The trojan horse puzzle

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peter
Posts: 3186
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: The trojan horse puzzle

Post by peter »

Really nice, Arpad!
:)
The most exhilarating point to me is the complete nonchallance about Duals, or am I wrong about that?

Even if theoretically I'could imagine 1.Kb1 one move shorter to mate (my guess: #47) than the other possible King- moves, I wouldn't even be sure about it, not to mention were able to prove it, what does that matter at all, seeing it not as a mate in x- puzzle?

And I wouldn't call the theme cyclic Zugzwang, null move of course matters, but the main poblem is some kind of "lazy Knight"- eval together with better known lazy King, isn't it?
:)
Peter.
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Eelco de Groot
Posts: 4567
Joined: Sun Mar 12, 2006 2:40 am
Full name:   

Re: The trojan horse puzzle

Post by Eelco de Groot »

Uri Blass wrote:I can add that I was surprised to see it because I expected stockfish not to see it because of null move pruning and I know that stockfish cannot solve some very simple problems that all engines can solve because of null move pruning.

For example the following problem when stockfish suggests Ka2 and may be the only top engine in the world that cannot see that Kc1 is winning in a reasonable time.

[D]8/7p/5P1k/1p5P/8/P1p1p1p1/2P1P1P1/1K2b3 w - - 7 6
The difference is that in the original diagram there are only three pieces that can move, and you can add that kings and knights have limited range, that further limits it. There are many different paths to the same goal and they are all the same because the other pieces -in this case the pawns- do not add to the solution, don't move. So really a lot transposes. (And you only need a few entries in the pawn hash for the pawn formation.)

That everything transposes is also a problem, you get horizon effects because the knight does not know where to go if all the squares around him get the same high value. (I think it's something like this: if the knight or king can't make progress, -horizon effect- they may lose the information that got these squares to such high scores. In a next iteration they don't find the path, or take a longer than necessary path so the horizon shifts. Like those early computer chess games where every move seemed to win so the program never actually forced mate. I forgot what program.)

Like here where Ancalagon even loses the solution:

[pgn]
[Event "?"]
[Site "?"]
[Date "2017.09.15"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "3k4/8/7p/2p1p1pP/1pPpPpP1/1P1P1P2/N7/2K5 w - -"]

