Die Schwalbe

24 problem(s) found in 5200 milliseconds (displaying 24 problem(s)). [COMMENTDATE>=20200919 AND NOT K='Hilfsrückzüger' AND NOT K='Task (Konstruktion)' AND A='Petrovic, Nenad'] [download as LaTeX]

1 - P0001941
Nenad Petrovic
2nd International Team Match 1967-1970
3. (2.?) Platz
P0001941
(10+12)
Gewinn
AP
Henrik Juel: If White may castle, last move was g7-g5 to avoid retrostalemate. 1.fxg6ep followed by 0-0 to legitimize the en passant capture. (2004-09-23)
A.Buchanan: In V&V Encyclopedia, which I admire more for its scope than for its precision, this problem is given to illustrate "Petrovic Theme". The definition given is: "PETROVIC THEME Also called 'retroproblem of Petrovic Type'. Mutual dependence of en passant capture and castling. By playing an en passant capture other retro elements of position are legalized (usually castling)."
The definition makes no reference to A Posteriori. I am trying to get my head around the text here, because the e.p. does not "legalize" castling, rather it mandates it. I also encountered Öffner for this castling/e.p. AP (but not in V&V), but that might be someone's confusion in that Types Öffner vs Keym exist in PRA. (2022-02-15)
comment
Keywords: En passant as key, Castling (wk), a posteriori (AP) (Type Petrovic), En passant
Genre: Retro, Studies
FEN: b7/p4P2/2kbPp1p/3ppPp1/n3pp2/8/P1PPP2P/4K2R
Reprints: (2) Problem 141-143 08/1971
(77) Problem 144-147 12/1971
(C) Die Schwalbe 16 10/1972
Encyclopedia of Chess Problems 2012
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2022-02-15 more...
2 - P0001967
Nenad Petrovic
628 Sahovski vjesnik 1950
Dr. Fabel und Dr. Ceriani gewidmet
2. Preis
P0001967
(15+15)
Längste Beweispartie?
(AL: 1021,0)
1. S S 50. S b6 100. S h6 250. S h3 300. a3 S 450. a6 S 500. b3 S 550. g3 S 600. 0-0 S 649. S hxSg 699. h3 S 899. h7 S 949. axSb Ke8 950 Tf1 Kd8 951. Tg1 Ke8 952. Tf1 Dd8 1020. Kd1 Kd8 1021. De1 Ke8=
play all play one stop play next play all
Henrik Juel: Note that in problems castling acts like capture and pawn move with respect to the 50 moves rule. After 949.a6xSb7 there are 4 moves left by [Pa7]; but each camp can shift only KDT, on d1-g1 and b8-e8, respectively, so the triple repetition rule now limits the length of the game. (2004-09-09)
A.Buchanan: In some problems it's certainly the case that the 50-move rule operates incorrectly in this way. Such problems are fine, but obviously wouldn't want to impose this as a standard. Different composers can make different assumptions here (2023-06-20)
comment
Keywords: 50 move rule, Non-Unique Proof Game, Longest Proof Game, Castling
Genre: Retro
FEN: Nrq1kb2/1PpppppP/1p6/8/8/pP4P1/BRPPPPp1/BrnKQ1Rb
Reprints: (I) Problem 5-6 12/1951
Problem 7-9 03/1952
1439 FIDE Album 1945-1955 1964
(130) Problem 91-94 04/1964
Input: Gerd Wilts, 1995-06-03
Last update: A.Buchanan, 2012-04-08 more...
3 - P0564823
Nenad Petrovic
9645 FEENSCHACH 03-04/1970
P0564823
(2+10) C+
h#7
1. Kf8 Ta7 2. Ke8 Txa6 3. Kd7 Txa4 4. Kc6 Ta8 5. Kb5 Txc8 6. Ka4 Tc6 7. b5 Ta6#
play all play one stop play next play all
more ...
comment

