Die Schwalbe

14 problem(s) found in 7106 milliseconds (displaying 14 problem(s)). [COMMENTDATE>=20220810 AND G='Retro' AND NOT K='Schnoebelen-Thema' AND S='Retros mailing list'] [download as LaTeX]

1 - P1001038
Andrew Buchanan
4v Retros mailing list 21/01/2001
P1001038
(14+1) C+
Last move?
#2
1. 0-0 Kxe2 2. Te1#
R: 1. Ke4-e3
play all play one stop play next play all
Die vorherige Stellung war noch nicht tot, wenn Weiß noch rochieren darf.
AB: First proof of "can castle", without recourse to conventions. (2009-11-22)
A.Buchanan: deadpos doesn't understand about retro logic yet, so does not eliminate R: 1. Ke4xLSBe3? (2022-11-13)
more ...
comment
Keywords: Dead Position, Castling, Rex solus (s), Obvious promotion (L), Last Move?, Type B
Genre: Retro, 2#
Computer test: HC+ Forward Popeye 4.79 DP deadpos
FEN: 8/7Q/8/4BB2/2PP1P2/3NkN2/PP2P1P1/4K2R
Reprints: 13 idee & form 156, p. 5284, 10/2022
Input: Gerd Wilts, 2001-01-25
Last update: A.Buchanan, 2023-12-27 more...
2 - P1004110
Olli Heimo
Retros mailing list 01/05/1997
1. ehrende Erwähnung Retro List Quick Composition Tourney
P1004110
(14+12) C+
BP in 25.0
1. g4 a5 2. Lg2 Ta6 3. Kf1 Th6 4. Lc6 bxc6 5. Kg2 La6 6. Kf3 Ld3 7. Ke3 Sa6 8. Kd4 Db8 9. Kc3 Db3+ 10. Kxb3 Kd8 11. Ka4 Kc8 12. b3 Kb7 13. Lb2 Kb6 14. Lc3 Kc5 15. Kxa5 Lg6 16. Kxa6 Kd5 17. Kb7 Ke4 18. Kc8 Kf4 19. Kd8 Kg5 20. Ke8 Kh4 21. Sf3+ Kh3 22. Kxf8 Kg2 23. Se1+ Kxh1 24. Ke8 Kg1 25. Kd8 Kf1
play all play one stop play next play all
Eingesandt unter dem Pseudonym "L. Strangebeast (aka Olli Heimonen)
Olli Heimo: Unto Heinonen has nothing to do with this problem. It was a quick composition tourney arranged by Ian Tinigodad and pseudonyms were allowed as certainly many of us noticed that Ian Tinigodad was a pseudonym and an anagram. Afterwards the correct names were picked up but for some unknown reason there is also Unto's name. Perhaps he has never seen the problem. Please remove his name. (2010-05-24)
Henrik Juel: Ian Tinigonad was an anagrammatic pseudonym for Gianni Donati, of course. (2010-05-28)
Moldenhauer: Computerprüfung: C+ Stelvio 1.0 05:18 Minuten.
Keine Lösung BP 24.0 und BP 24.5.
Notation ergänzen: 25.Kd8 Kf1 (2023-02-11)
comment
Keywords: Unique Proof Game
Genre: Retro
Computer test: Stelvio 1.0
FEN: 3K2nr/2pppppp/2p3br/8/6P1/1PB5/P1PPPP1P/RN1QNk2
Input: Gerd Wilts, 2002-06-09
Last update: Silvio Baier, 2023-03-02 more...