1. Kd2 Kd7 2. Nc1 Kc6 3. Ne2 Kd7 4. Ng1 Ke7 5. Nh3 Ke6
6. Nf2 Kd6 7. Nd1 Kd7 8. Nb2 Kc6 9. Na4 Kd6 10. Nb6 Ke6
11. Kc2 Ke7 12. Nd5+ Kf7 13. Nc7 Ke7 14. Nb5 Kd7 15. Kb2 *
[/pgn]
(After manually feeding Teemu's moves)
[D]8/4k3/7p/1Np1p1pP/1pPpPpP1/1P1P1P2/2K5/8 b - -
-----
48 16:02 +41.33 14...Ke6 15.Kd1 Kd7 16.Kc1 Ke7 17.Na3 Ke8 18.Nc2 Ke7 19.Kb1 Kd7 20.Kb2 Kc8 21.Ka2 Kb8 22.Ka1 Kc7 23.Ne1 Kb6 24.Ka2 Kb7 25.Kb2 Ka8 26.Kc2 Kb8 27.Kd2 Kb7 (24.522.120.493) 25471
48 16:02 +41.33 14...Kd7 15.Kc1 Kc6 16.Kb1 Kd7 17.Na3 Kc8 18.Nc2 Kd7 19.Ne1 Ke7 20.Kc1 Kd7 21.Kd2 Ke8 22.Ke2 Kf7 23.Ng2 Ke7 24.Kf1 Kd6 25.Kg1 Ke7 26.Nh4 gxh4 27.Kg2 Kd6 (24.522.120.493) 25471
48 16:02 +M18 14...Kf7 15.Nd6+ Kg7 16.Nf5+ Kh7 17.Kb1 Kg8 18.Nxh6+ Kg7 19.Nf5+ Kf7 20.Nd6+ Ke7 21.Nb7 Kf7 22.Nxc5 Ke7 23.Na6 Ke6 24.c5 Kf6 25.c6 Ke6 26.c7 Kd7 27.h6 Kc6 (24.522.120.493) 25471
48 16:02 +M18 14...Kf6 15.Nd6 Kg7 16.Nf5+ Kh7 17.Kb1 Kg8 18.Nxh6+ Kg7 19.Nf5+ Kf7 20.Nd6+ Kg7 21.Nb7 Kf7 22.Nxc5 Kf6 23.Na6 Kg7 24.c5 Kf6 25.c6 Ke6 26.c7 Kd7 27.h6 Kc6 (24.522.120.493) 25471
-----
49 17:10 +4.02 14...Ke6 15.Kc1 Kd7 16.Kd2 Ke6 17.Ke2 Kd7 18.Ke1 Ke7 19.Kf2 Ke6 20.Kf1 Kd7 21.Ke2 Ke6 22.Kd1 Ke7 23.Na7 Kd7 24.Kc2 Kc7 25.Kb1 Kd7 26.Nb5 Kc6 27.Kb2 Kd7 (26.148.190.398) 25373
48 17:10 +41.33 14...Kd7 15.Kb1 Ke7 16.Ka2 Ke6 17.Kb2 Ke7 18.Nc7 Kd7 19.Nd5 Ke6 20.Kb1 Kf7 21.Ka1 Ke6 22.Kb2 Kf7 23.Kb1 Ke6 24.Kc1 Kf7 25.Nc7 Ke7 26.Kd2 Kd7 27.Nd5 Ke6 (26.148.190.398) 25373
48 17:10 +M18 14...Kf7 15.Nd6+ Kg7 16.Nf5+ Kh7 17.Kb1 Kg8 18.Nxh6+ Kg7 19.Nf5+ Kf7 20.Nd6+ Ke7 21.Nb7 Kf7 22.Nxc5 Ke7 23.Na6 Ke6 24.c5 Kf6 25.c6 Ke6 26.c7 Kd7 27.h6 Kc6 (26.148.190.398) 25373
48 17:10 +M18 14...Kf6 15.Nd6 Kg7 16.Nf5+ Kh7 17.Kb1 Kg8 18.Nxh6+ Kg7 19.Nf5+ Kf7 20.Nd6+ Kg7 21.Nb7 Kf7 22.Nxc5 Kf6 23.Na6 Kg7 24.c5 Kf6 25.c6 Ke6 26.c7 Kd7 27.h6 Kc6 (26.148.190.398) 25373
-----
49 18:03 +4.02 14...Ke6 15.Kc1 Kd7 16.Kd2 Ke6 17.Ke2 Kd7 18.Ke1 Ke7 19.Kf2 Ke6 20.Kf1 Kd7 21.Ke2 Ke6 22.Kd1 Ke7 23.Na7 Kd7 24.Kc2 Kc7 25.Kb1 Kd7 26.Nb5 Kc6 27.Kb2 Kd7 (27.435.987.574) 25325
49 18:03 +4.19 14...Kd7 15.Kb1 Ke6 16.Kc1 Kd7 17.Kb2 Ke6 18.Nc7+ Kd7 19.Nd5 Ke6 20.Ka1 Kf7 21.Nb6 Ke7 22.Kb1 Ke6 23.Na4 Kd6 24.Kc1 Kc6 25.Kd2 Kd6 26.Ke2 Kc6 27.Kf2 Kd6 (27.435.987.574) 25325
48 18:03 +M18 14...Kf7 15.Nd6+ Kg7 16.Nf5+ Kh7 17.Kb1 Kg8 18.Nxh6+ Kg7 19.Nf5+ Kf7 20.Nd6+ Ke7 21.Nb7 Kf7 22.Nxc5 Ke7 23.Na6 Ke6 24.c5 Kf6 25.c6 Ke6 26.c7 Kd7 27.h6 Kc6 (27.435.987.574) 25325
48 18:03 +M18 14...Kf6 15.Nd6 Kg7 16.Nf5+ Kh7 17.Kb1 Kg8 18.Nxh6+ Kg7 19.Nf5+ Kf7 20.Nd6+ Kg7 21.Nb7 Kf7 22.Nxc5 Kf6 23.Na6 Kg7 24.c5 Kf6 25.c6 Ke6 26.c7 Kd7 27.h6 Kc6 (27.435.987.574) 25325
-----

Here Stockfish does not lose it and sees #30
[pgn]
[Event "?"]
[Site "?"]
[Date "2017.09.15"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[SetUp "1"]
[FEN "3k4/8/7p/2p1p1pP/1pPpPpP1/1P1P1P2/N7/2K5 w - -"]

1. Kd2 Kd7 2. Nc1 Kc6 3. Ne2 Kd7 4. Ng1 Ke7 5. Nh3 Ke6
6. Nf2 Kd6 7. Nd1 Kd7 8. Nb2 Kc6 9. Na4 Kd6 10. Nb6 Ke6
11. Kc2 Ke7 12. Nd5+ Kf7 13. Nc7 Ke7 14. Nb5 Kd7 (14... Ke6
15. Na3{diagram}) 15. Kb2 *[/pgn]

