An easy position, for humans

[Rodolfo Leoni]

W King is tied to black f4 pawn. B King will always move Kd7-d8-d7-d8.... A clear and easy draw. But engines cannot see it.

[d]8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 1 71

[Vinvin]

Strange ! Engines should see quickly a draw by repetition : no side can make progress !
Thanks for this position !

[Rodolfo Leoni]

Strange ! Engines should see quickly a draw by repetition : no side can make progress !
Thanks for this position !

Hi Vincent,

W king has all squares inside f4-f1-c1-c4 to go for avoiding a three fold by repetition. Since evaluation table returns a positive value (one pawn advantage + 2 passers) engine only searches to avoid the repetition. As a result, we get a recursive score.

I wonder if there's a way to detect it for having better evaluations...

[Ignacio]

W King is tied to black f4 pawn. B King will always move Kd7-d8-d7-d8.... A clear and easy draw. But engines cannot see it.

[d]8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 1 71

If B king moves Kd8 is 1-0. Correct is Kd7-d6-d7-d6.

[MikeGL]

W King is tied to black f4 pawn. B King will always move Kd7-d8-d7-d8.... A clear and easy draw. But engines cannot see it.

[d]8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 1 71

Thanks for this position.
Black king is just in time to save black position.

Not clear cut draw IMHO, maybe engines are clever not to give 0.00 because there are chances for mistakes in case black is a human or the opposing engine is weak and doesn't know how to proceed. Some moves on this possible continuation still requires precision.

[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.21"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "?"]
[BlackElo "2400"]
[SetUp "1"]
[FEN "8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 1 71"]
[Termination "unterminated"]
[PlyCount "35"]
[WhiteType "human"]
[BlackType "human"]

71. Kd4 Kd7 72. Ke5 f3 73. b7 (73. d6 f2 74. b7 f1=Q 75. b8=Q Qf4+ 76.
Kd5=) 73. .. Kc7 74. d6+ Kxb7 75. Ke6 f2 76. d7 f1=Q 77. d8=Q Qf2 78. Qd5+
Kb6 79. Qf5 Qf4 80. Kf6 Kc6 81. Kg7 Kd6 82. Kxh6 Qxf5 83. gxf5 g4 84. f6
Ke6 85. Kg7 g3 86. f7 g2 87. f8=Q g1=Q+ 88. Kh7=
[/pgn]

This is my shallow analysis using a 32bit engine. Maybe there are also some tricks hidden, especially zugzwangs which escaped the engine during my quick analysis.

regards

[Rodolfo Leoni]

W King is tied to black f4 pawn. B King will always move Kd7-d8-d7-d8.... A clear and easy draw. But engines cannot see it.

[d]8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 1 71

If B king moves Kd8 is 1-0. Correct is Kd7-d6-d7-d6.

Oooops. A type error.
Of course, I meant Kd6-d7-d6-d7......

[Uri Blass]

W King is tied to black f4 pawn. B King will always move Kd7-d8-d7-d8.... A clear and easy draw. But engines cannot see it.

[d]8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 1 71

If black king always move Kd7-d8 then b7 wins.

practically 1.b7 Kc7 2.Kf5 and it is a draw but I do not think that it is simple for humans to be sure about it.

[Rodolfo Leoni]

W King is tied to black f4 pawn. B King will always move Kd7-d8-d7-d8.... A clear and easy draw. But engines cannot see it.

[d]8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 1 71

If black king always move Kd7-d8 then b7 wins.

practically 1.b7 Kc7 2.Kf5 and it is a draw but I do not think that it is simple for humans to be sure about it.

A type error, Uri...
Kd7-d6-d7-d6...

[Rodolfo Leoni]

W King is tied to black f4 pawn. B King will always move Kd7-d8-d7-d8.... A clear and easy draw. But engines cannot see it.

[d]8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 1 71

Thanks for this position.
Black king is just in time to save black position.

Not clear cut draw IMHO, maybe engines are clever not to give 0.00 because there are chances for mistakes in case black is a human or the opposing engine is weak and doesn't know how to proceed. Some moves on this possible continuation still requires precision.

