
Henrik Juel: The shortest proof game is in 11.0, but this is cooked.
The stipulation should be something like PG in exactly 11.5 (2011-11-25, hidden)
Henrik Juel: C+ by Natch 3.1 (1 sec.) (2018-12-10, hidden)
A.Buchanan: Ronald wrote: As far as i'm concerned a game in 11 moves doesn't solve a proof game in 11.5 moves. The normal stipulation (in those days, in English) was "Position after White's 12th move. What was the game?" Which is specific and is in English, as against "PG11.5".
I happen to disagree with Ronald's position on the vexed "exactly" question, particularly for a tempo problem. But I do defend his right to retain his original stipulation associated with the problem. It is part of his creative work and as a matter of respect, scholarship and insurance it should never be over-written. There is a (still completely undocumented) dependency in PDB between the animation and the diagram stipulation, which has had the pernicious effect of encouraging casual over-writing of stipulations. We need a unicode Originalforderung field which can contain the original stipulation in its entirety. Obviously most stipulations are unaffected, but PDB's original heartland is retro, where many of these nuances are to be found, so one might expect a bit more sympathy. Having the Originalforderung field would also free up the diagram stipulation for *greater* automation (e.g. standardization on language, helpmate, try, set play, decimal-comma-or-decimal-point, which would allow much more focused search than is available now, and a similar kind of auto-translation to what occurs in keywords and fairy pieces today). Alas the damage is done: we just don't know what the Originalforderung was in many cases, or how close what we have now is to the original. (2020-12-30, hidden) more ...
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A.Buchanan: Solved in YouTube: https://www.youtube.com/watch?v=jtEu5g7rUVs (2022-02-17)
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Henrik Juel: Natch 3.1 did nothing in an hour
and neither did Euclide 1.01 (2018-12-13)
Moldenhauer: Computerprüfung: C+ Stelvio 1.0 02:33:48 Stunden.
Keine Lösung: BP 23.0, BP 23.5. (2023-02-18)
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Moldenhauer: Computerprüfung: Cooked Stelvio 1.31 8 Sekunden.
Keine Lösung: BP 19.0.
Beispiel: 1.a4 h5 2.a5 h4 3.a6 h3 4.axb7 hxg2 5.h4 g5 6.Th3 g4 7.Td3 g3
8.Sf3 g1=S 9.Txd7 Sh3 10.Lxh3 g2 11.d3 g1=S 12.Kf1 a5 13.Se1 Sf3 14.Le3 Sd2+
15.Dxd2 a4 16.Dc3 a3 17.Sd2 a2 18.Tc1 a1=S 19.f3 Sb3 20.Sxb3 (2023-06-19)
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Henrik Juel: C+ by Euclide 1.01 also, but in just 71 seconds (2016-06-16)
Reto: C+ also by Stelvio 2.0 in under 10sec (2024-01-07)
Per Olin: The 7th move by Black is 7. - Thh6. The automatic move sequence is disturbed as is chosen 7. - Tfh6. (2016-06-16, hidden) more ...
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VL: One solution consists of two partial ones, and there is another, castling independent, solution. A rare scenario; cf. P1091926. Presently, due to Art.16 (3) of the Codex, the mark "RV" may be deleted from the stipulation. (2017-11-25)
A.Buchanan: Methodologically, I think that one applies PRA first. So there are two parts, and each has two solutions. One solution is shared across both parts (2023-08-22)
A.Buchanan: I think "RV" used to mean *all* retro variants considered as separate histories, but since Werner Keym's revision, its meaning has been changed to be synonymous with PRA. The interpretation of this problem is now considerably less smooth than it was before. I would say that normally we must split into PRA parts before considering the number of solutions. So for me there are 2 parts, and each has 2 solutions, one of which is shared across the two parts, but that is a different way of fiddling around from VL's idea.
At what point was "2.1..." added to the stipulation? Of course, the problem works as PRA somehow, but I don't think this is a justification for changing the meaning of this term. And without an "originalforderung" field, we have no way to track edits to the stipulation.
I think this is a case for Golden Age: to preserve this old problem in its original form. (2023-08-21, hidden) more ...
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Moldenhauer: Computerprüfung: C+ Stelvio 1.11 13 Sekunden.
Keine Lösung: BP 22.5, BP 23.0. (2023-03-28)
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Anton Baumann: C+ Alybadix (2023-02-25)
Anton Baumann: BuB 'Die Schwalbe' 04/2003 S.103:
Es fehlt der Zusatz:"nach Andreas Thoma" (2023-06-05)
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No. 2142 HN
James Malcom: Due to the implementation of odds castling, the castling animation is off here. Is there any possible fix or circumvention? (2021-09-14)
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No. 792 HN
See also: P1323914 & P1388527
A.Buchanan: For clarity, I would write the stipulation as: "(a) White to play. Last move? (b) PG in 4.0" (2016-08-13, hidden)
A.Buchanan: See also: P1323914 (2021-04-14, hidden) more ...
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Anton Baumann: C+ Alybadix (2022-05-06, hidden) more ...