[D]8/8/4k2p/2p1p1pP/1pPpPpP1/NP1P1P2/2K5/8 b - -

Engine: Kaissa HT (512 MB)
by T. Romstad, M. Costalba, J. Kiiski, G. Linscott

101 440:53 +M30 15...Ke7 16.Kd1 Kd8 17.Nc2 Kc7
18.Ke2 Kd7 19.Kf2 Kc7 20.Ne1 Kd8
21.Kg2 Kd7 22.Kh3 Kd6 23.Ng2 Ke6
24.Nh4 gxh4 25.Kxh4 Kf6 26.g5+ hxg5+
27.Kg4 Kf7 28.Kxg5 Kg7 (619.081.078.790) 23402

101 440:53 +M30 15...Kf6 16.Kd1 Ke7 17.Nc2 Kd6
18.Ke1 Kd7 19.Kf2 Kc7 20.Ne1 Kd8
21.Kg2 Kd7 22.Kh3 Kd6 23.Ng2 Ke6
24.Nh4 gxh4 25.Kxh4 Kf6 26.g5+ hxg5+
27.Kg4 Kf7 28.Kxg5 Kg7 (619.081.078.790) 23402

100 440:53 +M30 15...Kd7 16.Kd1 Kc6 17.Nc2 Kc7
18.Ke2 Kd7 19.Kf2 Kc7 20.Ne1 Kd8
21.Kg2 Kd7 22.Kh3 Kd6 23.Ng2 Ke6
24.Nh4 gxh4 25.Kxh4 Kf6 26.g5+ hxg5+
27.Kg4 Kf7 28.Kxg5 Kg7 (619.081.078.790) 23402

best move: Ke6-e7 time: 440:53.250 min n/s: 23.402.830 nodes: 619.081.078.790
Debugging is twice as hard as writing the code in the first
place. Therefore, if you write the code as cleverly as possible, you
are, by definition, not smart enough to debug it.
-- Brian W. Kernighan
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Arpad Rusz
Posts: 273
Joined: Sat Apr 17, 2010 2:34 pm
Location: Budapest

Re: The trojan horse puzzle

Post by Arpad Rusz »

It seems that both 1.Kd2 and 1.Kb1 are equally good keys so I have corrected the study by modifying the position a bit:

http://ruszchessstudies.blogspot.hu/201 ... ess-3.html
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User avatar
MikeB
Posts: 4889
Joined: Thu Mar 09, 2006 6:34 am
Location: Pen Argyl, Pennsylvania

Re: The trojan horse puzzle

Post by MikeB »