[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.21"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "?"]
[BlackElo "2400"]
[SetUp "1"]
[FEN "8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 1 71"]
[Termination "unterminated"]
[PlyCount "35"]
[WhiteType "human"]
[BlackType "human"]

71. Kd4 Kd7 72. Ke5 f3 73. b7 (73. d6 f2 74. b7 f1=Q 75. b8=Q Qf4+ 76.
Kd5=) 73. .. Kc7 74. d6+ Kxb7 75. Ke6 f2 76. d7 f1=Q 77. d8=Q Qf2 78. Qd5+
Kb6 79. Qf5 Qf4 80. Kf6 Kc6 81. Kg7 Kd6 82. Kxh6 Qxf5 83. gxf5 g4 84. f6
Ke6 85. Kg7 g3 86. f7 g2 87. f8=Q g1=Q+ 88. Kh7=
[/pgn]

This is my shallow analysis using a 32bit engine. Maybe there are also some tricks hidden, especially zugzwangs which escaped the engine during my quick analysis.

regards

I guess 77. .. Qe2+ would have been a bit more incisive, but draw anyway.

[MikeGL]

W King is tied to black f4 pawn. B King will always move Kd7-d8-d7-d8.... A clear and easy draw. But engines cannot see it.

[d]8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 1 71

Thanks for this position.
Black king is just in time to save black position.

Not clear cut draw IMHO, maybe engines are clever not to give 0.00 because there are chances for mistakes in case black is a human or the opposing engine is weak and doesn't know how to proceed. Some moves on this possible continuation still requires precision.

[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.21"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "?"]
[BlackElo "2400"]
[SetUp "1"]
[FEN "8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 1 71"]
[Termination "unterminated"]
[PlyCount "35"]
[WhiteType "human"]
[BlackType "human"]

71. Kd4 Kd7 72. Ke5 f3 73. b7 (73. d6 f2 74. b7 f1=Q 75. b8=Q Qf4+ 76.
Kd5=) 73. .. Kc7 74. d6+ Kxb7 75. Ke6 f2 76. d7 f1=Q 77. d8=Q Qf2 78. Qd5+
Kb6 79. Qf5 Qf4 80. Kf6 Kc6 81. Kg7 Kd6 82. Kxh6 Qxf5 83. gxf5 g4 84. f6
Ke6 85. Kg7 g3 86. f7 g2 87. f8=Q g1=Q+ 88. Kh7=
[/pgn]

This is my shallow analysis using a 32bit engine. Maybe there are also some tricks hidden, especially zugzwangs which escaped the engine during my quick analysis.

regards

I guess 77. .. Qe2+ would have been a bit more incisive, but draw anyway.

Without a syzygy or nalimov tablebase on our brain, that would be playing
with fire and very dangerous to play OTB in a tournament. Helping blacks
King to reach h6 with free tempo might make me sweat in a real game.

[pgn]
[Event "Computer chess game"]
[Site "Talkchess"]
[Date "2017.07.21"]
[Round "?"]
[White "?"]
[Black "?"]
[Result "*"]
[TimeControl "360+6"]
[SetUp "1"]
[FEN "8/8/1P1k3p/3P2pP/4KpP1/8/8/8 w - - 0 71"]
[Termination "unterminated"]
[PlyCount "35"]
[WhiteType "human"]
[BlackType "human"]

71. Kd4 Kd7 72. Ke5 f3 73. b7 (73. d6 f2 74. b7 f1=Q 75. b8=Q Qf4+ 76. Kd5)
73. .. Kc7 74. d6+ Kxb7 75. Ke6 f2 76. d7 f1=Q 77. d8=Q Qf2 (77. .. Qe2+
78. Kf5 Qf3+ 79. Kg6 Qxg4 80. Qd5+ Kb6 81. Kxh6 Qf4 82. Qxg5 Qf8+ 83. Qg7
Qf4+ 84. Kh7 Ka5) 78. Qd5+ Kb6 79. Qf5 Qf4 80. Kf6 Kc6 81. Kg7 Kd6 82. Kxh6
Qxf5 83. gxf5 g4 84. f6 Ke6 85. Kg7 g3 86. f7 g2 87. f8=Q g1=Q+ 88. Kh7 =
[/pgn]

Inserted your Qe2+ line, but final position looks scary. But you are correct, still a draw.


regards