Interesting FEN

[MOBMAT]

I ran across a chess related YouTube video where the title is "Chess Engines Can't Find This Checkmate".
<sigh>
here is the video
https://www.youtube.com/watch?v=xe-9nn7cy2w

[d]

I searched my list of positions and didn't seem to have it, so edited it in Arena and had a lot of engines take it on.

The take away is that most engines will settle on bxa4 which leads down a long rabbit hole of stagnant results, but if an engine can go deep enough, some do find the move mentioned in the article, Qf6+. This queen sac eventually leads to a 4 pawn advantage but FAR from finding any mates.

Someone with a mega-system is free to give it a shot as it would be days on my meager hardware.

Sometimes the chess engine click bait titles drive me crazy.
I haven't seen a chess author (not engine author) who knows what they are talking about when it comes to engines and search capabilities.

I've been away for some time, what happened with the FEN to diagram capabilities?

Vin

[MOBMAT]

Ok, I re-watched the video and did some analysis. The video author indicates it is a mate in 10, but of course that is ONLY IF back doesn't sacrifice its queen on the second move and makes the not so ideal response. Well, duh, mates are easy when the opponent blunders! By sac'ing the queen black guarantees a very long game even after having to give up a rook for a Knight or Bishop.

Actually, engines do see the move, if you set Multi PV to 2. But that second best move will never be played.

It is like the Plaskett's Puzzle described here.

https://en.wikipedia.org/wiki/Plaskett%27s_Puzzle

Sure, it is a shorter mate when black doesn't play optimally, but author's use that as an excuse to say, engines can't solve this. Well, they can, but the solution is a deeper mate that takes a heck of lot long.

Ok, off my soap box! LOL

Vin

[Jouni]

First position is very easy Lc0 don't even consider other moves:

Analysis by Lc0 v0.30.0-dag:

35.Qf6+ Bxf6 36.gxf6+ Qxf6 37.exf6+ Kxf6 38.Bg5+ Kg7 39.Bh6+ Kg8 40.Bxf8 axb3 41.Be7 bxa2 42.Nxa2 Re8 43.Bf6 Nb8 44.Rxh7 Kxh7 45.Rh3+ Kg8
+- (4.72) Depth: 15/20 00:00:00 11kN
35.Qf6+ Bxf6 36.gxf6+ Qxf6 37.exf6+ Kxf6 38.Bg5+ Kg7 39.Bh6+ Kg8 40.Bxf8 axb3 41.Be7 bxa2 42.Nxa2 Re8 43.Bf6 Nb8 44.Rxh7 Kxh7 45.Rh3+ Kg8
+- (4.77) Depth: 15/22 00:00:00 12kN
35.Qf6+ Bxf6 36.gxf6+ Qxf6 37.exf6+ Kxf6 38.Bg5+ Kg7 39.Bh6+ Kg8 40.Bxf8 axb3 41.Be7 bxa2 42.Nxa2 Re8 43.Bf6 Nb8 44.Rxh7 Kxh7 45.Rh3+ Kg8
+- (4.81) Depth: 15/22 00:00:00 12kN
35.Qf6+ Bxf6 36.gxf6+ Qxf6 37.exf6+ Kxf6 38.Bg5+ Kg7 39.Bh6+ Kg8 40.Bxf8 axb3 41.Be7 bxa2 42.Nxa2 Re8 43.Bf6 Nb8 44.Rxh7 Kxh7 45.Rh3+ Kg8 46.Rh8#
+- (5.16) Depth: 15/23 00:00:01 14kN
35.Qf6+ Bxf6 36.gxf6+ Qxf6 37.exf6+ Kxf6 38.Bg5+ Kg7 39.Bh6+ Kg8 40.Bxf8 axb3 41.Be7 bxa2 42.Nxa2 Re8 43.Bf6 Nb8 44.Rxh7 Kf8
+- (5.20) Depth: 15/24 00:00:02 14kN
35.Qf6+ Bxf6 36.gxf6+ Qxf6 37.exf6+ Kxf6 38.Bg5+ Kg7 39.Bh6+ Kg8 40.Bxf8 axb3 41.Be7 bxa2 42.Nxa2 Re8 43.Bf6 e5 44.Rxh7 Kxh7 45.Rh3+ Kg8 46.Rh8#
+- (6.13) Depth: 15/24 00:00:05 19kN

[Ajedrecista]

Hello:

[...]

I searched my list of positions and didn't seem to have it, so edited it in Arena and had a lot of engines take it on.