latest dev-SF-McB

[d]8/7p/5P1k/1p5P/8/P1p1p1p1/2P1P1P1/1K2b3 w - - 7 1

Code: Select all

dep	score	nodes	time	(not shown:  tbhits	knps	seldep)
 51	  #18 	3.14G	1:14.14	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qc5+ Kg6 Qxb5 h4 Qd7 h3 Qxh3 Be1 a4 Bd2 a5 Bc1 a6 Kf7 Qf5+ Kg7 a7 Ba3 a8=Q Be7 Qe8 Bf6 Qfg6# 
 50	  #18 	3.07G	1:12.70	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qc5+ Kg6 Qxb5 h4 Qd7 h3 Qxh3 Be1 a4 Bd2 a5 Bc1 a6 Kf7 Qf5+ Kg7 a7 Ba3 a8=Q Be7 Qe8 Bf6 Qfg6# 
 49	  #19 	2.35G	0:56.31	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qg7+ Kf5 Qh6 h4 Qxh4 Ke6 Qh5 Be1 Kxe1 Kd7 Qxb5+ Kc7 Qd5 Kc8 a4 Kc7 a5 Kc8 a6 Kc7 a7 Kc8 a8=Q+ Kc7 Qdc6# 
 48	  #19 	1.87G	0:44.96	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qg7+ Kf5 Qh6 h4 Qxh4 Ke6 Qh5 Be1 Kxe1 Kd7 Qxb5+ Kc7 Qd5 Kc8 a4 Kc7 a5 Kc8 a6 Kc7 a7 Kc8 a8=Q+ Kc7 Qdc6# 
 47	  #19 	1.76G	0:42.19	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qg7+ Kf5 Qh6 h4 Qxh4 Ke6 Qh5 Be1 Kxe1 Kd7 Qxb5+ Kc7 Qd5 Kc8 a4 Kc7 a5 Kc8 a6 Kc7 a7 Kc8 a8=Q+ Kc7 Qdc6# 
 46	  #19 	1.67G	0:40.02	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qg7+ Kf5 Qh6 h4 Qxh4 Ke6 Qh5 Be1 Kxe1 Kd7 Qxb5+ Kc7 Qd5 Kc8 a4 Kc7 a5 Kc8 a6 Kc7 a7 Kc8 a8=Q+ Kc7 Qdc6# 
 45	  #19 	1.57G	0:37.62	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qg7+ Kf5 Qh6 h4 Qxh4 Ke6 Qh5 Be1 Kxe1 Kd7 Qxb5+ Kc7 Qd5 Kc8 a4 Kc7 a5 Kc8 a6 Kc7 a7 Kc8 a8=Q+ Kc7 Qdc6# 
 44	  #19 	1.55G	0:37.26	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qg7+ Kf5 Qh6 h4 Qxh4 Ke6 Qh5 Be1 Kxe1 Kd7 Qxb5+ Kc7 Qd5 Kc8 a4 Kc7 a5 Kc8 a6 Kc7 a7 Kc8 a8=Q+ Kc7 Qdc6# 
 43	  #19 	1.40G	0:33.56	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qg7+ Kf5 Qh6 h4 Qxh4 Ke6 Qh5 Be1 Kxe1 Kd7 Qxb5+ Kc7 Qd5 Kc8 a4 Kc7 a5 Kc8 a6 Kc7 a7 Kc8 a8=Q+ Kc7 Qdc6# 
 42	  #19 	1.40G	0:33.48	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qg7+ Kf5 Qh6 h4 Qxh4 Ke6 Qh5 Be1 Kxe1 Kd7 Qxb5+ Kc7 a4 Kd6 a5 Ke7 a6 Kf6 a7 Kg6 a8=Q Kg7 Qg5+ Kh7 Qag8# 
 41	  #19 	1.26G	0:30.18	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qg7+ Kf5 Qh6 h4 Qxh4 Ke6 Qh5 Be1 Kxe1 Kd7 Qxb5+ Kc7 a4 Kd6 a5 Ke7 a6 Kf6 a7 Kg6 a8=Q Kg7 Qg5+ Kh7 Qag8# 
 40	  #19 	1.20G	0:28.94	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qg7+ Kf5 Qh6 h4 Qxh4 Ke6 Qh5 Be1 Kxe1 Kd7 Qxb5+ Kc7 a4 Kd6 a5 Ke7 a6 Kf6 a7 Kg6 a8=Q Kg7 Qg5+ Kh7 Qag8# 
 39	  #19 	1.12G	0:26.97	Kc1 Bf2 Kd1 Bg1 Ke1 Kxh5 f7 Kg6 f8=Q Bf2+ Kf1 h5 Qe8+ Kh6 Qxb5 Be1 Kxe1 h4 Qf5 Kg7 a4 Kg8 a5 h3 Qxh3 Kf7 a6 Kg6 Qe6+ Kg5 a7 Kh5 a8=Q Kg5 Qad5+ Kf4 Qee4# 
 38	  #19 	1.09G	0:26.12	Kc1 Bf2 Kd1 Bg1 Ke1 Kxh5 f7 Kg6 f8=Q Bf2+ Kf1 h5 Qe8+ Kh6 Qxb5 Be1 Kxe1 h4 Qf5 Kg7 a4 Kg8 a5 h3 Qxh3 Kf7 Qf5+ Ke7 a6 Kd6 a7 Kc7 a8=Q Kd6 Qb8+ Ke7 Qbf8# 