3 - P1011888
Michel Caillaud
Reto Aschwanden

Retros mailing list 31/12/2003
5. Preis
Gianni Donati 50th Jubilee Tourney
P1011888
(15+14) C+
BP in 24,5
1. c4 e5 2. c5 Ld6 3. cxd6 c5 4. Db3 c4 5. Dh3 c3 6. d3 c2 7. Ld2 c1=L 8. b4 Lb2 9. Sa3 Lc3 10. 0-0-0 g5 11. Le1 Ld2+ 12. Kb2 g4 13. Tc1 g3 14. Txc8 gxf2 15. Tc3 Dh4 16. g3 Sf6 17. Lg2 f1=L 18. e3 Le2 19. Sc4 Lf3 20. Se2 Tg8 21. Tf1 Tg6 22. Lh1 Lg2 23. Tf3 Lf1 24. Ka3 Lc1+ 25. Sb2
play all play one stop play next play all
Matching squares traced by the promoted Bishops! That this is managed without extra-set pieces is astounding. (PR Gianni Donati)
Cook: 1. c4 e5 2. c5 Ld6 3. cxd6 g5 4. d3 g4 5. e3 g3 6. Dg4 c5 7. Sc3 c4 8. Sa4 c3 9. Ld2 Sh6 10. 0-0-0 c2 11. b4 Tg8 12. Kb2 gxf2 13. g3 Tg6 14. Lg2 f1=L 15. Ka3 c1=L+ 16. Sb2 Le2 17. Le1 Ld2 18. Tc1 Sg8 19. Txc8 Lc1 20. Tc3 Lf3 21. Se2 Dh4 22. Tf1 Sf6 23. Lh1 Lg2 24. Tf3 Lf1 25. Dh3
Henrik Juel: an important keyword is missing: Donati theme
same in (some of) P1011889-P1011929 (2018-12-18)
Henrik Juel: Natch 3.1 found nothing in half an hour (2018-12-18)
Michel Caillaud: Reprint : H71 p.585, FIDE Album 2001-03

Cooked using Jacobi 0.7.5 with constraints :
1.c4 e5 2.c5 Ld6 3.cxd6 g5 4.d3 g4 5.e3 g3 6.Dg4 c5 7.Sc3 c4 8.Sa4 c3 9.Ld2 Sh6 10.0-0-0 c2 11.b4 Tg8 12.Kb2 gxf2 13.g3 Tg6 14.Lg2 f1=L 15.Ka3 c1=L+ 16.Sb2 Le2 17.Le1 Ld2 18.Tc1 Sg8 19.Txc8 Lc1 20.Tc3 Lf3 21.Se2 Dh4 22.Tf1 Sf6 23.Lh1 Lg2 24.Tf3 Lf1 25.Dh3

Correction : sTg6 to g4 (21...Tg4 instead of 21...Tg6 in the solution)
With the set of constraints used to uncork the cook, Jacobi 0.7.5 finds only the intended solution... (2021-09-20)
Michel Caillaud: The correction sTg6 to g4 was published in StrateGems 99 (p.138, sept. 2022)
It is C+ by Stelvio 0.93 (2022-12-18)
comment
Keywords: Unique Proof Game, Round Trip, Pure Round Trip (ll), Obvious promotion (l), Promotion (ll), Donati Theme
Genre: Retro
Computer test: Resolution time: Natch 3.3: ---, Euclide 1.11: ---, Stelvio 1.14: 15:10min
FEN: rn2k3/pp1p1p1p/3P1n2/4p3/1P4rq/K1RPPRPQ/PN2N2P/2b1Bb1B
Input: Gerd Wilts, 2004-01-01
Last update: Silvio Baier, 2023-08-15 more...