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Die Autoren schreiben:
Correction:
Problemkiste, Issue 91, Februar 1994, Seite 128, Abteilung Bemerkungen & Berichtigungen
"Nr. 3212 [sic!] v.Gruber/Müller: wie HG mitteilt muß die Bedingung "KAMIKAZE REX INCLUSIV" heißen, nicht Kamikaze-Circe rex inclusiv. Letzteres wäre nicht nur ein Zuviel an Bedingungen, sondern auch noch UL, weil da auch 31-steinige Stellungen möglich sind."
Dieser Eintrag wird also mit der Korrektur aktualisiert!
Erich Bartel: Das war ein schöner Tag am 21.8.1993 bei Hans Gruber zusammen mit Frank Müller und ich bedanke mich recht herzlich für die Widmung, die mir ausgezeichnet schmeckt, fast so gut wie der super delikate Original-Zwetschgendatschi von Hansens Mutter!!!(\eb) (2007-03-04)
A.Buchanan: I don't get this: please can someone explain (2020-12-09)
Henrik Juel: Under the Kamikaze-Circe condition, where both captured and capturing man are reborn after a capture, the initial game array is legal, but removing one man gives an illegal position, so the IGA is a legal cluster
I have no info about the super delicate original Zwetschgendatschi from Hansen's mother (2020-12-09)
A.Buchanan: Hi Henrik, please clarify the rules for the middle part. Why is e.g. 1. a4 b5 axb5[sBb7] with the white pawn disappearing because it can't be reborn on occupied b2? Is it because the rebirth square for capturer is taken to be the start square not the end square of the move? That seems unlikely because I read in PDB that promotion counts before capturer's rebirth. The other possibility is that capture is illegal if the capturer cannot be reborn, but that seems inconsistent with the spirit of Kamikaze. Normally in Circe, a captured piece doesn't come back if the rebirth square is occupied. That surely would still apply here. Glossary is silent on all this. Thanks! (2020-12-09)
Henrik Juel: I think you are right, Andrew, so the IGA is not a legal cluster under Kamikaze-Circe, and the problem is cooked
In the more serious matter at hand, Zwetschgendatschi means plum cake... (2020-12-09)
A.Buchanan: I can't believe that serious fairy heavyweights such as were engaged in this problem would have made something cooked. And I still don't know what K-C actually is. I will ask HG. Maybe he has some comments on plum cake too? :-) (2020-12-09)
A.Buchanan: Henrik has also been copied on an email from Hans Gruber which states in part:
"The problem by Frank and me (PDB: P1013968) is cooked - the intended solution does not work, because the initial game array is NOT a legal cluster under Kamikaze-Circe rex inclusive. Of course this was unavoidable, as dedication problems always are unsound. We should have known that before but did not see in-how-far we were wrong. It is good to learn about that a bit more than a quarter of a century after. I dare to state, without consulting Frank, that there will be no correction to the problem. The basic idea "initial game array = legal cluster" just does not work." (2020-12-09)
Arnold Beine: Perhaps the problem can be fixed by changing the fairy condition into "Platzwechselcirce rex inklusiv". Then every position with 31 pieces is illegal and the IGA should be legal. (2020-12-09)
Henrik Juel: The problem can probably be saved just by changing the condition to Strict Kamikaze-Circe RI (2020-12-09)
A.Buchanan: What is the exact rule for Kamikaze-Circe please? And how does strict differ? (2020-12-09)
Henrik Juel: In Kamikaze-Circe, as part of a capture, the capturer is reborn if its rebirth square is empty (otherwise it vanishes), and the captured is reborn if its rebirth square is empty (otherwise it vanishes). The rebirth squares are the standard Circe ones (based on the capture square).
Strict Kamikaze-Circe additionally stipulates that a capture is possible only when both rebirth squares are empty; so the piece count never changes (2020-12-09)
A.Buchanan: Thanks Henrik: that doesn't sound very "strict" Kamikaze, sounds like "no-sharp-edges video-game" Kamikaze, where no-one actually can get hurt :) Regular Kamikaze RI is trivially a legal cluster, no? And more interestingly, ordinary Kamikaze is a legal cluster too, because if just one piece is removed, that must have been captured by the *other* king, who is still stuck in his cage. That would be my suggested fix (2020-12-10)
Henrik Juel: Yes, any condition where 31 men cannot occur in a game would do
I chose strict K-C, because that was the most simple change to K-C (2020-12-10)
A.Buchanan: Strict K-C RI the number of pieces for each side must always be the same. K RX you can certainly have 31 pieces on the board but not in game array position. It’s still very simplistic but it’s a bit more subtle (2020-12-10)
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paul: The first S Ceriani-Frolkin is a Schnoebelen. (2020-11-03)
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Moldenhauer: Computerprüfung: C+ Stelvio 1.11 3 Sekunden.