[...]

The position is very similar than after 18.- Bb7 in Asauskas 1—0 Malisauskas (Vilnius, 2004):

[d]r2q1r2/1b2bpkp/p3p1p1/2ppP1P1/7R/1PN1BQR1/1PP2P1P/4K3 w - - 4 19

[pgn][Event "LTU-ch"]
[Site "Vilnius"]
[Date "2004.04.23"]
[EventDate "2004.04.23"]
[Round "1"]
[Result "1-0"]
[White "Henrikas Asauskas"]
[Black "Vidmantas Vaclovich Malisauskas"]
[ECO "B90"]
[WhiteElo "2358"]
[BlackElo "2525"]
[PlyCount "47"]

1. e4 c5 2. Nf3 d6 3. d4 Nf6 4. Nc3 cxd4 5. Nxd4 a6 6. Bc4 e6
7. Bb3 Be7 8. g4 O-O 9. g5 Nfd7 10. Rg1 Nc5 11. Be3 Nxb3
12. axb3 Nc6 13. Nxc6 bxc6 14. e5 d5 15. Ra4 g6 16. Rh4 c5
17. Rg3 Kg7 18. Qf3 Bb7 19. Qf6+ Bxf6 20. gxf6+ Kg8 21. Rxh7
Kxh7 22. Rh3+ Kg8 23. Bh6 Qc7 24. f4 1-0[/pgn]

As noted in a Fishcooking thread.

The position of the video has been mentioned several times at TalkChess, just searching the FEN (without the side to move, etc.) in the search engine of the forum. The earliest match was in 2010:

10 beautiful testpositions!!

------------------------

[...]

I've been away for some time, what happened with the FEN to diagram capabilities?

[...]

Regarding the display of chess diagrammes, there are some threads about it, like the next one:

How do we post FEN positions so as to see the diagram?

Regards from Spain.

Ajedrecista.

[Jouni]

Thanks, I remember there was another similar looking position. The another takes longer

Analysis by Lc0 v0.30.0-dag:
19.Qf6+ Bxf6 20.gxf6+ Kg8 21.Rxh7 Kxh7 22.Rh3+ Kg8 23.Bh6 Qc7 24.f4 Qe7 25.fxe7 Rfe8 26.Bg5 f5 27.exf6 Bc6 28.Nd1 e5 29.fxe5 Bd7
+- (2.28) Depth: 10/22 00:00:05 4kN
19.Qf6+ Bxf6 20.gxf6+ Kg8 21.Rxh7 Kxh7 22.Rh3+ Kg8 23.Bh6 Qc7 24.f4 Qe7 25.fxe7 Rfe8 26.Bg5 f5 27.exf6 Bc6 28.Nd1 e5 29.fxe5 Kf7 30.Rh7+
+- (2.66) Depth: 10/23 00:00:05 5kN
19.Qf6+ Bxf6 20.gxf6+ Kg8 21.Rxh7 Kxh7 22.Rh3+ Kg8 23.Bh6 Qc7 24.f4 Qe7 25.fxe7 Rfe8 26.Bg5 f5 27.exf6 Bc6 28.Nd1 e5 29.fxe5 Kf7 30.Rh7+
+- (2.87) Depth: 11/23 00:00:05 5kN
19.Qf6+ Bxf6 20.gxf6+ Kg8 21.Rxh7 Kxh7 22.Rh3+ Kg8 23.Bh6 Qc7 24.f4 Qe7 25.fxe7 Rfe8 26.Bg5 f5 27.exf6 Bc6 28.Nd1 e5 29.fxe5 Bd7 30.Rh6 Kf7
+- (2.98) Depth: 11/24 00:00:05 5kN
19.Qf6+ Bxf6 20.gxf6+ Kg8 21.Rxh7 Kxh7 22.Rh3+ Kg8 23.Bh6 Qc7 24.f4 Qa5 25.Bg7 Qa1+ 26.Kd2 Qd1+ 27.Nxd1 Rfc8 28.Rh8#
+- (3.62) Depth: 12/24 00:00:06 7kN

[Chessqueen]

Ok, I re-watched the video and did some analysis. The video author indicates it is a mate in 10, but of course that is ONLY IF back doesn't sacrifice its queen on the second move and makes the not so ideal response. Well, duh, mates are easy when the opponent blunders! By sac'ing the queen black guarantees a very long game even after having to give up a rook for a Knight or Bishop.

Actually, engines do see the move, if you set Multi PV to 2. But that second best move will never be played.