4 - P1011929
Nicolas Dupont
Retros mailing list 31/12/2003
Lob
Gianni Donati 50th Jubilee Tourney
P1011929
(10+15)
BP in 29,5
1. Sf3 e5 2. Sd4 exd4 3. Sc3 dxc3 4. h4 cxb2 5. Th3 bxa1=L 6. Tg3 Lb2 7. Tg6 hxg6 8. a4 Th5 9. a5 Txa5 10. h5 Ta1 11. h6 a5 12. hxg7 Sh6 13. g8=L a4 14. Lh7 a3 15. Lg8 a2 16. Lh7 L8a3 17. Lg8 Ke7 18. Lh7 Kd6 19. Lg8 Kc5 20. Lh7 Kb4 21. Lg8 c5 22. Lh7 Da5 23. Lg8 b6 24. Lh7 Lb7 25. Lg8 Lf3 26. Lh7 Sc6 27. Lg8 Te8 28. Lh7 Te4 29. Lg8 Se5 30. Lh7
play all play one stop play next play all
A six-fold oscillation by the theme Bishop, made necessary because no one else can move. Compare with Satoshi Hashimoto, Problem Paradise 1999. (PR Gianni Donati)
Silvio Baier: Kann noch nicht komplett getestet werden, aber die Version 12. h7 a4 13. hxg8=L a3 14. Lh7 a2 15. Lg8 La3 16. Lh7 Ke7 17. Lg8 Kd6 18. Lh7 Kc5 19. Lg8 Kb4 20. Lh7 c5 21. Lg8 Qa5 22. Lh7 b6 23. Lg8 Lb7 24. Lh7 Lf3 25. Lg8 Sc6 26. Lh7 Re8 27. Lg8 Te4 28. Lh7 Se5 29. Lg8 ist C+ (Stelvio 1.5) (2023-08-18)
comment
Keywords: Unique Proof Game, Pendulum (L x12), Round Trip, Non-standard material
Genre: Retro
FEN: 8/3p1p1B/1p4pn/q1p1n3/1k2r3/b4b2/pbPPPPP1/r1BQKB2
Input: Gerd Wilts, 2004-01-01
Last update: James Malcom, 2023-05-04 more...
5 - P1066742
Rustam Ubaidullajew
Retros mailing list 25/09/2004
1. Preis Sommerturnier 2003
P1066742
(8+12)
BP in 16,0
1. Sf3 d5 2. Tg1 d4 3. Sxd4 g5 4. Sb3 Dxd2+ 5. Lxd2 g4 6. Dc1 g3 7. Kd1 gxh2 8. Le1 h1=T 9. S1d2 Th2 10. Tb1 Txg2 11. Sa1 Txf2 12. Lg2 Txe2 13. Sf1 Txc2 14. Lxb7 Txb2 15. Lxa8 Txa2 16. Lh1 Td2+
play all play one stop play next play all
Moldenhauer: Computerprüfung: C+ Stelvio 1.4 in 17:01:03 Stunden.(hh:mm:ss) (2023-08-17)
comment
Keywords: Unique Proof Game, Phoenix (t), Interchange
Genre: Retro
FEN: 1nb1kbnr/p1p1pp1p/8/8/8/8/3r4/NRQKBNRB
Input: Gerd Wilts, 2004-09-30
Last update: Gerd Wilts, 2006-01-19 more...
6 - P1066749
Igor Vereshchagin
Rustam Ubaidullajew

Retros mailing list 25/09/2004
2. Lob Sommerturnier 2003
P1066749
(10+12) C+
BP in 13,0
1. Sc3 d5 2. Sxd5 Dxd5 3. Sf3 Dxa2 4. Tg1 Db1 5. Txa7 Dxc1 6. Txa8 Da1 7. Txb8 Da7 8. Da1 Dxf2+ 9. Kd1 Dxf1+ 10. Se1 Dxg1 11. Da8 Da7 12. Sf3 Da2 13. Sg1 Db1#
play all play one stop play next play all
Henrik Juel: Natch 3.1 did not find the solution in 2 hours (2018-12-19)
Moldenhauer: Computerprüfung: C+ Stelvio 1.0 30:26:23 Stunden. 3250955 Strategien.
Keine Lösung: BP 12.0, BP 12.5.
C+ Euclide 1.11 98:10:54 Stunden. (2023-02-15)
comment
Keywords: Unique Proof Game
Genre: Retro
Computer test: Stelvio 1.0
FEN: QRb1kbnr/1pp1pppp/8/8/8/8/1PPPP1PP/1q1K2N1
Input: Gerd Wilts, 2004-09-30
Last update: Silvio Baier, 2023-03-03 more...