 37	  #19 	1.07G	0:25.77	Kc1 Bf2 Kd1 Bg1 Ke1 Kxh5 f7 Kg6 f8=Q Bf2+ Kf1 h5 Qe8+ Kh6 Qxb5 Be1 Kxe1 h4 Qf5 Kg7 a4 Kg8 a5 h3 Qxh3 Kf7 Qf5+ Ke7 a6 Kd6 a7 Kc7 a8=Q Kd6 Qb8+ Ke7 Qbf8# 
 36	  #19 	1.05G	0:25.23	Kc1 Bf2 Kd1 Bg1 Ke1 Kxh5 f7 Kg5 f8=Q Bf2+ Kd1 h6 Qg7+ Kh5 Qf6 Kg4 Qxh6 Bg1 Qc6 Kf5 Qxb5+ Ke6 a4 Bf2 a5 Be1 Kxe1 Ke7 a6 Kf6 a7 Kg6 a8=Q Kg7 Qg5+ Kh7 Qag8# 
 35	  #20 	991.3M	0:23.88	Kc1 Bf2 Kd1 Bg1 Ke1 Kxh5 f7 Kg5 f8=Q h5 Qc5+ Kg6 Qxb5 h4 Qd7 Kf6 a4 Ke5 Kd1 h3 Qxh3 Kd6 Qh6+ Kc7 a5 Kd7 a6 Kc7 Qf4+ Kc6 a7 Kb7 Qb8+ Kc6 a8=Q+ Kd7 Qd8+ Ke6 Qad5# 
 34	  #21 	971.7M	0:23.41	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q h5 Qg7+ Kf5 Qh6 h4 Qxh4 Kg6 Qg4+ Kf6 Qh5 b4 axb4 Ke6 Qc5 Kf7 b5 Kf6 b6 Kg6 Qe5 Be1 Kxe1 Kh6 b7 Kg6 b8=Q Kh6 Qbh8+ Kg6 Qeh5# 
 33	  #23 	932.3M	0:22.45	Kc1 Bf2 Kd1 Bg1 Ke1 Kxh5 f7 Kg5 f8=Q h5 Qc5+ Kg6 Qxc3 h4 Qc6+ Kf7 Qxb5 Kf6 Qc6+ Ke5 Qd7 Bf2+ Kd1 h3 Qxh3 Kd5 Qh5+ Ke6 a4 Kd7 Qd5+ Kc7 a5 Bg1 Qb5 Bf2 a6 Kd6 a7 Ke7 a8=Q Be1 
 33	+126.12!	477.2M	0:11.31	Kc1! 
 33	+101.99!	457.8M	0:10.86	Kc1! 
 33	+82.69!	445.0M	0:10.56	Kc1! 
 33	+67.27!	409.2M	0:09.74	Kc1! 
 33	+54.95!	357.9M	0:08.53	Kc1! 
 33	+45.11!	348.9M	0:08.32	Kc1! 
 33	+37.25!	343.1M	0:08.18	Kc1! 
 33	+30.98!	335.5M	0:08.00	Kc1! 
 33	+25.98!	325.1M	0:07.75	Kc1! 
 33	+22.00!	295.9M	0:07.07	Kc1! 
 33	+18.82!	266.6M	0:06.37	Kc1! 
 33	+16.30!	249.0M	0:05.94	Kc1! 
 33	+14.30!	238.8M	0:05.70	Kc1! 
 33	+12.72!	215.2M	0:05.17	Kc1! 
 33	+11.47!	215.2M	0:05.17	Kc1! 
 33	+10.49!	189.4M	0:04.55	Kc1! 
 32	+9.50 	50.1M  	0:01.22	Kc1 Kxh5 f7 Kg6 f8=Q h5 Kd1 Bf2 Qe8+ Kg5 Qe5+ Kh6 Qh8+ Kg6 Qxc3 Kg5 Qc5+ Kg6 Qxb5 h4 Qc6+ Kf5 Qd5+ Kf6 Qd4+ Kg5 Qd8+ Kh5 Qd5+ Kg6 Qe4+ Kg7 Qxh4 Kg6 Qh3 Kf7 Qh5+ Ke7 Qh4+ Ke8 Qe4+ Kd8 Qd5+ Ke7 Qe5+ Kf7 Qf4+ Kg7 Qc7+ Kg6 
 31	+9.50 	40.9M  	0:01.01	Kc1 Kxh5 f7 Kg6 f8=Q h5 Kd1 Bf2 Qe8+ Kg5 Qe5+ Kh6 Qh8+ Kg6 Qxc3 Kg5 Qc5+ Kg6 Qxb5 h4 Qc6+ Kf5 Qd5+ Kf6 Qd4+ Kg5 Qd8+ Kh5 Qd5+ Kg6 Qc4 Kg5 Qd4 Kh6 Qf6+ Kh7 Qxh4+ Kg6 Qe4+ Kg7 Qd4+ Kf7 
 30	+9.50 	36.2M  	0:00.89	Kc1 Kxh5 f7 Kg6 f8=Q h5 Kd1 Bf2 Qe8+ Kg5 Qe5+ Kh6 Qh8+ Kg6 Qxc3 Kg5 Qc5+ Kg6 Qxb5 h4 Qe8+ Kg5 Qd8+ Kh5 Qf6 Kg4 Qg6+ Kf4 Qh5 h3 Qxh3 Ke5 Qh5+ Ke6 Qh6+ Ke5 Qc6 
 29	+9.50 	18.3M  	0:00.46	Kc1 Bf2 Kd1 Kxh5 f7 Kg6 f8=Q h6 Qg8+ Kf6 Qh7 Ke6 Qxh6+ Kd7 Qb6 Ke7 Qxb5 Kd6 Qd3+ Kc7 Qc4+ Kd7 Qc5 Ke6 Qh5 Kd6 Qb5 Kc7 Qd3 Kc6 Qxc3+ Kd6 Qc4 
 28	+9.50 	17.3M  	0:00.43	Kc1 Bf2 Kd1 Kxh5 f7 Kg6 f8=Q h6 Qg8+ Kf6 Qh7 Ke6 Qxh6+ Kd7 Qb6 Ke7 Qxb5 Kd6 Qd3+ Kc7 Qc4+ Kd7 Qxc3 Kd6 Qf6+ Kc5 Qg6 Kd5 Kc1 Kc5 Qh5+ Kb6 Qe5 
 27	+9.50 	16.3M  	0:00.40	Kc1 Bf2 Kd1 Kxh5 f7 Kg6 f8=Q h6 Qg8+ Kf6 Qh7 Ke6 Qxh6+ Kd7 Qb6 Ke7 Qxb5 Kd6 Qd3+ Kc7 Qc4+ Kd7 Qd4+ Ke7 Qxc3 Kd6 Qd4+ Kc6 Qe5 Kd7 Qf5+ Kc7 Kc1 Kb6 Qf6+ Kc5 
 26	+9.50 	15.1M  	0:00.38	Kc1 Bf2 Kd1 Kxh5 f7 Kg6 f8=Q h6 Qg8+ Kf6 Qh7 Ke6 Qxh6+ Kd7 Qb6 Ke7 Qxb5 Kd6 Qd3+ Kc7 Qc4+ Kd7 Qd4+ Ke7 Qxc3 Kd6 Qd4+ Kc6 Qe5 Kd7 Qc5 Ke6 