It is like the Plaskett's Puzzle described here.

https://en.wikipedia.org/wiki/Plaskett%27s_Puzzle

Sure, it is a shorter mate when black doesn't play optimally, but author's use that as an excuse to say, engines can't solve this. Well, they can, but the solution is a deeper mate that takes a heck of lot long.

Ok, off my soap box! LOL

Vin

I understand that engines can NOT solve this problem immediately, but any top 6 engines can win with White against any other engine playing Black and if so weather it is MATE in 10 or 16 with the Black Queen sacrificing itself on the 2nd move it is still a winnable position for White

Note: I let Crystal 4.0 play both sides, and you can chose any other top engine to play the Black Side and White will still win
[pgn][Event "are still unbeatable"]
[Site "DESKTOP-OFQ3C0P"]
[Date "2023.01.04"]
[Round "?"]
[White "Crystal.4.0.x64.avx2"]
[Black "Crystal.4.0.x64.avx2"]
[Result "*"]
[BlackElo "3600"]
[Time "13:14:17"]
[WhiteElo "3600"]
[TimeControl "360+10"]
[SetUp "1"]
[FEN "r2q1r2/1b2bpkp/n3p1p1/2ppP1P1/p6R/1PN1BQR1/NPP2P1P/4K3 w - - 0 35"]
[Termination "unterminated"]
[PlyCount "5"]
[WhiteType "program"]
[BlackType "program"]

35. Qf6+ {(Qf3-f6+ Be7xf6 g5xf6+ Qd8xf6 e5xf6+ Kg7xf6 Be3-g5+ Kf6-g7
Bg5-h6+ Kg7-g8 Bh6xf8 Kg8xf8 Rh4xh7 Kf8-e7 Nc3xa4 Bb7-c6 Rg3xg6 c5-c4
Rg6-g7 Bc6-e8 b3xc4 Na6-c7 Na2-c3 d5-d4 Rg7-g3 d4xc3 Na4xc3 Nc7-a6 Rg3-e3
Be8-c6 Rh7-h4 Na6-b4 Ke1-d2 Ra8-d8+ Kd2-c1 Bc6-e8 Nc3-d5+ Nb4xd5 c4xd5)
+7.25/28 18} Bxf6 {(Be7xf6 g5xf6+ Qd8xf6 e5xf6+ Kg7xf6 Be3-g5+ Kf6-g7
Bg5-h6+ Kg7-f6 Nc3xa4 Bb7-c6 Bh6xf8 Ra8xf8 Na4xc5 Na6xc5 Rg3-c3 g6-g5
Rh4-b4 Nc5-a6 Rc3xc6 Na6xb4 Na2xb4 Kf6-f5 Ke1-f1 Rf8-b8 Nb4-a6 Rb8-b5 b3-b4
h7-h5 b2-b3 Kf5-g4 Kf1-g2 Kg4-h4 Rc6-c5 Rb5-b7 b4-b5 g5-g4 Na6-b4 Rb7-b6
Nb4-d3 Rb6-b8 Rc5-c7 Rb8xb5 Rc7xf7 Kh4-g5 Rf7-f8 Rb5-b6 b3-b4 Rb6-c6 Nd3-c5
Kg5-h6 c2-c3 Kh6-g7) -7.26/32 83} 36. gxf6+ {(g5xf6+ Qd8xf6 e5xf6+ Kg7xf6
Be3-g5+ Kf6-g7 Bg5-h6+ Kg7-h8 Bh6xf8 Ra8xf8 Rh4xa4 d5-d4 Nc3-b5 Rf8-d8
b3-b4 c5xb4 Na2xb4 Na6-c5 Ra4-a7 e6-e5 Rg3-a3 e5-e4 Ra7xb7 Nc5xb7 Nb4-c6
Rd8-d5 Nc6xd4 Kh8-g8 Ra3-a8+ Kg8-g7 Ra8-a7 Nb7-d8 b2-b4 Kg7-f6 Ra7-a6+
Kf6-e7 c2-c4 Rd5-h5 c4-c5 Nd8-e6 c5-c6 Rh5xh2 Ra6-a7+ Ke7-f6 c6-c7)
+7.34/29 44} Kg8 37. Rxh7 {(Rh4xh7 Kg8xh7 Rg3-h3+ Kh7-g8 Be3-h6 Qd8-b8
f2-f4 Na6-b4 Bh6-g7 Qb8xe5+ f4xe5 Nb4xc2+ Ke1-f2 a4xb3 Rh3-h8+) +M8/23 24}
*[/pgn]

