c is the most often played move in my pro database (in this local position). (13x) (Congrats Blindgroup )
d is played 8x
e is played 8x
f is played 4x
b is played 3x
my "blunder" a is played 0x
Zen 7 is suggesting that a,b,c and d have about the same value (whole board) (Zen also likes Q18).
I think c is most often played because it takes profit at once, it has good follow up moves and it avoids further complications down the line. Similar b and d strengthen the black position in the upper left. Move a is not a bad move but a bit loose compared to the other moves, probably there are more ways for white to mess around later. (For example in the game:
[go]$$B
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$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O O . O . . . . . . . . . . . . |
$$ | . . . O O O X X . , . . . . . X . . . |
$$ | . . X X O X . . X . . . . . . . . . . |
$$ | . . . . X X . O X . . . . . . . . . . |
$$ | . . . . . . . W O . . . . . . . . . . |
$$ | . . . O . a . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . b . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . X . . X X . . |
$$ | . O O , O X . . . , . O O X X , O . . |
$$ | . O X X X . . . X . O . X O X . X . . |
$$ | . . . . . . . . . . . . . O O O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Just intuitively without checkin any reading or counting (so using my "blitz" eyes so to speak) I'd play a or b - probably A with the idea that I'll settle my weak group while harrassing white's only potential on the board then I'll get to go back and build while attacking his three stones
a is my ten-seconds-of-thinking move as well, isolating White's three stones in the middle and potentially helping out an invasion on the left side. I think it might even protect against the cut at D14, though when I initially looked I was content to give those two stones away if they got cut.
Edit: no, it doesn't protect the cut. I'm still fine with giving away those two stones for a new string of stones on the 13th line.
[go]$$B
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . X . . . . . . . X . . O . . |
$$ | . c . X . . . . . d . . . . . X . O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O b . e . . . . . . . . . X O O . |
$$ | . . . . a . . . . . . . . . . X X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , f . . |
$$ | . . . . . . . . . . . . . . . h . . . |
$$ | . . O . . . . . . . . . . g . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X O . . . . . . . . . O . . . . . |
$$ | . O O . . . . . . . . . . . . O O . . |
$$ | . X O O . O . . X , . . . . X X O . . |
$$ | . X X . . . . . X O . . . X . . X X . |
$$ | . . . . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Two observations: the top is the big area and White is already slightly overconcentrated at the left side. Therefore the moves to consider are 'd', simply staking out the top, and 'b' gaining extra influence while overconcentrating White even more. This gives rise to the question whether 'b' is sente. Move 'c' and Bill's 'e' are too single minded for my taste. Neither affects the left side in a major way and so White has hands free to move into the big top side. In that respect 'c' is better than 'e' because it takes territory. Finally, Ed's 'f' attacks the white group from an uninteresting side. It's better to wait until the action at the top reveals whether a move around 'g' or 'h' would become double purpose.
Answering the question, I find White has more flexibility to switch his attention from the left side to the top and corner. Black's 'a' next does not look all that devastating, while White's 'b' grabs the corner. It seems to me that Black is making things too complicated.
I like the simplicity of 'd' in the original diagram, 1 here, better. I'm not entirely happy with the remainder of the development, but still feel that White is overconcentrated.
Problem 6:
I blundered and instantly knew my reaction to this black play was wrong. What is your intuiton for white's next move?