 25	+9.50 	12.1M  	0:00.30	Kc1 Bf2 Kd1 Kxh5 f7 Kg6 f8=Q h6 Qg8+ Kf6 Qh7 Ke6 Qxh6+ Kd7 Qb6 Ke7 Qxb5 Kd6 Qd3+ Kc7 Qxc3+ Kd6 Qd4+ Kc6 Qe5 Kd7 Qf6 Kc7 Kc1 Kc8 Qd6 Kb7 
 24	+9.50 	9.77M  	0:00.24	Kc1 Bf2 Kd1 Kxh5 f7 Kg6 f8=Q h6 Qg8+ Kf6 Qh7 Ke6 Qxh6+ Kd7 Qb6 Ke7 Qxb5 Kd6 Qd3+ Kc7 Qxc3+ Kd6 Qf6+ Kc5 Qe5+ Kc6 Qg7 Kc5 Qf6 Kd5 Kc1 Kc5 Qg6 
 23	+9.46 	8.69M  	0:00.22	Kc1 Bf2 Kd1 Kxh5 f7 Kg6 f8=Q b4 axb4 h6 Qg8+ Kf6 Qh7 Ke6 Qxh6+ Kd7 Qg7+ Kc8 Qxc3+ Kb8 Qe5+ Kc8 Qg7 Kb8 Qc3 Kb7 Qc5 Kb8 
 22	+8.77 	3.90M  	0:00.10	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q Kg6 Qe8+ Kf6 Qc6+ Kg7 Qxb5 h6 Qe5+ Kf7 Qh8 Kg6 Qxc3 Kf5 Qh8 Kg6 Qg8+ Kf6 Qh7 
 21	+8.67 	3.00M  	0:00.08	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q Kg6 Qe8+ Kf6 Qxb5 h6 Qc6+ Kg7 Qxc3+ Kg6 Qd3+ Kg7 Qd7+ Kg6 Qd6+ Kg5 Qd3 Kh4 Qc4+ Kg5 
 20	+8.64 	2.51M  	0:00.06	Kc1 Kxh5 f7 h6 f8=Q Kg6 Kd1 Bd2 Qg8+ Kf6 Qh7 Ke6 Qxh6+ Kd7 Qa6 Kc7 Qxb5 Kc8 Qc6+ Kb8 Qd6+ Kb7 Qxg3 Kc6 
 19	+8.63 	2.35M  	0:00.06	Kc1 Kxh5 f7 h6 f8=Q Kg6 Qg8+ Kf6 Kd1 Bd2 Qe8 Kg7 Qxb5 Kg6 Qc6+ Kh7 Qc7+ Kg6 Qd6+ Kg7 Qxg3+ Kf7 Qf4+ Kg6 Qe4+ Kg7 
 18	+8.60 	2.09M  	0:00.06	Kc1 Kxh5 f7 h6 f8=Q Kg6 Qg8+ Kf6 Kd1 Bd2 Qe8 Kg7 Qxb5 Kg6 Qc6+ Kh7 Qc7+ Kg6 Qd6+ Kg7 Qxg3+ Kf7 Qf4+ Ke8 Qxh6 Kd8 Qd6+ Kc8 
 17	+8.40 	1.90M  	0:00.05	Kc1 Kxh5 f7 Kg6 f8=Q h6 Qg8+ Kf6 Kd1 Bd2 Qe8 Kg7 Qxb5 Kg6 Qc6+ Kh7 Qc7+ Kg6 Qd6+ Kg7 Qxg3+ Kf7 Qc7+ Kg8 Qb8+ Kg7 Qd6 
 16	+8.21 	1.20M  	0:00.03	Kc1 Bf2 Kd1 Kxh5 f7 Kg6 f8=Q h6 Qe8+ Kg7 Qxb5 Kf6 Qc6+ Kg5 Qc5+ Kf6 Qxc3+ Kg6 Qe5 Kf7 Qh8 Kg6 Qg8+ Kf5 
 15	+8.05 	1.12M  	0:00.03	Kc1 Bf2 Kd1 Kxh5 f7 Kg5 f8=Q h5 Qg7+ Kf4 Qxc3 Kg5 Qc5+ Kg4 Qxb5 h4 Qb4+ Kg5 Qd4 Kh5 Qc5+ Kg4 
 14	+7.95 	713798	0:00.02	Kc1 Bf2 Kd1 Bg1 Ke1 Bf2+ Kf1 Kxh5 f7 Kg5 f8=Q Kg6 Qd6+ Kg5 Qc5+ Kg6 Qxb5 h5 Qd3+ Kg7 Qxc3+ Kf7 Qc4+ Kg6 
 13	  0.00 	38684  	0:00.00	Ka1 Bd2 Ka2 Bc1 Kb3 Bb2 Kb4 Bc1 Kb3 
 12	  0.00 	30186  	0:00.00	Ka1 Bd2 Ka2 Bc1 Kb3 Bb2 Kb4 Bc1 Kb3 
 11	  0.00 	23959  	0:00.00	Ka1 Bd2 Ka2 Bc1 Kb3 Bb2 Kb4 Bc1 Kb3 
 10	  0.00 	22522  	0:00.00	Ka1 Bd2 Ka2 Bc1 Kb3 Bb2 Kb4 Bc1 Kb3 
  9	  0.00 	20998  	0:00.00	Ka1 Bd2 Ka2 Bc1 Kb3 Bb2 Kb4 Bc1 Kb3 
  8	 -0.56 	14012  	0:00.00	Ka1 Bd2 Ka2 Bc1 Kb3 Bb2 Kb4 Ba1 
  7	 -0.96 	13019  	0:00.00	Ka1 Bd2 Ka2 Bc1 Kb3 Bb2 Kb4 
  6	 -1.29 	11012  	0:00.00	Ka1 Bf2 Ka2 Bg1 Kb3 Kxh5 
  5	 -1.01 	6779    	0:00.00	Ka2 Bd2 Kb3 Bc1 Kb4 
  4	 -2.11 	5244    	0:00.00	Ka2 Bd2 Kb3 Kxh5 
  3	 -1.49 	4183    	0:00.00	Ka2 Bf2 Kb3 
  2	 -2.15 	2993    	0:00.00	Kc1 Bf2 
  1	+7.35 	1538    	0:00.00	f7 Bd2 
  0	#
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peter
Posts: 3186
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: The trojan horse puzzle