Genre: h#
Computer test: C+ Gustav 4.1d
FEN: 2b3k1/1R6/pp6/2q5/pp6/bp6/1p6/1K6
Input: Markus Manhart, 1999-02-26
Last update: A.Buchanan, 2021-04-16 more...
4 - P1017733
Nenad Petrovic
Die Schwalbe 1930
P1017733
(15+10)
#2
1. hxg8=S
play all play one stop play next play all
BS Problemid: 2564
Authors: Petrovic, Nenad
Sources: FIDE Album (1914-1944) (I) 1971
Years: 1930
Henrik Juel: many duals (2021-09-24)
comment
Keywords: Brian Stephenson Collection (2564), Albino, Pickaninny, under-promotion key
Genre: 2#
FEN: n5r1/1B2pp1P/2KP1P1B/2p2b1R/1bP1k3/n1PNP1rR/1N4P1/7Q
Reprints: Die Schwalbe 48, p. 162, 12/1977
Input: Brian Stephenson, 2004-08-12
Last update: Dieter Berlin, 2021-09-24 more...
5 - P1028009
Nenad Petrovic
Vojko Bartolovic

Problemas 1963
1. Preis
Arguelles-Jubiläumsturnier
P1028009
(9+10)
#2
1. fxg3? droht 2. Dc4#, 1. ... Lxg3+!
1. f3? droht 2. Dc4#, 1. ... exd5!
1. f4? droht 2. Dc4#, 1. ... S6e5!
1. fxe3! droht 2. Dc4#, 1. ... S4e5!
1. dxc3? droht 2. Dxg4#, 1. ... b3!
1. d3? droht 2. Dxg4#, 1. ... Ta6+!
1. dxe3? droht 2. Dxg4#, 1. ... S4h6,S4~!
1. d4! droht 2. Dxg4#
1. ... Sh6,S4~ 2. Dxe3#
1. ... Sf4,S6e5 2. Sxf4,Sf4#
1. ... Ta6+ 2. Lxa6#
play all play one stop play next play all
SCHRECKE: 1. ... Sxf2 2. Dxe3,Tfe1# (Mattdual) (2023-03-04)
more ...
comment
Keywords: Brian Stephenson Collection (12893), Albino (zweifach)
Genre: 2#
FEN: 2B5/8/3Kp1n1/3N2P1/rp2Q1nb/2p1p1p1/3PkP2/3R1R2
Reprints: 139 FIDE Album 1962-1964 , p. 40, 1968
1621 Beispiele zur Ideengeschichte des Schachproblems , p. 328, 1982
27 Encyclopedia of Chess Problems , p. 19, 2012
Input: Brian Stephenson, 2004-08-12
Last update: Dieter Berlin, 2023-03-04 more...
6 - P1032240
Nenad Petrovic
Sahovski glasnik 06/1930
4./5. Preis geteilt
Ursic Gedenkturnier 1929
Jugoslavian Chess Federation
P1032240
(13+10) C+
#3
1. Sf4! droht 2. Sd3
1. ... Lg4 2. Sd5
1. ... Lf3 2. Se6
1. ... Le2 2. Sxe2
1. ... Lh5 2. Sxh5
play all play one stop play next play all
more ...
comment
Keywords: Brian Stephenson Collection (17146), Bivalve, Goethart-Thema, black self-obstruction
Genre: 3#
Computer test: Juel: Popeye 4.61
FEN: 8/nQ2R3/2q3PB/2p1n3/2P1k2N/p1P1P2P/r1rR2N1/bB1b2K1
Reprints: 60 Valves and Bi-Valves , p. 72, 1930
813 FIDE Album 1914-1944/II , p. 150, 1972
990 Beispiele zur Ideengeschichte des Schachproblems , p. 204, 1982
Input: Brian Stephenson, 2004-08-12
Last update: Dieter Berlin, 2024-03-17 more...
7 - P1035145
Nenad Petrovic
B version The Problemist 05/1946
P1035145
(9+3) C+
#2
1. Sb8 droht 2. Tbb1#,Tb2#,Tb3#,Tb4#,Tb5#,Tb6#,Th7#,Tg7#,Tf7#,Te7#,Td7#,Tb7#
1. ... Ta2xa1+ 2. Tb7-b1+
1. ... Ta2-a3 2. Tb7-b3+
1. ... Ta2-a4 2. Tb7-b4+
1. ... Ta2-a5 2. Tb7-b5+
1. ... Ta2-a6 2. Tb7-b6+
1. ... Ta2xa7 2. Tb7xa7+
1. ... Ta2-c2 2. Kd1xc2+
1. ... Ta2-d2+ 2. Kd1xd2+
1. ... Ta2xe2 2. Kd1xe2+
1. ... Th8xb8 2. Tb7xb8+
1. ... Th8-c8 2. Tb7-c7+
1. ... Th8-d8+ 2. Tb7-d7+
1. ... Th8-e8 2. Tb7-e7+
1. ... Th8-f8 2. Tb7-f7+
1. ... Th8-g8 2. Tb7-g7+
1. ... Th8xh6 2. Tb7-h7+