Keine Lösung: BP 19.0, BP 19.5. (2023-05-01)
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paul: 11.Thg8 (2022-09-16)
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VL: Castling is illegal (W's last move). (2008-11-13)
Henrik Juel: so cooked by no solution (2023-12-12)
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Silvio Baier: 1.f4 d5 2.f5 Le6 3.f6 Sd7 4.fe f5 5.efL Se7 6.a4 Sc8 7.Ld6 Dh4 8.Lg3 0-0 9.a5 Tf6 10.a6 Tg6 11.ab Tg5 12.b8D g6 13.D:a7 Kg7 14.Da2 T:a2 15.Lf2 D:f2+
Rundläufe zweier Bauern mit anschließendem Schlag - damit auch Ceriani-Frolkin(DL); C+ (Euclide 0.95) (2010-02-16)
paul: QB Prentos theme (2020-11-29)
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paul: The first 7 moves tested by WinChloe in 2 hours. (2019-12-15)
Henrik Juel: Jacobi 0.7.5 in Heuristic and PG demolition mode did not find the intended solution using more than 10 hours
The best attempt was 1.a4 e6 2.a5 La3 3.bxa3-f8=L Sc6 4.Ld6 cxd6-e7 5.a6 Dc7 6.axb7-b5 La6 7.bxa6-b7 Sf6 8.bxa8-d8=S Kxd8-b7 9.h3 Kc8 10.h4 Kd8 11.h5
Note the natural notation of the Take&Make moves, far better than something like 3.bxa6[-wBa6,+wSa8], which should be written as 3.bxa6-a8=S (2021-10-23)
A.Buchanan: I will copy Gerd Wilts on your notation suggestion, which doesn't work quite now here but might be made to work - I agree it's superior. (2021-10-24)
Nightrider: What a pleasure to read this! I invented take&make, and I used the natural notation (like "bxa8-d8S") right from the beginning. Isn't it ideal if readers may understand the idea of a condition immediately by the notation of the moves?

By the way, the same holds for the (much more recent) condition make&take, where a move of a wSc3 that captures a bBg8 (for example) should be written analogously as S-f6xg8. Here again, does this natural notation not make clear on the spot what the basic idea of make&take is?

(And does it not look MUCH more elegant, for both conditions, if they are written in small letters exclusively and without blanks around "&" ? For me, it was always take&make and (years later) make&take. But, de gustibus non est disputandum...) (2021-10-24)
A.Buchanan: Hi Nightrider, thanks for kind words. I did email Gerd directly after the earlier post. He's pretty busy at the moment but in a few months thinks will have more time to deal with some items on the backlog.
For names, I agree that syntax varies. Sometimes it's down to taste, more often it's just random noise. There's also the question of "&" versus "and". (StrateGems uses both in one page!) In German, nouns are always capitalized, and the rest of PDB inherits that kind of uniformity, with the idea that PDB is just applying a local pattern, not trying to be authoritative in promoting a "canonical" way of writing each term. WinChloe has similar policy: Take & Make. YACPDB has Take&MakeChess. Search engines divide up words into atoms, so when I ask google for take&make I get "Take & Make" & "Take&Make" almost equally, so Google is blind to the distinct form that you prefer. Sorry. (2021-10-24)
Michel Caillaud: cooked using Jacobi demolition mode with constraints :
1.b4 c5 2.bxç5-ç4 d5 3.h3 Lg4 4.hxg4-c8=D Sc6 5.Dxa8-b8 Sf6 6.Dd6 exd6-d7 7.a3 Lb4 8.axb4-f8=L Dc7 9.Lb4 dxc4-ç5 10.Ta2 Kd8 11.Ta1 cxb4-e7 (2022-01-12, hidden) more ...
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SCHRECKE: C+, Gustav 4.1d, Brute Force (2021-11-13)
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Frank Müller: Korrektur in Springaren 08/1997, Seite 161: ser-Beweispartie in 53 mit wDa8 (2009-11-12)
paul: Author's solution: 1. b4 2. b5 3. b6 4. ba7 5. ab8=B 6. Ba7 7. Be3 8. Bg5 9. f4 10. Kf2 11. Kg3 12. Kh4 13. g3 14. Bh3 15. Bf5 16. h3 17. Rh2 18. Rf2 19. Rf3 20. Ra3 21. Rxa8 22. Ra4 23. Re4 24. a4 25. a5 26. a6 27. a7 28. a8=N 29. Nb6 30. Nxc8 31. Na7 32. Nc6 33. Nxd8 34. Ne6 35. Nxf8 36. Ng6 37. Nxh8 38. Ng6 39. Ne5 40. Ng4 41. Nh6 42. Nxg8 43. Nh6 44. Ng4 45. Ne3 46. Ng2 47. e3 48. Ne2 49. Nec3 50. Na2 51. c3 52. Qa4 53. Qa8# (2010-05-29)
paul: See P1007350 (2010-05-29)
Henrik Juel: I believe that the year should be 1997 (2022-09-30)
Mario Richter: Klären Stellung: In einer ser-BP sollte Weiß 16 Steine haben. (2009-11-12, hidden)
hpr: Hier schient sowieso was schiefgegangen zu sein, denn die Quelle ist auch nicht vollständig. Kann mal jemand bitte nachschauen?! (2009-11-12, hidden)
Frank Müller: Stellung berichtigt und Datum ergänzt. (2009-11-12, hidden) more ...