7 - P1232272
Mark Kirtley
Retros mailing list 31/12/2003
4. Preis (version)
Gianni Donati 50th Jubilee Tourney
P1232272
(14+12) C+
BP in 23,5
1. a4 h5 2. a5 Th6 3. a6 Tc6 4. axb7 a5 5. bxc8=L a4 6. La6 Dc8 7. Lc4 Da6 8. Le6 Dd3 9. exd3 a3 10. Df3 a2 11. Df6 exf6 12. f4 Ld6 13. f5 Lxh2 14. Kd1 Le5 15. Th4 d6 16. Tb4 h4 17. Lc8 h3 18. Txb8 h2 19. Tb5 h1=T 20. Le6 Th2 21. Lc4 0-0-0 22. Td5 Kb7 23. La6+ Kb6 24. Lc8
play all play one stop play next play all
Cook: 1. a2-a4 a7-a5 2. f2-f4 b7-b5 3. Ke1-f2 h7-h5 4. Kf2-e3 Th8-h6 5. Dd1-e1 Th6-c6 6. a4xb5 a5-a4 7. De1-h4 a4-a3 8. Dh4-f6 e7xf6 9. Ke3-f2 Lf8-d6 10. b5-b6 Ld6-e5 11. b6-b7 d7-d6 12. b7xc8=L Dd8-d7 13. h2-h3 Dd7xh3 14. f4-f5 Dh3-d3 15. Th1-h4 a3-a2 16. Th4-b4 h5-h4 17. Tb4xb8 h4-h3 18. Tb8-b5 h3-h2 19. Tb5-d5 h2-h1=T 20. Lc8-a6 Th1-h2 21. La6-b5 0-0-0 22. e2xd3 Kc8-b7 23. Lb5-a6+ Kb7-b6 24. La6-c8 (Stelvio v0.93, RA)
The promoted white Bishop leaves its promotion square by a counterclockwise route. No sooner has it returned than it leaves again and retraces its steps, clockwise now! (PR Gianni Donati)

Correction of P1011887
Michel Caillaud: The correction found in the Winchloé database is with 14.Kd1 instead of 14.Kf2 and is C+ (Natch, Stelvio...) (2022-12-18)
comment
Keywords: Unique Proof Game, Round Trip, Pure Round Trip (L)
Genre: Retro
Computer test: Stelvio 1.0
FEN: 2Br2n1/2p2pp1/1krp1p2/3RbP2/8/3P4/pPPP2Pr/RNBK1BN1
Input: Dan Meinking, 2012-02-15
Last update: Silvio Baier, 2023-03-02 more...
8 - P1294321
Andrew Buchanan
www.anselan.com 2001
P1294321
(1+2)
Black to move. Last move?
R: 1. Kb8xSa8
play all play one stop play next play all
Compare P0001033.