[Chessqueen]

Even a 2050 rated engine like Goldfish with White can beat Stockfish

[pgn][Event "Black position is lost"]
[Site "DESKTOP-OFQ3C0P"]
[Date "2023.01.04"]
[Round "?"]
[White "Goldfish.v1.13.0.64bit"]
[Black "Stockfish-windows-2022-x86-64-avx2"]
[Result "*"]
[BlackElo "3650"]
[Time "19:03:02"]
[WhiteElo "2050"]
[TimeControl "300+5"]
[SetUp "1"]
[FEN "r2q1r2/1b2bpkp/n3p1p1/2ppP1P1/p6R/1PN1BQR1/NPP2P1P/4K3 w - - 0 35"]
[Termination "normal"]
[PlyCount "56"]
[WhiteType "program"]
[BlackType "program"]


35. Qf6+ Bxf6 {(Be7xf6 g5xf6+) +5.55/13 12} 36. gxf6+ {(g5xf6+ Qd8xf6
e5xf6+ Kg7xf6 Be3-g5+ Kf6-g7 Bg5-h6+ Kg7-g8 Bh6xf8 Kg8xf8 Nc3xa4 Kf8-g7
b3-b4 c5-c4 Na4-b6 Ra8-b8 Rg3-a3 h7-h5 Rh4-d4 Na6-c7 Nb6-d7 Rb8-d8 Nd7-c5
Nc7-b5 Nc5xb7 Rd8-b8 Rd4-d1 Nb5xa3 b2xa3 Rb8xb7 a3-a4 Kg7-f6 b4-b5 Kf6-e7
Rd1-b1 Ke7-d6) +4.63/33 59} Kg8 {(Kg7-g8 Rg3-h3 h7-h5 Nc3xa4 Qd8-b8 Na4-b6
Qb8xe5 Nb6xa8 Rf8xa8 c2-c3 Qe5xf6 Be3-f4) +5.62/13 15} 37. Rxh7 {(Rh4xh7
Kg8xh7 Rg3-h3+ Kh7-g8 Be3-h6 Qd8-c7 f2-f4 Na6-b4 Bh6-g7 Qc7xe5+ f4xe5
Nb4xc2+ Ke1-d2 a4xb3 Rh3-h8+) +M8/84 15} Kxh7 {(Kg8xh7 Rg3-h3+ Kh7-g8
Be3-h6 Qd8-b8 Bh6-g7 Qb8xe5+ Ke1-f1 Qe5-h5 Rh3xh5 g6xh5 Bg7xf8 Ra8xf8
b3xa4) +4.09/11 15} 38. Rh3+ {(Rg3-h3+ Kh7-g8 Be3-h6 Qd8-c7 f2-f4 Na6-b4
Bh6-g7 Qc7xe5+ f4xe5 Nb4xc2+ Ke1-d2 a4xb3 Rh3-h8+) +M7/102 16} Kg8
{(Kh7-g8) +4.11/1 15} 39. Bh6 {(Be3-h6 Qd8-c7 f2-f4 Na6-b4 Bh6-g7 Qc7xe5+
f4xe5 Nb4xc2+ Ke1-d2 a4xb3 Rh3-h8+) +M6/145 16} Qb8 {(Qd8-b8 f2-f4 Qb8xe5+
f4xe5 Na6-b4 Bh6-g7 Nb4-d3+ c2xd3 Rf8-d8 Rh3-h8+) -M5/12 2} 40. f4 {(f2-f4
Na6-b4 Bh6-g7 Qb8xe5+ f4xe5 Nb4xc2+ Ke1-d2 a4xb3 Rh3-h8+) +M5/241 14} Qxe5+
{(Qb8xe5+) -M4/8 0} 41. fxe5 {(f4xe5 Na6-b4 Bh6-g7 Nb4xc2+ Ke1-d2 a4xb3
Rh3-h8+) +M4/245 0} Nb4 {(Na6-b4) -M3/6 0} 42. Bg7 {(Bh6-g7 Nb4xc2+ Ke1-d2
a4xb3 Rh3-h8+) +M3/245 0} Nxc2+ {(Nb4xc2+) -M2/5 0} 43. Kd2 {(Ke1-d2 a4xb3
Rh3-h8+) +M2/245 0} axb3 {(a4xb3 Rh3-h8+) -M1/2 Black resigns} *[/pgn]