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Sobrecases: Specific try play:

1.Sf3? b5 2.b3 b4 3.Ba3 b×a3 4.b4 Bb7 5.S×a3?? B×f3 6.Rb1 Bc6 7.e4 a6 8.B×a6 Bb7 9.Rb3 Bc8 10. Rd3

4.?a6!? 5.S×a3 Bb7 6.Rb1 B×f3?? 7.Rb3 Bc6 8.e4 Bb7 9.B×a6 Bc8 10.Rd3 (2010-04-12)
paul: Jacobi+ (2022-11-12, hidden) more ...
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Moldenhauer: Computerprüfung: C+ Popeye 4.89 (16GB) 64Bit in 2 Min..
Keine Lösung: BP 33.5, 33.0. (2024-01-06)
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paul: No need of Schlagschach (same solution with orthodox rules) (2022-11-06)
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paul: Checked by Jacobi 0.7.5 (2021-02-09)
James Malcom: So C+? (2021-02-09)
James Malcom: I'll assume so. (2021-02-10)
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BUc2 m
SCHRECKE: C+, popeye 4.87 (2021-10-21)
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BUS20 E7b-B-L
SCHRECKE: C+, popeye 4.87 (2022-03-06, hidden) more ...
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SCHRECKE: C+, popeye 4.87 (2021-10-24)
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BUS20 IM LOT
SCHRECKE: C+, popeye 4.89 (2024-01-26, hidden) more ...
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LX8K TEB IM
vf: a1<>h1 mit identischen Quellenangaben (P1161471)
SCHRECKE: C+, Gustav 4.1d, Brute Force (2021-09-06)
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A12LL1 3m
SCHRECKE: C+, popeye 4.87 (2023-03-05, hidden) more ...
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RA2 e423 3m
A.Buchanan: I think this is the true original, not Haas 1976. It is basically the same whether L or B on 7th rank, whether K on d5 or e5, whether everything is shifted by files, whether (if L on 7th) board rotated. (2021-10-06)
Henrik Juel: I agree that P1142901 is anticipated by this problem
And this is also slightly more economical
Haas is not to blame, because the problem section in Skakbladet was not very prominent in 1970
I expect that Hilding tried to fool unwary solvers (2021-10-06)
Henrik Juel: Some old issues of Skakbladet are available at https://skakbladet.skak.dk/ (move the cursor to Arkiv at the top of the page), but issues from 1963 to 1999 are not (yet) available, so I cannot document the details of Hilding's problem (2021-10-06)
A.Buchanan: No worries about Haas or Skakbladet, Henrik. Like probably hundreds of others, Hilding's problem had the correct solution, but as marked neither as G="retro" nor k="No legal last move for Black". I've flipped a bunch of these tonight, but have run out of energy. (2021-10-06)
Henrik Juel: Thanks for your effort, Andrew (2021-10-06)
A.Buchanan: You're very welcome Henrik. Article 15 is my second favourite convention, so I am happy to have identified 146(!) in the last 24 hours that were lurking unrecognized in PDB. I was looking for g='2#' and sol='3.' so I also managed to fix typos etc in about 100 false positives. (2021-10-07)
Henrik Juel: My goodness me
I cannot handle even my old task of just testing; only thanks to Michael S, who is now doing the lion's share, we are just scraping by in the testing department
Tiny typo here in the try: 2.De6#, not 3. (2021-10-07)
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HB RU-LS
Anton Baumann: C+ Gustav 4.1d (2021-03-29)
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HB m
Henrik Juel: C+ Popeye 4.61 (2021-11-03, hidden)
Henrik Juel: solution
1.Th5 Kf4 2.Se2+ Ke4 3.Lg2+ Ke3,Kd3 4.Tc5 .. 5.Tc3#
2... Kf3 3.Kd2 g3 4.Th4 .. 5.Tf4#
2... Ke3 3.Lg2 Kd3,g3 4.Tc5 .. 5.Tc3# (2021-11-03, hidden) more ...
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(MZ712)
SCHRECKE: C+, Gustav 4.1d, Brute Force (2021-04-01, hidden) more ...
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B12L ASd5 m
SCHRECKE: C+, Gustav 4.2d, Brute Force (2024-03-23, hidden) more ...
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A12LL1 e405
SCHRECKE: C+, Gustav 4.2e, Brute Force (2023-11-08)
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T12-2 IM
vf: a1=a2, Dasni, Minimat, 1995;
c1=a1, Morgan, British Chess Magazine, 1969;
c) Speckmann, 1976, Mattaufgaben mit drei und vier Steinen
Alfred Pfeiffer: Genre: #2 (2010-09-14)
Felber, Volker: Schwalbe nur Teil a) (2011-09-20)
Henrik Juel: C+ Popeye 4.61 (2021-03-27)
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m20 RA2 FO3LS
Henrik Juel: C+ Popeye 4.61 after obvious analysis (2023-08-16, hidden) more ...