Gerald Ettl: steht der sLh5 vielleicht auf h2 ?? (2023-07-02)
SCHRECKE: Why not R: Kb8xLa8? (2023-07-03)
Mario Richter: Wie "SCHRECKE" mit seiner Frage schon illustriert hat: mit dem sL auf h2 wäre das Problem inkorrekt, da neben R: 1. Kb8xSa8 auch R: 1. Kb8xLa8 als letzter Zug möglich gewesen wäre. Grund sind die etwas verwirrenden Dead-Reckoning-Regeln: mit sLh5 kann zuletzt nicht Kb8xLa8 geschehen sein, da in der Stellung wKb8 - sKb6 sLh5 sLa8 wegen der unzureichendes-Material-zum-Mattsetzen-Regel das Spiel schon in dieser Position beendet gewesen wäre, der wK als gar nicht mehr zur Ausführung eines Zuges geommen wäre ... (2023-07-03)
Mario Richter: Dear James, I suggest that you undo last change and put the black bishop back on h5! (2023-07-03)
A.Buchanan: There are 17 valid squares for the wB. Got to be on a light square for reasons given. Also it can't occupy or attack c8. And can't be attacking a8 because BTM. I think h5 selection was random, but could argue for any. (2023-07-04)
A.Buchanan: Or maybe bBa4, with which White by his last move avoided a completely sound #12. (2023-07-04)
Gerald Ettl: Dann waere es vielleicht ganz sinnvoll man schreibt die Bedingung unter das Diagramm. (2023-07-04)
A.Buchanan: Hi Gerald, it's not a condition, it's a FIDE rule since 1997, invented by a problemist who is also a rules committee member (Igor Vereschchagin) and approved by the rules committee (headed by FIDE Head International Arbiter Stewart Reuben), backed up by a WFCC convention since 2015 (Kjell Widlert & Michel Caillaud, responding to a request from some endgame studiers who understood that it was a real thing. Like 50M rule, it applies by default for retro problems. And the PDB keywords here give the game away anyway. If it was a forward stipulation, then I would indeed add a stipulation, e.g. P1208623. Please enjoy the madness that is DP rule :) P.S. I have found recently that it was really invented by Shakespeare. (2023-07-04)
Gerald Ettl: Ich spiele nicht nach den FIDE-Regel. (2023-07-04)
Olaf Jenkner: Allright.
https://www.skat-online.com/regeln-hilfe/regelwerk/internationale-skatordnung.html (2023-07-05)
comment
Keywords: Type B, Last Move? (KxS), Dead Position, Economy record (Last Move? Type B), Rex solus (W), Aristocrat, Miniature, Minimal
Genre: Retro
FEN: K7/8/1k6/7b/8/8/8/8
Reprints: Retros mailing list 20/02/2007
Input: A.Buchanan, 2015-01-07
Last update: James Malcom, 2023-07-03 more...
9 - P1380050
Eric Angelini
Retros mailing list 18/9/2020
P1380050
(12+10) C+
BP in 20.5
1. a4 d5 2. a5 d4 3. a6 d3 4. axb7 dxc2 5. bxc8=S cxd1=S 6. Sb6 Sf6 7. Sa4 Se4 8. h4 f5 9. h5 f4 10. h6 f3 11. hxg7 fxg2 12. Sf3 g1=S 13. g8=S Sxe2 14. Sxe7 Sa6 15. Sd5 Sb4 16. Ta3 Sa2 17. Txh7 Df6 18. Txc7 Th3 19. Tc2 Lb4 20. Sd4 Tc8 21. Sb5
oder auch (Non-Unique Proof Game)
1. Sf3 Sa6 2. Sd4 Sb4 3. Sb5 Sf6 4. a4 Se4 5. Ta3 Sa2 6. a5 d5 7. a6 d4 8. axb7 d3 9. bxc8=S dxc2 10. Sb6 Tc8 11. Sa4 cxd1=S 12. h4 f5 13. h5 f4 14. h6 f3 15. hxg7 fxg2 16. g8=S g1=S 17. Sxe7 Sxe2 18. Sd5 Lb4 19. Txh7 Df6 20. Txc7 Th3 21. Tc2
play all play one stop play next play all
The fastest way to control a square 16 times

Superseded by P1381619
James Malcom: Eric pondered this question yesterday on the list and on Stack Exchange. After a bit, I came back with one in 25.5 moves, my best effort, and Eric beat it today with this. A fun challenge to compose. This game is surely optimal! (2020-09-18)
Henrik Juel: This game may well be a shortest game to reach the aim
Three men never moved to control c3, but it might be possible to find a game in 20.0 moves leading to a position, where c6 or f6 are controlled 16 times (2020-09-18)
James Malcom: I severely doubt that it can be done on c6 is 20.0, as there is no tempo to switch the parity with. But I'll look into such a game on f6. (2020-09-18)
Moldenhauer: Computerprüfung: C- oder Cooked Stelvio 1.5 in 1 Sekunde.