1. ... Ta2-b2 2. Tb7-b3+,Tb7-b4+,Tb7-b5+,Tb7-b6+,Tb7xb2+
1. ... Th8-h7 2. Tb7-c7+,Tb7-d7+,Tb7-e7+,Tb7-f7+,Tb7-g7+,Tb7xh7+
play all play one stop play next play all
innerhalb eines Artikels "Task Records" von N. Petrovic mit 4 neuen Zweizüger-Task-Rekorden. Das Originaldiagram war gespiegelt (r6B/6RP/P4N2/8/8/8/2QP3r/k3K2R), dann aber NL 1. 0-0+!

Petrovic: "B shows 16 variations from moves of two black rooks, the previous record being 15."
more ...
comment
Keywords: Brian Stephenson Collection (20074)
Genre: 2#
Computer test: The 16 thematic variations are OK by Popeye 4.61
FEN: B6r/PR6/2N4P/8/8/8/r3PQ2/R2K3k
Reprints: Neues Österreich 17/12/1950
32 FIDE Album 1945-1955 1964
Input: Brian Stephenson, 2004-08-12
Last update: A.Buchanan, 2022-02-28 more...
8 - P1035629
Albert Volkmann
Walther Jørgensen
Nenad Petrovic
Werner Issler
Karl Kaul
Geert Smit

8359 Die Schwalbe 04-05/1952
P1035629
(8+9) C+
#2
1. Sd6! droht 2. Sb7#
1. ... Sdc7 2. Ld2#
1. ... Sdb4 2. Sc4#
1. ... Sc3 2. Sb3#
1. ... Sde3 2. Dxb6#
1. ... Sf4 2. Dxa4#
play all play one stop play next play all
Konstruktionsaufgabe Nr. 5
SCHRECKE: C+, popeye 4.87 (2022-03-31)
comment
Keywords: Brian Stephenson Collection (20562)
Genre: 2#
Computer test: popeye 4.87
FEN: 2N5/K2B4/1p6/k2n2BR/r2Q3q/P2r4/2n3b1/2N3b1
Reprints: FIDE Album 1945-1955 1964
Input: Brian Stephenson, 2004-08-12
Last update: Dieter Berlin, 2022-04-27 more...
9 - P1044811
Nenad Petrovic
American Chess Bulletin 1955-1956
1/2 Preis
P1044811
(11+7)
#3