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E2-d2D2 m
SCHRECKE: C+, popeye 4.87 (2023-04-08)
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A18a1L
SCHRECKE: C+, popeye 4.89
1. Lf3! Kf8 2. Lh5 Ke8 3. Kg7# (2023-11-09, hidden) more ...
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François Labelle: Cooked by Jacobi:
5... Lg4 6.axa7 Lxe2 7.axb8=S Ta6 8.Sxa6 Lxa6 9.Txe7+ Dxe7+
The cook is also quickly found by Popeye when testing the last 4.5 moves with a=b4.5 (with every version of Popeye that I have installed). (2019-02-09)
paul: Actually, bpPh5 must be in f5, with 1. ...Pg7-f5 in solution. But still cooked: 1.dxd7+ exd7 2.hxh7 df5 3.hxg8=Q Be6 4.Qxh8 Qe7 5.Qxg7 Bxe2 6.Qxf7+ Kxf7 7.axa7 Bh6 8.axb8=S Ra6 9.Sxa6 Bxa6+. (2022-08-17)
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paul: H27, Album FIDE 2007-09 (2022-04-06)
paul: C+ (Euclide). La source est diagrammes 167/2008. (2011-07-03, hidden) more ...
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paul: Jacobi+ (2021-11-23, hidden) more ...
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Henrik Juel: The double CF is even double Prentos, as the promoted men are captured by officers (2018-12-29)
Henrik Juel: Natch 3.1 found the solution at pos. 2, but did not conclude in an hour
Stopped at pos. 850 (2018-12-29, hidden)
Henrik Juel: I let Natch run another hour, stopping at pos. 2090, still without conclusion (2018-12-29, hidden)
Moldenhauer: Computerprüfung: C+ Stelvio 1.4 08:35:12 Stunden. (hh:mm:ss)
Keine Lösung: BP 9.0. (2023-07-11, hidden) more ...
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SCHRECKE: C+, popeye 4.87 (2022-09-25, hidden) more ...
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SCHRECKE: C+, Gustav 4.1d, Brute Force (2021-10-13)
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Anton Baumann: C+ Gustav 4.2a (2024-01-24, hidden) more ...
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PR M.Caillaud: A Pronkin Rook. By nature, a Pronkin is a long travel by a Pawn. Many have been produced. In this one, guessing the theme from the diagram is not obvious.
Mario Richter: The award says "SPG 8,0", but since
1. a4 h5 2. Ta3 h4 3. Tg3 h3 4. Txg7 hxg2 5. Txg8 gxh1=D 6. Tg3 Dxg1 7. Th3 Dg2 8. Lxg2
does the job too, the problem is either cooked or the stipulation is something like "PG in exact 8.0". (2012-10-02)
Björn Enemark: A correction: with wRh3 at a5 and wBg2 at f1 there is no short solution.
1.a4 h5 2.Ta3 h4 3.Tg3 h3 4.Txg7 hxg2 5.Txg8 gxh1=T 6.Txh8 Txg1 7.Th5 Tg8 8.Ta5 Th8 (2012-10-21)
Moldenhauer: Computerprüfung: C+ Stelvio 1.0 1 Sekunde.
Keine Lösung: BP 7.0, BP 7.5, BP 8.5.
Notation 1. Zeile ist korrekt. (2023-02-21)
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paul: BB Ceriani-Frolkin, B Phoenix-Pronkin (2021-07-24)
Henrik Juel: Euclide 1.01 found the intended solution very quickly, and spent 41 minutes before reporting a unique solution
So the cooked label should be changed to C+ (2021-07-25, hidden) more ...
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Henrik Juel: Natch 3.1 made no visible progress for half an hour (2018-12-15)
paul: The first 16 moves tested by Jacobi (in about 10 hours) (2020-12-08)
hans: 1. d4 h6 2. Bg5 hxg5 3. h4 Rxh4 4. g4 Rxg4 5. Rh6 b5 6. Rb6 axb6 7. a4 Rxa4 8. Bg2 Raxd4 9. Ra6 Nxa6 10. b4 Nxb4 11. Bd5 Nxd5 12. f4 Nxf4 13. Qd3 d5 14. Qf5 Bxf5 15. c4 Bxb1 16. e4 dxe4 17. Nf3 Qd5 18. Ne5 Qxc4 19. Nd7 Kxd7 (2014-12-03, hidden) more ...
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Anton Baumann: C+ Gustav 4.1d (2021-03-19)
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Die Schwalbe 12/2013
MRi: "Nach dem ersten, naturgemäs schlaglosen Zug muss Weiß im Rest der Partie permanent schlagen. Dass sich gleich drei weiße Steine aktiv an dieser Fresserei beteiligen, kommt ebenso überraschend wie der Schnoebelen-Läufer auf h8, den man beim bloßen Blick auf die Endstellung wohl kaum erwartet hätte. Netter (Computer?!)-Fund im Bereich der At-Home-BPs."