Keine Lösung: BP 20.0. Figurenstellung sieht einem "a" ähnlich. Angelini?
Notation: 1.Sf3 Sa6 2.Sd4 Sb4 3.Sb5 Sf6 4.a4 Se4 5.Ta3 Sa2 6.a5 d5 7.a6 d4
8.axb7 d3 9.bxc8=S dxc2 10.Sb6 Tc8 11.Sa4 cxd1=S 12.h4 f5 13.h5 f4 14.h6 f3
15.hxg7 fxg2 16.g8=S g1=S 17.Sxe7 Sxe2 18.Sd5 Lb4 19.Txh7 Df6 20.Txc7 Th3 21.Tc2 (2023-08-31)
comment
Keywords: Non-Unique Proof Game, Non-standard material (SSss), Promotion (SssS)
Genre: Retro
Computer test: Moldenhauer: Stelvio 1.5 Keine Lösung: BP 20.0
FEN: 2r1k3/p7/5q2/1N1N4/Nb2n3/R6r/nPRPnP2/1NBnKB2
Input: James Malcom, 2020-09-18
Last update: Olaf Jenkner, 2023-09-03 more...
10 - P1381619
Michel Caillaud
Retros mailing list 18/9/2020
P1381619
(12+13) C+
BP in 19.5
1. f4 h5 2. f5 h4 3. f6 h3 4. fxe7 hxg2 5. exf8=S Th6 6. Sh7 a5 7. Sc3 a4 8. e4 a3 9. e5 axb2 10. e6 b1=S 11. e7 Sxd2 12. Sh3 Se4 13. Sf2 f6 14. Sg4 Kf7 15. Dxd7 Ta6 16. Dd4 Sd7 17. e8=S gxf1=S 18. Sd5 Sfg3 19. Lg5 Sh5 20. Tf1
play all play one stop play next play all
The fastest way to control a square 16 times

Superseding of P1380050
Olaf Jenkner: Der Vorläufer wurde gekocht. Kann diese Aufgabe geprüft werden? (2023-08-31)
Moldenhauer: Computerprüfung: C- oder Cooked Stelvio 1.5 in 1 Sekunde.
Keine Lösung: BP 19.0.
Stelvio-Notation: 1.Sc3 a5 2.Sf3 Ta6 3.Se5 a4 4.Sg4 a3 5.e4 axb2 6.e5 b1=S 7.e6 Sxd2
8.f4 Se4 9.f5 h5 10.Lg5 Th6 11.f6 h4 12.fxe7 f6 13.exf8=S h3 14.e7 Kf7 15.Dxd7 hxg2
16.Dd4 Sd7 17.Sd5 gxf1=S 18.e8=S Sfg3 19.Tf1 Sh5 20.Sh7.
Bitte Olaf! (2023-09-01)
A.Buchanan: This problem and its antecedant are NOT cooked. They are non-unique proof games, and there is no intention of uniqueness. Whilst it's useful to identify a shortest solution, it is disrespectful and confusing to wave around the terms "C-" & "cooked". When we have verified that this problem has no solution in 18.0 or 18.5 moves, we can mark it as C+. (2023-09-02)
Olaf Jenkner: That's quiet confusing. See P0000404 with stipulation "BP in 45,0". The keyword is "Unique Proof Game".
This problem has the stipulation "BP in 19.5". The keyword is "Non-Unique Proof Game".
I don't believe that the dot makes the difference. (2023-09-03)
Henrik Juel: One way of limiting the confusion is to change the stipulation to
Length of shortest proof game?