BS Problemid: 29816
Authors: Petrovic, Nenad
Sources: FIDE Album (1956-1958) 1961
Years: 1955-1956
Henrik Juel: C+ Popeye 4.61 (2021-11-05)
Henrik Juel: 1.Dg4 thr. 2.De2+ Kxd5 3.Dd3#
1... Kxd5/Lxc3/c5+/cxd5+ 2.Dd1/Sxc3/Sed6/Sfd6+ (2021-11-05)
comment
Keywords: Brian Stephenson Collection (29816)
Genre: 3#
FEN: 6Q1/Bn3N2/1rp4K/b2P1P2/2k1NR2/2P1p2p/1PP5/8
Reprints: FIDE Album 1956-1958 1961
2416 Problemista 213-215 01-03/1986
Input: Brian Stephenson, 2004-08-12
Last update: Marcin Banaszek, 2021-11-04 more...
10 - P1047421
Nenad Petrovic
Olympia-Turnier 1948
P1047421
(6+10)
#3
1. Tc3! g2 2. Tc1
1. ... f4 2. Txg3+
play all play one stop play next play all
Henrik Juel: dual 1... Df6 2.Dxf6,Txg3+ (2022-04-23)
comment
Keywords: Brian Stephenson Collection (32444), Stufenbahnung
Genre: 3#
FEN: 4K3/2p4p/2Qq2kr/3P1p1p/2R4p/6pN/p7/B7
Reprints: Problemschach [Sidler] , p. 13, 1968
Input: Brian Stephenson, 2004-08-12
Last update: Dieter Berlin, 2022-04-23 more...
11 - P1054330
Nenad Petrovic
The Problemist 15, p. 416, 05/1950
P1054330
(6+13)
#2
1. Kc6! droht 2. Sxa3#,Sd4#,Sd6#,Sxc7#,Sa7#,Sa2#,Sc2#,Sd5#
1. ... Tg1+ 2. Sd5#
1. ... Ta2+ 2. Sd5#
1. ... Tb2+ 2. Sd5#
1. ... Tc2+ 2. Sd5#
1. ... Td2+ 2. Sd5#
1. ... Te2+ 2. Sd5#
1. ... Tf2+ 2. Sd5#
1. ... Tgg8+ 2. Sd5#
1. ... Tg7+ 2. Sd5#
1. ... Tg6+ 2. Sd5#
1. ... Tg5+ 2. Sd5#
1. ... Tg4+ 2. Sd5#
1. ... Tg3+ 2. Sd5#
1. ... Th2+ 2. Sd5#
1. ... Sd4+ 2. Sxd4#
1. ... Sd5+ 2. Sd6#
1. ... Se4+ 2. Sd6#
1. ... Sg4+ 2. Sd6#
1. ... Sh5+ 2. Sd6#
1. ... Sh7+ 2. Sd6#
1. ... Sg8+ 2. Sd6#
1. ... Se8+ 2. Sd6#
1. ... Sd7+ 2. Sd6#
1. ... La5+ 2. Sc7#
1. ... Lb6+ 2. Sc7#
1. ... Lh2+ 2. Sc7#
1. ... Lg3+ 2. Sc7#
1. ... Lf4+ 2. Sc7#
1. ... Le5+ 2. Sc7#
1. ... Ld6+ 2. Sc7#
1. ... Ld8+ 2. Sc7#
1. ... Lb8+ 2. Sc7#
play all play one stop play next play all
'The Problemist': "MAXIMUM NUMBER OF CHECKS. The first problem with 27 chs. [P1392290] has held the record for nearly thirty years but the task expert now exceeds this number and brings it up to 32 in in a very neat setting. This second problem was sent to us in 1946 but has apparently not been published."
im FIDE-Album falsch mit sBf7 statt sBe7 nachgedruckt
Teppo Mänttä: Misprint. There must be a black Pawn e7 (instead of bl.Pf7). 1.Kc6!. (2021-07-28)
Henrik Juel: duals after 1... Tb8,Ta8,Dxe3,Sd6,Sxe3,d2,c2 (2021-07-29)
comment
Keywords: Brian Stephenson Collection (39377)
Genre: 2#
FEN: 2r5/1Kb1p3/B4n1q/1N3n2/RNk5/ppppP3/6r1/7b
Reprints: 272 FIDE Album 1945-1955 1964
Input: Brian Stephenson, 2004-08-12
Last update: Mario Richter, 2021-07-29 more...
12 - P1057791
Nenad Petrovic
? 1958
1. Preis
Gamage Memorial
P1057791
(14+14)
#3