HG: Siehe Kommentar zu 15609; hier mit Schnoebelen-Läufer, sK-Rückhehr und sD-Opferzug."
SBa zu 15069 und 15611: "Das dürften die ersten orthodoxen Doppelhomebase it Schnoebelenumwandungen sein. 156909 ist inbesondere weben des genialen Tempozugs Ke7, der die eigentliche Begründung der Umwandlung liefert, viel besser, die andere errinerte eher an Massakerbeweispartien, Nichesdestotrotz will das erstmal konstruiert sein.
A.Buchanan: @Mario: no computer: found by hand over the course of several evenings on a business trip to Mumbai, but I take the suspicion as a compliment! :D (2021-07-18)
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Version: f3 nach f4 -c2 a) 1.g1T+ Ke2 2.T*b1 a4 3.Tb8 Ta3 4.Tg8 Th3# b) wie oben
SCHRECKE: a)+b): C+, Gustav 4.2a, Brute Force (2022-04-21, hidden) more ...
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YM: 1° Recommandé (2021-10-20)
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Judge's comment [Kostas Prentos]: "This is not the first quadruple Pronkin in a proof game; Nicolas has published a few, already. It is the first time that one of the four thematic pieces, the wQ, is captured at home, and is replaced by a new Pronkin Queen. The promoted black Bishops are an effective, but unpleasant alternative to the standard method of doubled pawns that usually come with this theme. In this case, the capture on d1 is thematic, and that on a1, forgivable, considering that it takes 5 moves to reestablish the Rook on a1. On the plus side, all the surviving white army has resumed the initial position."
Henrik Juel: diagram error: black king is missing (2018-12-30)
Moldenhauer: Nach obiger Notation die
FEN: n7/b1p3p1/3qkn2/2p4b/b7/2br1rp1/P1PP2P1/RNBQKBNR
Diagramm müsste noch geändert werden! (2023-06-18)
James Malcom: Fixed. (2023-06-19)
Moldenhauer: Computerprüfung: C+ neue Stellung Stelvio 1.31
ursprüngliche FEN: n7/b1p3p1/2bqkn2/2p4b/b7/3r1rp1/P1PP2P1/RNBQKBNR keine Lösung!
neue FEN mit UPG Lösung 2 Min.: n7/b1p3p1/3qkn2/2p4b/b7/2br1rp1/P1PP2P1/RNBQKBNR
Jetzt muss jemand prüfen ob die ursprünglichen FEN falsch waren! Eingabefehler?
Diese Möglichkeit habe ich nicht. James kannst Du bitte? Danke!!!
Dann wäre noch das Diagramm auf die neuen FEN zu ändern.
Beim Start steht der Läufer noch auf c6. (2023-06-20)
James Malcom: Dug through the online The Problemist archive: https://www.theproblemist.org/mags.pl?type=tp
Issue 3/2011, p. 23.
The diagram now matches the publication and solution. (2023-06-20)
Henrik Juel: C+ Stelvio 1.13 (2023-06-20)
Henrik Juel: ... and no solution in 32.0 moves (2023-06-20)
Henrik Juel: should be Stelvio 1.31 of course, sorry (2023-06-20)
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correct version of P0555591
Viktoras Paliulionis: I changed to "after TR Dawson" because that's the usual heading for such cases in other sources and databases. All databases should use unified headings for problems. "Correction", "version", and "after ..." are different things. (2021-02-23)
Viktoras Paliulionis: The person who corrected the problem or submitted a version of it is not considered a co-author; the name of the first author with a note (version ..., or correction ...) should remain above the diagram. If the problem is sufficiently reworked (as this problem), only the new author is indicated with a note "after ...". (2021-02-23)
A.Buchanan: Hi Viktoras,
Thanks for your interest in this. Oh dear, there are several things to unpack here.
(0) I do follow the Codex as exactly as possible, however...
(1) The list of names above a PDB entry is NOT necessarily a list of equal co-authors. There is no separate PDB field to record the persons who correct or improve a problem. If the names only appear in other (pure text) fields, (a) you can't validate them against the author table and (b) you can't search for them properly. So the names at the top indicate only that these individuals were associated with the problem, and in all the problems which I've ever touched the "after" field then clarifies who did what, if that's necessary, e.g. "TRD, version GF".
(2) It was genuinely an "after TRD", then it's right that TRD wouldn't appear as a name at the top.
(3) However in this case, Geoff made the new version, and was also the magazine editor. If Geoff chose to show TRD the respect of publishing his new idea as a version, then we in PDB have absolutely no right to tamper with that. Similarly, there may be cases where we disagree with what the original author and the improver have agreed together, or what an improver has unilaterally decided. But in PDB we should just report what was actually published. If you feel strongly that a classification is inappropriate, take it up with the composers first rather than going behind their backs, as you apparently have here.
