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Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Wed Oct 10, 2018 10:34 am
by Gomoto
Let us have a look at this game. I would like know your fellow human opinions on some of the moves.

Lee Jihyun (m), 9p - Lee Changho, 9p, B+R (Komi 6.5)
year 2018 Korean League, round 14, 2018-10-06



Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Wed Oct 10, 2018 10:36 am
by Gomoto
Move 13 is the first play I am curious about.
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . O . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . a . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . B O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . O . . . . . . . X . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
This move is popular with the pros, but the play at a has a much higher winrate (72% in 30 games > 48% in 152 games) on Waltheri's http://ps.waltheri.net/248432/. Nontheless the play at B12 is also still popular in recent pro games. Elf shows a 14% drop for this move. What do you think about the both options B12 and E14?

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Wed Oct 10, 2018 10:55 am
by Gomoto
Move 46 is the next move that puzzles me. This is not the way white should play in this shape in my opinion. Elf shows a 10% loss and recommends a play at a or b.
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . O . . . . . . . O X . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . X . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . O . X . . . . |
$$ | . X O . . . . . . . . . . W . . . . . |
$$ | . . . . . . . . . . . a O X . . . . . |
$$ | . . X , . . . . . , . b X . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X X . |
$$ | . . . . . . . . . X X . . . . O O X . |
$$ | . . . . . . . . . O X . X X . X X O . |
$$ | . . . O . . . . . O O . O . . X O O . |
$$ | . . . . . O . . . . . . . X X O . O . |
$$ | . . . . . . . . . . . . . . . O . X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
I want to sharpen my opinion on this shape and want to show you what I think right now (which may be flawed):

I (and my pro database) consider these moves from a to f to be good candidate moves for white in relation to the black keima shape:
Click Here To Show Diagram Code
[go]$$W
$$ . . . . . . .
$$ . . . . . . .
$$ . b a X . . .
$$ . d . . f . .
$$ . . O . X . .
$$ . . . . c . .
$$ . . . . . . .[/go]

This is not a valid candidate move! (Not to mention I managed to blunder this one today in one of my games, allthough I should know the keima and its properties already.)
Click Here To Show Diagram Code
[go]$$B
$$ . . . . . . .
$$ . . . . . . .
$$ . . . X . . .
$$ . . . P . . .
$$ . . O . X . .
$$ . . . . . . .
$$ . . . . . . .[/go]

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Wed Oct 10, 2018 11:37 am
by paK0
No 3-3 invasions and playing gote moves to make shape, what is this, 2015? :lol:

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Wed Oct 10, 2018 11:50 am
by Gomoto
This is Lee Changho :tmbup:

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Wed Oct 10, 2018 12:01 pm
by Gomoto
Some more pro games with the discussed the shape.

(I am aware that this not a pure shape issue but depending on the board position and tactics, but nevertheless in these games the discussed move is questionable too and the play at a probably superior.)

Cho Hanseung, 9p - Park Yeonghun, 9p, W+0.5 (Komi 6.5)
19th Korean Maxim Cup, final 3, 2018-04-23:

Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X X X . . . . X . . . . . . . . . |
$$ | . . O X O X X X . . . . . . . O O . . |
$$ | . . . O O O O O O , . X . O . X . . . |
$$ | . . O . . . . . . . . . . . . . X . . |
$$ | . . O X . . . . . . . . . O . X O . . |
$$ | . O X . . . . . . . . . . . . . X . . |
$$ | . O X . . X . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . X . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . O . O O . . . . . . . . . . . . |
$$ | . . . . . . X . a . . . . . . . . . . |
$$ | . . . . . . . . O X . X . . . . . . . |
$$ | . . X O . O X . . O Z . . X . , X . . |
$$ | . . O . . O . . . . . O . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Yamada Kimio, 9p - So Kofuku, 9p, W+R (Komi 6.5)
25th Japanese Ryusei, group C, 2016-02-04:

Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . O X O O . . |
$$ | . . . . O . . . . O . . . O X X O . . |
$$ | . . . O . . . . . , Z O . . . X O . . |
$$ | . . . . . . . . . X . X O . X . O O . |
$$ | . . O . . . X X . . . a . . . X X X . |
$$ | . . O X O O O X O . . . . . . . . . . |
$$ | . . O . . . O X O X . . . . . . . . . |
$$ | . . X X X . X O O . . . . . . . . . . |
$$ | . . X O . X X X O , . . . . . , . . . |
$$ | . O O . . X O O . . . . . X . . X . . |
$$ | . . . O . X X O . . . . . . . . . . . |
$$ | . . . O O . . O X . . . . . . . . . . |
$$ | . . O X . X X . O O O O O X . . . . . |
$$ | . . O X X X O X O X X X X X X X . . . |
$$ | . . O O O X . . O X O O O X X , . . . |
$$ | . O O X O X . . O O X X . O . X . . . |
$$ | O X X X X X O . . . O . X . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Xiao Zhenghao, 9p - Chen Shiyuan, 9p, W+2.5 (Komi 6.5)
11th Taiwan Guoshou, title match #3, 2015-12-01:

Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X X . X . . . . . . . O . X . . . |
$$ | . X O O O . . . . , . . . . . X . . . |
$$ | . O O . . . . . . . . . . . . X X . . |
$$ | . . X . . . . . . . . . . O O X O . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . O O O . . . . . . . . . O . O . . |
$$ | . . O X . X . . . . . . . . . X X . . |
$$ | . . . X . . . . . , . . . X . , . . . |
$$ | . . . . . . X . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . . . . . . O . . . . . . . X . . |
$$ | . . . O . . O Z . , O . . . . , . . . |
$$ | . . . . . O X . X . . . . O . X . . . |
$$ | . . . . . a . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Cho Hunhyun, 9p - Cho Chikun, 9p, W+T (Komi 6.5)
Memorial - 70th anniversary of modern Korean Go, 2015-07-26:


(tongue in cheek example)
Click Here To Show Diagram Code
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . X . . . . . . . . . . . |
$$ | . . X O . X . . . X X . O . X . . . . |
$$ | . . . O . X O . O , O O . . . X . . . |
$$ | . O O . . . . . . . . . . . . . . O . |
$$ | . . X X . . . . . . . . . . X X O . . |
$$ | . . . . X X X . . . O . . . . O X . . |
$$ | . . . O O O X . O Z . . . . . O X . . |
$$ | . . . . . . a O X . X . . . X X X O . |
$$ | . . . , . . . . . , . . . . O O O . O |
$$ | . . . . . . . . . . . . . . . X X O . |
$$ | . . . . . . . . . . . O . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . O . . . X X O . . . . . . . |
$$ | . . O X . . O X X O . O . . . . . . . |
$$ | . . O O X X O X O O . O . X . X . . . |
$$ | . . O X . X O O . . X . X . . . . . . |
$$ | . O X . X . . . O X . . . . . . . . . |
$$ | . X . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Thu Oct 11, 2018 5:27 pm
by ez4u
But notice that none of your examples fit the 'pure' shape that you showed above. All have extra stones close by. The general theory may support arm-chair critiques, but is not necessarily relevant when the pros get down and dirty.
:)

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Thu Oct 11, 2018 5:42 pm
by Gomoto
I just keep the eyes open for this shape in my own games. In all the shown pro games the alternative move is considered better by elf.

I am still prone to make this move in a pure keima situation where it is clearly bad in my own games. In the discussed shape (were the move sometimes makes sense) it is at least worthwhile not to play this move too fast and check the alternatives thoroughly first. This is my personal consequence from percieving the significant elf winrate loss in the Lee Changho game.

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Thu Oct 11, 2018 10:14 pm
by Calvin Clark
Gomoto wrote:What do you think about the both options B12 and E14?
Both are joseki and it's early enough in the game that I wouldn't think either is really bad off the top of my head. I am nowhere near strong enough to judge this. Maybe ELF is lazy about reading ladders and just avoids variations that depend on it more?

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Fri Oct 12, 2018 9:02 am
by Elom
Is 10% that big for Elf, though? :)

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Fri Oct 12, 2018 9:29 am
by Gomoto
Let us have a look at some pro games and try to explore elfs reasoning.
strange1.jpg
strange1.jpg (177.56 KiB) Viewed 14427 times
strange2.jpg
strange2.jpg (176.14 KiB) Viewed 14427 times

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Fri Oct 12, 2018 9:33 am
by Elom
At move 46, if white plays at b and black plays an atari at N12, what should white do? Play at M12?

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Fri Oct 12, 2018 9:39 am
by Gomoto
... elf's continuations:

strange3.jpg
strange3.jpg (179.01 KiB) Viewed 14424 times
strange4.jpg
strange4.jpg (177.6 KiB) Viewed 14424 times

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Fri Oct 12, 2018 9:41 am
by Gomoto
And in the Lee Changho game:
strange5.jpg
strange5.jpg (161.75 KiB) Viewed 14424 times
strange6.jpg
strange6.jpg (164.78 KiB) Viewed 14422 times

Re: Lee Jihyun vs. Lee Changho 2018-10-06 Strange Moves?

Posted: Fri Oct 12, 2018 9:47 am
by Gomoto
elf's continuations
strange8.jpg
strange8.jpg (166.76 KiB) Viewed 14421 times
strange7.jpg
strange7.jpg (163.27 KiB) Viewed 14421 times