C+ then means that this length is indeed 19.5 moves (2023-09-03)
A.Buchanan: A root problem is that animation engine reads the stipulation to decide what to do. (AND the details are undocumented.) So if we change the stipulation to something correct, we will lose the animation. Also, there is no Originalforderung field to keep track of the composer's intent. The comma dot is another linguistic challenge which could be addressed if we had multi-language support for stips like we do for source, composer, keyword & fairy piece. Obviously I'm very grateful for Gerd's work, but he has given no indication when, if ever, he will restart serious development work on PDB, so in the meantime we need to muddle through. In the meantime, the best we could do is rework the stipulation to add "(non-unique)" or "how many solutions?" etc. This edit can be done by screen-scraping in an automated way, if we can agree the principle (2023-09-03)
more ...
comment
Keywords: Non-Unique Proof Game, Non-standard material (SSss), Promotion (SSss), Move Length Record
Genre: Retro
Computer test: Moldenhauer: Stelvio 1.5 Keine Lösung: BP 19.0
FEN: 2bqN1n1/1ppn1kpN/r4p1r/3N2Bn/3Qn1N1/8/P1P4P/R3KR2
Input: James Malcom, 2020-11-07
Last update: Olaf Jenkner, 2023-09-03 more...
11 - P1384480
Unto Heinonen
Retros mailing list 1997
1. Preis
Retros Mailing List Quick Comp. Tourney
P1384480
(14+15) C+
BP in 25,0
1. b2-b3 Sg8-h6 2. Lc1-b2 Sh6-f5 3. Lb2-f6 h7-h6 4. Lf6-g5 h6xg5 5. Sb1-a3 Th8-h3 6. Dd1-b1 Th3-g3 7. h2xg3 Sb8-c6 8. Th1-h6 Sc6-a5 9. Th6-c6 b7xc6 10. Ke1-d1 Lc8-a6 11. Kd1-c1 Dd8-b8 12. Kc1-b2 Ke8-d8 13. Kb2-c3 Kd8-c8 14. Db1-b2 Kc8-b7 15. Ta1-e1 Kb7-b6 16. Sa3-c4 Kb6-c5 17. Kc3-d3 Db8-b4 18. Kd3-e4 Sa5-b7 19. Ke4-f3 Kc5-d5 20. Sc4-e5 La6-c4 21. Kf3-g4 Kd5-e6 22. Kg4-h3 Ke6-f6 23. Se5-d3 Kf6-g6 24. Kh3-h2 Kg6-h7 25. Kh2-h1 Kh7-h8
play all play one stop play next play all

Duplicate Diagram: P1001277

LaTeX-import:
Source not uniquely identified: Internet-Retroliste
Michel Caillaud: The position, to be found at https://www.janko.at/Retros/RML/1997/N00-Awards.htm, is with wTe1 instead of wTd1
The source is 1. Preis, Retros-List Quick Comp. Tourney, Retros List 1997
The problem is C+ (Natch, Stelvio...) : solution as given by Henrik except 15.Ta1-e1
The position with wTd1 is indeed cooked (cook using 0-0-0) (2022-12-18)
more ...
comment
Keywords: Unique Proof Game
Genre: Retro
Computer test: Stelvio 1.0
FEN: r4b1k/pnppppp1/2p5/5np1/1qb5/1P1N2P1/PQPPPPP1/4RBNK
Reprints: Retros mailing list 1997
Input: fs/hg, 2020-12-30
Last update: A.Buchanan, 2024-01-31 more...