(4) In many cases there is a welcome blurring over time. If "PQ, version RS" exists, then what happens if TU comes along and makes a new version? I've never seen a situation of "PQ, version RS, version TU". Pickiness of fractional ownership just doesn't matter for these things. Particularly for retros, one often finds a bunch of names all together. It's essential that each names be there, but implying a tug-of-war for fractional ownership would just be too tedious, and people often don't bother. (2021-02-23)
Viktoras Paliulionis: Andrew, of course, the database must provide accurate information. My notes:
1. In Winchloe (Christian Poisson is always very accurate in presenting information), above the diagram of this problem it says: Jeffrey Foster, after Thomas R. Dawson, The Problemist 2017. Above diagram of problem Pxxxx is written: Thomas R. Dawson, correction A. Buchanan, The Problemist 1944 (v). (Note: correction: The Problemist Supplement 2017).
2. I think Christian Poisson is right, because in the magazine there is only one author listed above each diagram.
3. How can other people know that not only the author can be specified in the "author" field?
4. Associated individuals should be noted in some other fields, because problems can be reprinted (copy-pasted) in other sources with incorrect information.
5. Instead of "PQ, RS version, TU version", it should be "PQ, TU version".
6. "The correction should be published as a joint composition only if A agrees" (codex).
7. "Bunch of names all together" often occur when they all contribute to the creation together rather than after a single author’s publication. (2021-02-23)
Viktoras Paliulionis: Mentioned problem number is P1345892. (2021-02-23)
A.Buchanan: Sorry that this is long.
PDB is not WinChloe, which has a different data model, and unilateral decisions are made by one person.
PDB is looser, a shared artifact, and is under-documented. Fields and keywords are used in varying ways. In everything I have done I have aimed for an individual’s contributions to problems to be accessible fairly, never over-stating their role.
In PDB this can only be via the “a” field and then detailed annotation elsewhere in a text field. Sometimes in the past the “comment” field has been used by people foe this but I always use the “after” field. Otherwise it is impossible to track people’s involvement and this seems to me hugely unfair, far worse than some trivial confusion over roles for what are generally not earth-shaking problems.
Ideally there would be roles of “corrector”, “versioner” etc in PDB but that’s not the case, so we have to model things with what we have.
In any area of PDB data modelling (e.g. keywords), I try identifying stakeholders and their needs and interests, and how best to serve them. Here they are old and new composers, readers, searchers, etc.
It is of course not the case that PQ v TU would always be the answer. It depends. Your suggested approach is Procrustean - we need something softer and kinder here. :-) The rules in the Codex as specified are simply not scalable to multiple applications. This is independent of the fact that PDB does not represent these rules directly.
We are not talking about album-level problems usually, we are talking about the humble, organic sharing of constructions which to me is the lifeblood of chess problem composition particularly for the newcomers who I try to introduce to PDB from social media. Let’s not over-complicate! Thanks :-) (2021-02-23)
A.Buchanan: Sorry for length, but want a single place to log my current position.
I spend some time correcting cooked old problems which are otherwise of little interest. I enjoy the connection with history, and am scrupulous never to overstate my contribution (although personally I feel that a manual correction may sometimes be more worthy than one simply using without acknowledgement a computer program to trawl for optimal arrangements of pieces). I have an open request with YACPDB to recognize roles and dependencies in their data model. I have also requested through MatPlus that WFCC regularize the unsatisfactory Codex clause handling this area, however due to well-known disruptions in the world, this has not yet happened. It is particularly an issue where the original author is deceased. But other issues are (1) non-scalability of versions (2) unilateral "aftering" (3) lack of documentation of the implications of versioning (e.g. FIDE Album) (4) consistent annotation of versions (sources, dates) etc (5) knock-on effect that databases then don't have a clear model to implement.
A little shocked to read here that Christian Poisson apparently changed a published assignment from "TRD, v GF" to "GF, after TRD". This is not what the corrector (also the editor in this case) chose to publish. While I applaud Christian's terrific work over the years, I think this example shows why it's essential to have multiple databases, so that one perspective does not predominate, and that history is not rewritten. (2022-05-15)
A.Buchanan: Very unconvinced by Alfred pushing Geoff's name into "after" field. It's unhelpful for indexing. How can you even search on this field: it's missing from the FAQ examples list? Best to put all contributors into the main author field and then specifically state the dependency e.g. in the after field. As I had it before. (2018-01-22, hidden)
Henrik Juel: Solution
1... Lf4 2.Ke7 Lxc7 3.De8 Lf4 4.Kd8+ Le3 5.Le7 Lb6#
Ke8 and Dd8 switch place (2018-01-22, hidden)
Henrik Juel: C+ by Popeye 4.61 (2018-01-22, hidden)
A.Buchanan: And according to Alfred's editing, there are now two problems with the same original publication details, one of which is "reprinted" in the supplement. This is confusing and inaccurate. Original publication details should describe when *that* diagram appeared. As I had it before. (2018-01-22, hidden) more ...
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Vaclav Kotesovec: This problem was marked as C+, but I found a cook. (2023-03-31)
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Moldenhauer: Computerprüfung: C+ Popeye 4.90 (16GB) 1 Min. 48 Sek.