BS Problemid: 42848
Authors: Petrovic, Nenad
Sources: Mat Plus 1994
Chess Problems: Introduction to an Art 1963
FIDE Album (1956-1958) 1961
Years: 1958
Henrik Juel: double threat 1.Df1 thr. 2.Sb6,Df5+
duals after 1... Sf2,Sh6
several mate duals (2021-11-05)
Henrik Juel: 1.Df1 thr. 2.Sb6,Df5+
1... Dxa2,Sxd2,Td3,e2,exd2 2.Df5+
1... Lf3,Lc1,Lh8,Lg7,Lf6,Le5 2.Sb6+
1... Lc3 2.Sf6+
1... Td3 2.Sxe3+
1... Txe8 2.fxe8=S thr. 3.Sxc7,Df7# (2021-11-05)
comment
Keywords: Brian Stephenson Collection (42848)
Genre: 3#
FEN: 4Rr2/BKp2P2/p1Pp2B1/3k3p/PpN1N1n1/r3p2Q/PbRP3P/qn5b
Reprints: Mat Plus 1958
2417 Problemista 213-215 01-03/1986
Input: Brian Stephenson, 2004-08-12
Last update: Marcin Banaszek, 2021-11-04 more...
13 - P1059873
Nenad Petrovic
De Maasbode 1946
3. Preis
P1059873
(14+8)
#3
Teppo Mänttä: The diagram position (= nr. 518 FIDE-Album 1914-1944/II) has NO SOLUTION. 1.a7? Txa7!, 1.a7? Tb1!, 1.a7? Tb2! 2.Thf5 Tb8+. (The position might be seriously misprinted!?). (2021-07-22)
Teppo Mänttä: The corrected version (= nr. 746 FIDE-Album 1945-1955), with a wh. Pawn a7 instead of wPa6, has the following solution: (Tries 1.Tff5? Tdxd2!, 1.Thf5? Sxc3!). 1.Kh7! (waiting) 1.--- Lb2 2.Tff5 ---/Txd2 3.Sf6#/Sxd2#, 1.--- Tb2 2.Thf5 ---/Sxc3 3.Sg5#/Sxc3#. But it is still damaged, since there is a DOUBLE REFUTATION in a thematical try: 1.Thf5?, 1.--- Sxc3! AND 1.--- Lxc3!. The double publication of this problem in two FIDE-Albums is really weird. (2021-07-22)
Teppo Mänttä: See P1064626 = the position with a white Pawn a7. (2021-07-22)
comment
Keywords: Brian Stephenson Collection (44943)
Genre: 3#
FEN: 7K/2p2R2/P1Pp4/2PN3R/3Pk2P/2Bp1NP1/r2Pn2P/b2r4
Input: Brian Stephenson, 2004-08-12
Last update: Marcin Banaszek, 2017-11-23 more...
14 - P1064626
Nenad Petrovic
De Maasbode 1946
3. Preis
P1064626
(14+8) C+
#3
1. Kh8-h7! zz
1. ... La1xc3 2. Sd5xc3+ Se2xc3 3. Tf7-f4#
1. ... La1-b2 2. Tf7-f5 droht 3. Sd5-f6#, 2. ... Td1xd2 3. Sf3xd2#
2. ... Se2-f4 3. Tf5xf4#
1. ... Td1-b1,Td~ 2. Tf7-f5 droht 3. Sd5-f6#, 2. ... Ta2xd2 3. Sf3xd2#
2. ... Se2-f4 3. Tf5xf4#
1. ... Td1xd2 2. a7-a8=D droht 3. Da8-e8#, 2. ... Ta2xa8 3. Sf3xd2#
2. ... Se2-f4,Sxd4 3. Tf7xf4#
1. ... Ta2xa7 2. Tf7-f5 droht 3. Sd5-f6#, 2. ... Td1xd2 3. Sf3xd2#
2. ... Se2-f4 3. Tf5xf4#