12 - P1405422
Eric Pichouron
Retros mailing list 25/09/2004
3rd Honorable Mention
Summer Tourney 2003/2004
P1405422
(11+10) C+
PG in 13.0
1. a4 h5 2. a5 h4 3. a6 h3 4. axb7 hxg2 5. h4 a5 6. h5 a4 7. h6 a3 8. h7 a2 9. hxg8=S axb1=D 10. Txa8 Dxc1 11. Txb8 Da1 12. Txc8 Dxc8 13. bxc8=L gxf1=T+
play all play one stop play next play all
Henrik Juel: C++ Euclide 1.01
Euclide found the solution quickly and spent som 25 minutes to verify uniqueness
Here C++ means that Euclide found no solution in 12 or 11 moves
The testing times could have been reduced by utilizing that last move must be g2xLf1=T+ almost certainly (2022-10-30)
A.Buchanan: Thanks Henrik - unique PG in 13.0 implies there is no PG in 11.0. For comprehensive check of short solutions it suffices to check deltas 0.5, 1.0 & 1.5. Normally these are way easier to check than the intended length. And if there’s check in the final position as here, then half the tests are free! Is that C+++ in your notation? :) (2022-10-31)
Henrik Juel: No, Andrew, I think that C++ suffices (2022-10-31)
more ...
comment
Keywords: Unique Proof Game, Allumwandlung
Genre: Retro
Computer test: C++ Euclide 1.01
FEN: 2B1kbNr/2ppppp1/8/8/8/8/1PPPPP2/q2QKrNR
Input: A.Buchanan, 2022-10-30
Last update: A.Buchanan, 2022-10-31 more...
13 - P1407174
Noam D. Elkies
Retros mailing list 01/01/2023
P1407174
(16+16) C+
PG in 10.0
How many solutions?
1. e4 e5 2. Ke2 Df6 3. Kd3 Db6 4. h4 d6 5. Th3 Sd7 6. Kc4 Le7 7. Te3 Sf8 8. Kd5 Lf6 9. Lc4 Ld7 10. Se2 Se7# for example
play all play one stop play next play all
2023 solutions
Henrik Juel: Surely, there are 2023 solutions
But how do you compute it? (2023-01-08)
Moldenhauer: Computerprüfung: C+ Jacobi v0.7.6 beta1 Lösungen: 2023 sind bestätigt!
Wie kommt man auf sowas? Interessiert auch mich. (2023-01-09)
A.Buchanan: White & Black play are almost independent. Because Black's first move is e5, wK route is determined. It's nearly C(10,3), but wRd3 would block e2-e4, so subtract one solution to make 120-1 = 119 = 7x17. Black's play is nearly as simple: C(9,2) fails due to collision on f8 3 times, and due to collision on f6 1 time, so 21-3-1 = 17. Note the final move is checkmate, a signature flourish that Noam likes to apply (2023-01-09)
comment
Keywords: Path enumeration (year), Non-Unique Proof Game, Capture-free
Genre: Retro, Mathematics
Computer test: C+ Jacobi v0.7.6 beta1 Lösungen: 2023 sind bestätigt!
FEN: r3kn1r/pppbnppp/1q1p1b2/3Kp3/2B1P2P/4R3/PPPPNPP1/RNBQ4
Input: A.Buchanan, 2023-01-08
Last update: A.Buchanan, 2024-01-02 more...
14 - P1407176
Andrew Buchanan
Retros mailing list 01/01/2023
P1407176
(16+0)
ser-PG in 19
How many solutions?
1. a4 2. Ta3 3. d4 4. h4 5. Thh3 6. Thf3 7. Tf6 8. f4 9. f5 10. Lf4 11. e3 12. Lc4 13. Ld5 14. c4 15. Db3 16. Db6 17. b4 18. Tb3 19. b5 for example
play all play one stop play next play all
2023 solutions
Joost de Heer: See Problemas april 2023 for a detailed explanation on how to calculate the number of solutions. (2023-04-04)
A.Buchanan: Hi Joost thanks for the comment. This problem basically is about "triangle + triangle = square", but the article uses a different mechanism (Elastic Belt) to reach the same number (2023-04-05)
comment
Keywords: Path enumeration (year), Seriesmover, Non-Unique Proof Game
Genre: Retro, Mathematics
FEN: 8/8/1Q3R2/1P1B1P2/P1PP1B1P/1R2P3/6P1/1N2K1N1
Input: A.Buchanan, 2023-01-08
Last update: A.Buchanan, 2023-08-27 more...
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