Keine Lösung: BP 9.5, 10.0. (2023-12-04, hidden) more ...
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Moldenhauer: Computerprüfung: C+ Popeye 4.90 (16GB) 1 Min. 24 Sek.
Keine Lösung: BP 9.5, 10.0. (2023-12-04, hidden) more ...
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Joost de Heer: 1. c4 Sc6 2. Qc2 Sd4 3. Qh7 Sb5 4. Qh4 Rh5 5. cxb5 Rc5 6. Qg5 Rc2 (2021-01-04)
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Cf: P1017659
paul: Verified by Jacobi with: stip ser-dia 31 forsyth rsbqkbsr/pppppppp/Q6R/P5RS/5PPK/2PPP1SP/1P5B/1B6 (2021-12-09)
Joost de Heer: This is probably Kriegspiel? If there are no black pieces, the knight path on moves 25/26 can go over f6 as well. (2022-10-25)
A.Buchanan: Good catch, Joost. The black units (because of bK) are necessary. I haven’t heard the term Kriegspiel used to describe this. (2022-10-25)
Henrik Juel: This is a series proof game (where only White moves, and he may not check with an intermediate move)
I see no relation to the fairy condition Kriegspiel (2022-10-25)
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James Malcom: Outbid by P1388480, with a whopping 7 consecutive castlings. (2021-04-13)
Anton Baumann: C+ Alybadix (2021-04-09, hidden) more ...
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A.Buchanan: For some reason this lovely problem had incorrectly been marked as cooked! (2021-10-08)
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Moldenhauer: Computerprüfung: C+ Stelvio 1.4 3 Sekunden.
Keine Lösung: BP 9.0 mit Stelvio 1.31 überprüft.
Notation: 1.e4 d5 2.exd5 Sc6 3.dxc6 Dd4 4.cxb7 Dxb2 5.d4 Dxa1 6.Lb2 Dxb2
7.d5 Db5 8.d6 Dd7 9.bxc8=T+ Dd8 10.d7# (2023-07-23)
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Hobacle: The problem of the last century! (2021-10-30)
James Malcom: Since no one has info on this, it is now apparent that Per Olin more than likely dreamt it up in the 70's and got confused over the years. See the new discussion in the above linked Matplus thread. it's not unlikely, since they did make P1368121, after all. (2021-01-05, hidden)
A.Buchanan: A charming problem. I’ve sent a list of 137 promotion-related keywords. We need to have some simple basic ones like promotion(T) not promotions, under-promotion, promotion to rook, promotion in forward play and many others. Particularly not a fan of under-promotion(T) which is self-redundant, vague and not meaningful concept for helpmate. It’s hard to imagine a keyword with more inherent defects. I won’t change it now because editing wars are unseemly. But please don’t dig the hole any deeper (2021-01-05, hidden)
James Malcom: Let's try and keep this to private channels, Andrew. (2021-01-06, hidden)
A.Buchanan: WinChloe with Rokagogo says 1.Rf7 é8=T 2.Rg6 Ré3(Té2) 3.Rh5 Rf4 4.Rh4 Th2‡ is the only answer. As with the Pam-Krabbe #3, I think we can be confident this is sound. Neat (2021-01-06, hidden)
James Malcom: Great! I underestimated Rokagogo, but I see it as true now. (2021-01-06, hidden) more ...
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SCHRECKE: NL in 5
Es fehlt sBd3! (2023-05-10, hidden)
Henrik Juel: C+ Popeye 4.61 (2023-06-30, hidden) more ...
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The task here is to maximize the number of necessary units in a homebase h#.
Henrik Juel: 1... e3 2.Da5 Df3 3.b6 Dxa8#
White (not Black) has no last move, so he has the move, and the stipulation is really h#2.5 (2020-09-23)
A.Buchanan: Can shift sBd7 to c7 for an entirely different mate, but alas one of sBg7h7 might be removed without losing soundness. (2020-09-24)
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Henrik Juel: C+ Popeye 4.61 (2020-09-25)
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Henrik Juel: C+ Popeye 4.61
1... Da1 2.Ke7 De5#
1.De7 Db1 2.Kd8 Db8#
1.Le7 Da1 2.Kf8 Dh8# (2020-09-25)
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Henrik Juel: C+ Jacobi 0.7.5
1.d4 Sf6 2.Bh6 Rg8 3.e3 Rah8 4.Qa6 Sxa6 5.Sd2 Rb8 6.O-O-O Rba8 7.Kb1 Sb8 8.Ba6 Rgh8 9.Sf1 Sg8 10.Be1
On a standard board Black would have made an even number of moves; not so here, with Ra8-h8-b8-a8 (2020-10-05)
A.Buchanan: This has exactly 200 solutions as a PG in 8.5, for example 1.d4 Sf6 2.Sd2 Sd5 3.e3 Sc3 4.Ba6 Sxd1 5.Sf1 Sc3 6.Bd2 Se4 7.O-O-O Sf6 8.Kb1 Sg8 9.Be1. It's restored to soundness if "genau" is stuck in the stipulation. (2021-06-10)
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