1. ... Ta2-a6,T~ 2. Tf7-f5 droht 3. Sd5-f6#, 2. ... Td1xd2 3. Sf3xd2#
2. ... Se2-f4 3. Tf5xf4#
1. ... Ta2xd2,Tc2 2. a7-a8=D droht 3. Da8-e8#, 2. ... Se2-f4,Sxd4 3. Tf7xf4#
1. ... Ta2-b2 2. Th5-f5 droht 3. Sf3-g5#, 2. ... Se2xc3 3. Sd5xc3#
play all play one stop play next play all
Teppo Mänttä: FIDE-Album gives the main variations 1.Kh7 Lb2/Tb2 2.Tff5!/Thf5! and the thematical tries 1.Tff5? Tdxd2!, 1.Thf5? Sxc3!. However, there is a double refutation 1.Thf5? Sxc3!/Lxc3!. To be compared with P1059873 (2021-07-22)
comment
Keywords: Brian Stephenson Collection (49717)
Genre: 3#
Computer test: Popeye 4.67
FEN: 7K/P1p2R2/2Pp4/2PN3R/3Pk2P/2Bp1NP1/r2Pn2P/b2r4
Reprints: 746 FIDE Album 1945-1955 1964
Input: Brian Stephenson, 2004-08-12
Last update: Marcin Banaszek, 2017-11-23 more...
15 - P1146586
Nenad Petrovic
883 Chess Life 05/03/1958
P1146586
(4+3)
#3
1. g8=T g2 2. Txg2 Kf3 3. 0-0#
play all play one stop play next play all
E2-c2 BUT30 FFS3
SCHRECKE: C+, popeye 4.87 (2022-12-11)
comment
Keywords: Miniature Collection (0051833), Promotion key (T), under-promotion (T)
Genre: 3#
FEN: 8/6P1/4R3/5p2/5k2/6p1/8/4K2R
Input: Felber, Volker, 2010-09-11
Last update: Rainer Staudte, 2022-12-11 more...
16 - P1156821
Nenad Petrovic
69 Mitteilungsblatt der Kieler SG 1974
1. Lob
P1156821
(4+1) C+
#3
1. Ld3! Ke5 2. Dc5+
1. ... Kd4 2. Da3 Kd5 3. Dd6#
1. ... Ke6 2. Dc7
play all play one stop play next play all
A10-34- 3m
more ...
comment
Keywords: Miniature Collection (0055620), Aristocrat, Miniature, Rex solus
Genre: 3#
Computer test: SCHRECKE: popeye 4.87
FEN: 2N5/8/8/3k1B2/8/8/5K2/2Q5
Input: Felber, Volker, 2010-09-12
Last update: Dieter Berlin, 2023-02-18 more...
17 - P1161171
Nenad Petrovic
864 The Problemist 05/1933
P1161171
(4+3) C+
#3
1. Df5+! Kg3 2. Df3+ Kh4 3. Th2#
1. ... Kh4 2. Th2+ Kg3 3. Dh3#
1. ... Tag4 2. Df3+ Kh4 3. Th2# 2. ... Tg3 3. Dh5#
1. ... Tgg4 2. Dh5+ Kg3 3. Dh2# 2. ... Th4 3. Df3#
play all play one stop play next play all
GG4
more ...
comment
Keywords: Miniature Collection (0324934), Miniature, Checking key
Genre: 3#
Computer test: SCHRECKE: popeye 4.87
FEN: 6r1/8/5K2/8/r7/3QP2k/5R2/8
Input: Felber, Volker, 2010-09-12
Last update: Dieter Berlin, 2023-02-18 more...
18 - P1165087
Nenad Petrovic
Norman Littlewood