Post by peter »

Arpad Rusz wrote:It seems that both 1.Kd2 and 1.Kb1 are equally good keys so I have corrected the study by modifying the position a bit:

http://ruszchessstudies.blogspot.hu/201 ... ess-3.html
Very well, Árpád, but what about 1.Ke1 now?
Here:
[d]7k/8/7p/2p1p1pP/1pPpPpP1/1P1P1P2/4K3/2N5 w - - 0 1

1. Ke1 Kg7 2. Ne2 Kf6 3. Ng1 Kf7 4. Nh3 Kf8 5. Nf2 Kf7 6. Nd1 Ke8 7. Nb2 Kd7 8. Na4 Kc6 9. Kd1 Kd6 10. Nb6 Ke7 11. Nd5+ Kf7 12. Nc7 Ke7 13. Nb5 Kd7 14. Na3 Kd615. Nc2 Kd7 16. Ne1 Ke8 17. Ng2 Kf7 18. Nh4

, I could spare one move to get to h4 with the Knight, the aim you reached at 19th in your .pgn. (Of course, the black King is on an other square)

Komodo 11.2.2 (NM switched off!) could have missed one more chance to force another triangle of the white King to get to b6 with the Knight, (even if I don't think so) or could have then a way to mate from 18th onward longer for one move or another one (again I don't think so), but even if so, that would make it just (about) the same Major Dual again, wouldn't it?
(I get #44 with 1.Ke1 and 45 with Kd2, but I can't prove this for sure.)

And then again, one move more or less in the one or the other one first move- solution wouldn't mean an thing anyhow in an non- mate- in- x- study, would it?