19a Die Schwalbe 25-27, p. 476, 01/1967
2. Lob
P1165087
(5+1) C+
#3
1. d8=T! Kh7 2. e8=L Kg8 3. Lg6#
1. ... Kf5 2. e8=D Kg5 3. Td5#
play all play one stop play next play all
BUb2 BUT30
more ...
comment
Keywords: Miniature Collection (0058923), Miniature, Rex solus, under-promotion key (T), under-promotion (wL), Promotion (wD), Stalemate avoidance
Genre: 3#
Computer test: Juel: Popeye 4.61
FEN: 8/3PP1B1/6kP/8/8/6K1/8/8
Input: Felber, Volker, 2010-09-12
Last update: Dieter Berlin, 2022-11-25 more...
19 - P1223139
Nenad Petrovic
Sahovski glasnik 1930
Ursic-Memorial
2.-3. Preis geteilt
P1223139
(11+8)
#3
milan: +bPc6 1.Se3! M.Frelih (2023-09-01)
comment

Genre: 3#
FEN: 5R1K/1p6/1P6/2pN3R/1pn1k2P/2Pp1NB1/3Pn2P/3r4
Input: Felber, Volker, 2011-11-08
Last update: Felber, Volker, 2011-11-08 more...
20 - P1300865
Nenad Petrovic
Stella Polaris 10/1976
10. Thematurnier
Spezialpreis
P1300865
(8+13) C+
s#8
1. Kb8 h1=D 2. Lxh1 f4 3. Txf4 c1=D 4. Sxc1 f1=D 5. Sxf1 Sc7 6. Dxc7 a1=D 7. Lxa1 c5 8. Txc5 Ta8#
play all play one stop play next play all
Der Preisbericht erschien in Thema Danicum.
Anton Baumann: C+ Gustav 4.1d (2020-11-16)
comment

Genre: s#
FEN: n1KQ4/rp6/qpp5/kb2Rp2/7R/4N3/pBp1NpBp/8
Input: Frank Müller, 2015-04-04
Last update: Marcin Banaszek, 2020-11-18 more...
21 - P1312478
Nenad Petrovic
Problem 7, p. 109, 03/1952
P1312478
(9+4)
#2
Projective Chess
Solution:
1. Kg1!
1. ... Ke4,Kf3 2. D-PH#
1. ... d2,Kg4,Kg5 2. D-PD1#
1. ... Sc7~ 2. D-PV#
1. ... Sb6~ 2. D-PD2#

Non-solutions
1. D-PD2? Sc7a8,Sc7d5!
1. D-PH+? Kg5!
1. D-PD1+? Ke4!
1. Kh1,Kg2? Sb6a8,Sb6d5!
1. Kh3? Kf3!
1. h6? Kg5!
1. a3,a4,a7,d6,f6? Sb6~!
1. Dxb6,Dxc7,Dc6,Df2,Dg1,Db4,Da3? Ke5!
1. De5? Kxe5!
1. De3? Kxe3!
1. Dd4+ Kf3!
1. Db5,Dd5? SxD!
1. Da5? Sc7~! (the reason I think for wBa2a6)
play all play one stop play next play all
In der Lösung bezeichnet 'PH' das projektive Feld in horizontaler Richtung; 'PV' das projektive Feld in vertikaler Richtung; 'PD1' ist das projektive Feld in Richtung der Diagonale a1-h8; 'PD2' ist das projektive Feld in Richtung der Diagonale a8-h1.

A.Buchanan: Together with excellent paradoxical key, and the 4 clean mating lines, a large number of potential cooks are prevented quite economically (see non-solutions, above). wBf6 in particular has many roles. So on this occasion a minor dual at one point later in the solution seems completely acceptable. A very original composition!
Interessanterweise werden in der Lösung alle vier unendlich entfernten Felder des projektiven Schachbretts benutzt.
A.Buchanan: In projective geometry, every family of parallel straight lines intersects at an infinitely distant point. Chess problem composers in the former Yugoslavia have adapted this idea for the chessboard, adding four special squares “at infinity.”