Nevermind, the Piece ist great anyhow, really would like to know the author
Peter.
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peter
Posts: 3186
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: The trojan horse puzzle

Post by peter »

peter wrote:...or could have then a way to mate from 18th onward longer for one move or another one (again I don't think so)
Maybe I have to stand corrected about that.
18.Kh4 already in my way after 1.Ke1 seems yet to cost even three moves later on to mate.
Moving the White King further to King's side before Nh4 makes the way to mate shorter for what you lose before seemingly, so I'm still at #44 with 1.Ke1 and #45 with 1.Kd2 till now., but I'm even less sure about that than before.

Anyhow, I'll go on trying to discriminate these two first moves of your version, Árpád, only if you think it matters for one (or two) moves longer or shorter to mate.
:)
Peter.
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peter
Posts: 3186
Joined: Sat Feb 16, 2008 7:38 am
Full name: Peter Martan

Re: The trojan horse puzzle

Post by peter »

peter wrote: [d]7k/8/7p/2p1p1pP/1pPpPpP1/1P1P1P2/4K3/2N5 w - - 0 1

1. Ke1 Kg7 2. Ne2 Kf6 3. Ng1 Kf7 4. Nh3 Kf8 5. Nf2 Kf7 6. Nd1 Ke8 7. Nb2 Kd7 8. Na4 Kc6 9. Kd1 Kd6 10. Nb6 Ke7 11. Nd5+ Kf7
:?:
Forget about that too, 11...Ke6 instead forces White's King to go to c1 before Na3 works.

Considering that 1.Ke1 yet seems to take just as long as 1.Kd2, 45 moves both, if I'm not wrong again this time.
:)
Peter.
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zenpawn
Posts: 349
Joined: Sat Aug 06, 2016 8:31 pm
Location: United States

Re: The trojan horse puzzle

Post by zenpawn »

Arpad Rusz wrote:[D]3k4/8/7p/2p1p1pP/1pPpPpP1/1P1P1P2/N7/2K5 w - - 0 1
GM Simon Williams recently made a video describing his thought process for solving this puzzle: https://www.youtube.com/watch?v=BSrsWJLRLgc
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Paloma
Posts: 1167
Joined: Thu Dec 25, 2008 9:07 pm
Full name: Herbert L

Re: The trojan horse puzzle

Post by Paloma »

Thanks, great Video :!:
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Paloma
Posts: 1167
Joined: Thu Dec 25, 2008 9:07 pm
Full name: Herbert L

Re: The trojan horse puzzle

Post by Paloma »

[pgn][Event "?"]
[Site "?"]
[Date "2017.09.26"]
[Round "?"]
[White "Trojan horse puzzle"]
[Black "Arpad Rusz"]
[Result "1-0"]
[Annotator "?"]
[SetUp "1"]
[FEN "3k4/8/7p/2p1p1pP/1pPpPpP1/1P1P1P2/N7/2K5 w - - 0 1"]
[PlyCount "52"]

1. Kb2 Kc8 2. Nc1 Kb7 3. Ne2 Kc7 4. Ng1 Kd7
5. Nh3 Ke7 6. Nf2 Kd6 7. Nd1 Kc6 8. Ka2 Kb6 9. Nb2 $2 {39#} (9. Nf2 $1 {25#}
Kc6 10. Nh3 Kd7 11. Nxg5 $1 Ke7 12. Nh3 Kf6 13. Kb1 {21#} Ke6 14. Nxf4+ exf4
15. Kc1 Kf6 16. Kd2 Kg7 17. e5 {17#}) 9... Kc6 10. Na4 {38#} Kd6 11. Nb6 Ke6
12. Nd5 {36#} Kf7 (12... Kd6 $2 13. Nf6 Ke6 14. Ng8) 13. Nc7 Ke7 14. Nb5 {34#}
Kd7 15. Na3 Kd6 (15... bxa3 16. Kxa3 {21#} Kc6 17. b4 cxb4+ 18. Kxb4 Kb6 19.
c5+ Kc6 20. Kc4 Kc7 21. Kd5) 16. Nc2 {32#} Ke6 17. Ne1 {32#} (17. Kb2 {31#})
17... Kf6 18. Ng2 Ke6 19. Kb2 Kf6 20. Kc2 Ke6 21. Kd2 Kf6 22. Ke2 Ke6 23. Kf2 {
26#} Kf6 24. Kg1 Ke6 25. Kh2 Kf7 26. Kh3 {23#} Kf6 (26... Ke6 27. Nh4 gxh4 (
27... Kf6 $2 28. Nf5 {16#}) 28. Kxh4 {21#} Kf6 29. g5+ hxg5+ 30. Kg4 Kf7 (30...
Kg7 31. Kxg5 {17#} Kh7 32. h6 {16#}) 31. Kxg5 {18#} Kg7 32. Kf5 Kh6 33. Kxe5
Kxh5 34. Kxf4 {15#}) 1-0

[/pgn]
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