Now a queen on a bare board, for example, can zoom off to the west (or east) and reach a square “at infinity” from which she attacks every rank on the board simultaneously from both directions. She might also zoom to the north (or south) to reach a different square at infinity; from this one she attacks every file simultaneously, again from both directions. Finally she can zoom to the northwest or southeast and attack all the diagonals parallel to a8-h1, or zoom to the northeast or southwest and attack all the diagonals parallel to a1-h8. These four “infinity squares,” plus the regular board, make up the field of play. (2015-11-20)
Henrik Juel: Fine explanation, Andrew, but I still need to see the intended solution (if you know it); this may also clarify the weird stipulation (2015-11-20)
Alfred Pfeiffer: Diese Schachvariante wurde 1952 von Prof. Lav Rajcic und Nenad Petrovic erfunden (D.B.Pritchard: The Encyclopedia of Chess Variants) (2015-11-20)
A.Buchanan: The articulate explanation is not mine: I found it at http://www.futilitycloset.com/?s=chess
I think one needs to add that only line pieces have the privilege to leave the regular board in this way. Which suggests another variant with Nightriders. Now there are another 4 squares accessible only by Nightriders. (2015-11-21)
Henrik Juel: Thanks, Andrew and Alfred
Nice key, but too bad about the trial after 1... Kg3 (2015-11-21)
Henrik Juel: Andrew has pointed out that the flaw after 1... Kg3 is only a dual (2015-11-22)
A.Buchanan: Someone asks me: is there a cook? 1. D-PD2 Sc7a8,Sc7d5 can be answered by 2. Kh3# (2020-11-10)
A.Buchanan: By the way: the squares at infinity are on a straight line, but that cannot be navigated by the queen. For suppose the contrary: then the direction of movement along that line would have to be parallel to some direction of movement of the queen, i.e. by symmetry parallel to *all* directions of movement of a queen, i.e. since lines parallel to one line are parallel to one another, we conclude that all lines on the board are parallel to one another. This is absurd, so the queen cannot navigate the line at infinity (2020-11-10)
comment
Keywords: Projective Chess, no 8x8 board
Genre: Fairies, Mathematics
FEN: 8/2n5/Pn1P1P2/2Q2P1P/2P2k2/3p4/P6K/8
Reprints: Matematika Na Shahmatnoi Doske
Schachmaty i matematika , p. 119, 1983
Schach und Mathematik [Gik] , p. 150, 1986
Input: A.Buchanan, 2015-11-20
Last update: A.Buchanan, 2020-11-10 more...
22 - P1390477
Nenad Petrovic
3925 Schach-Echo 9, p. 144, 08/05/1965
3. Preis
2. Thematurnier Schach-Echo 1964/65
P1390477
(11+4) C+
#3
1. Sxc4! Kxd5+ 2. Kd3
1. ... Kf5+ 2. Kf3
1. ... Kd4+ 2. Se3
1. ... Txh5 2. Dxe6+
play all play one stop play next play all
more ...
comment

Genre: 3#
Computer test: popeye 4.85
FEN: 8/4Q3/1PP1pB2/1P1Pr2P/2p1k3/P3N1P1/4K3/8
Input: Dieter Berlin, 2021-06-05
Last update: Alfred Pfeiffer, 2021-09-27 more...
23 - P1391108
Nenad Petrovic
The Hindu 1953
2. Preis
P1391108
(9+14) C+
#3
1. Le6! Df3/Dc2 2. Tb7+
1. ... Sc6 2. Td2+
1. ... Tgf1/Tgg3 2. Te2+
1. ... Db3/Tf3 2. Tg2+
play all play one stop play next play all
more ...
comment

Genre: 3#
Computer test: Popeye 4.61, except for a few mate duals
FEN: b6K/3B1N2/3P1kP1/n2p1P2/p3p1pp/p3N2r/1R6/B1bqn1r1
Reprints: 651 Deutsche Schachzeitung 8, p. 645, 05/1955
Input: Dieter Berlin, 2021-06-26
Last update: Alfred Pfeiffer, 2021-11-17 more...
24 - P1407870
Nenad Petrovic
Ligue d'Alsace des Echecs 1972-1973
1. Preis
P1407870
(4+13) C+
#3
1. Lb3! droht 2. La4+
1. ... Tg4 2. Kc8 ... 3. Sc7#
1. ... Tcf4 2. Dxf8+
play all play one stop play next play all
more ...
comment
Keywords: Line closing
Genre: 3#
Computer test: Juel: Popeye 4.61
FEN: 1n2kr2/2K1p1Qp/p2pN1n1/2p5/1pr5/5p2/B7/5b2
Reprints: 72 Schach ohne Partner [Grasemann] , p. 80, 1977
Input: Dieter Berlin, 2023-02-18
Last update: Dieter Berlin, 2023-02-18 more...
Show statistic for complete result. Show search result faster by using ids.

https://pdb.dieschwalbe.de/search.jsp?expression=COMMENTDATE%3E%3D20200919+AND+NOT+K%3D%27Hilfsr%C3%BCckz%C3%BCger%27+AND+NOT+K%3D%27Task+%28Konstruktion%29%27+AND+A%3D%27Petrovic%2C+Nenad%27

The problems of this query have been registered by the following contributors:

Gerd Wilts (2)
Markus Manhart (1)
Brian Stephenson (11)
Felber, Volker (5)
Frank Müller (1)
A.Buchanan (1)
Dieter Berlin (3)