$$W
$$ ---------------------------------------
$$ | . . . . . . X . . . . . . X . . . . . |
$$ | . . . . . X . X O . . X X O X X . . . |
$$ | . . O . X X X O . . O O O O O . X . . |
$$ | . . O X . X O O . , . . . . . O . X . |
$$ | . . . . . X . O . . . . . . . O O O X |
$$ | . . O . . . X X X . . . . O X O X X . |
$$ | . . . O . X O X . . . . . O O X . . . |
$$ | . . X O . O O . O . . . . . X X . . . |
$$ | . . . X O . . . . X O . . . . X . . . |
$$ | . . . X . . . X . X O . . . O O X X . |
$$ | . . X . . O . . . O . . . . . . O X . |
$$ | . . . . O . . X . . . . . . . O . O . |
$$ | . . . . O X O X O . . . . . O O O . . |
$$ | . X X X . X X . O . . . . . O X O O . |
$$ | . . O X X O X X O . . . O O . X X X X |
$$ | . . O , . O O X . , B . O X X X . O . |
$$ | . . . O . O . . X . . O X . X . X O . |
$$ | . . . . . . . . . . . . O X . . X X O |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
[go]$$W
$$ ---------------------------------------
$$ | . . . . . . X . . . . . . X . . . . . |
$$ | . . . . . X . X O . . X X O X X . . . |
$$ | . . O . X X X O . . O O O O O . X . . |
$$ | . . O X . X O O . , . . . . . O . X . |
$$ | . . . . . X . O . . . . . . . O O O X |
$$ | . . O . . . X X X . . . . O X O X X . |
$$ | . . . O . X O X . . . . . O O X . . . |
$$ | . . X O . O O . O . . . . . X X . . . |
$$ | . . . X O . . . . X O . . . . X . . . |
$$ | . . . X . . . X . X O . . . O O X X . |
$$ | . . X . . O . . . O . . . . . . O X . |
$$ | . . . . O . . X . . . . . . . O . O . |
$$ | . . . . O X O X O . . . . . O O O . . |
$$ | . X X X . X X . O . . . . . O X O O . |
$$ | . . O X X O X X O . . . O O . X X X X |
$$ | . . O , . O O X . , B . O X X X . O . |
$$ | . . . O . O . . X . . O X . X . X O . |
$$ | . . . . . . . . . . . . O X . . X X O |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Solution:
All good answers are non local plays
$$W
$$ ---------------------------------------
$$ | . . . . . . X . . . . . . X . . . . . |
$$ | . . . d . X . X O . . X X O X X . . . |
$$ | . . O . X X X O . . O O O O O . X . . |
$$ | . . O X . X O O . , . . . . . O . X . |
$$ | . . . . . X . O . . . . . . . O O O X |
$$ | . . O . . . X X X . . . . O X O X X . |
$$ | . . . O . X O X . . . . . O O X . . . |
$$ | . b X O . O O . O . . . . . X X . . . |
$$ | . . . X O . . . . X O . . . . X . . . |
$$ | . . . X . . . X . X O . . . O O X X . |
$$ | . . X . . O . . . O . . . . . . O X . |
$$ | . . c . O . . X . . . . . . . O . O . |
$$ | . . . . O X O X O . . . . . O O O . . |
$$ | . X X X . X X . O . . . . . O X O O . |
$$ | . . O X X O X X O . . . O O . X X X X |
$$ | . . O , . O O X . , B . O X X X . O . |
$$ | . . . O . O . . X . . O X . X . X O . |
$$ | . . . . . . . a . . . . O X . . X X O |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
[go]$$W
$$ ---------------------------------------
$$ | . . . . . . X . . . . . . X . . . . . |
$$ | . . . d . X . X O . . X X O X X . . . |
$$ | . . O . X X X O . . O O O O O . X . . |
$$ | . . O X . X O O . , . . . . . O . X . |
$$ | . . . . . X . O . . . . . . . O O O X |
$$ | . . O . . . X X X . . . . O X O X X . |
$$ | . . . O . X O X . . . . . O O X . . . |
$$ | . b X O . O O . O . . . . . X X . . . |
$$ | . . . X O . . . . X O . . . . X . . . |
$$ | . . . X . . . X . X O . . . O O X X . |
$$ | . . X . . O . . . O . . . . . . O X . |
$$ | . . c . O . . X . . . . . . . O . O . |
$$ | . . . . O X O X O . . . . . O O O . . |
$$ | . X X X . X X . O . . . . . O X O O . |
$$ | . . O X X O X X O . . . O O . X X X X |
$$ | . . O , . O O X . , B . O X X X . O . |
$$ | . . . O . O . . X . . O X . X . X O . |
$$ | . . . . . . . a . . . . O X . . X X O |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Last edited by Gomoto on Tue Jan 16, 2018 11:19 am, edited 1 time in total.
$$W
$$ ---------------------------------------
$$ | . . . . . . X . . . . . . X . . . . . |
$$ | . . . . . X . X O . . X X O X X . . . |
$$ | . . O . X X X O . . O O O O O . X . . |
$$ | . . O X . X O O . , . . . . . O . X . |
$$ | . . . . . X . O . . . . . . . O O O X |
$$ | . . O . . . X X X . . . . O X O X X . |
$$ | . . . O . X O X . . . . . O O X . . . |
$$ | . . X O . O O . O . . . . . X X . . . |
$$ | . . . X O . . . . X O . . . . X . . . |
$$ | . . . X . . . X . X O . . . O O X X . |
$$ | . . X . . O . . . O . . . . . . O X . |
$$ | . . . . O . . X . . . . . . . O . O . |
$$ | . . . . O X O X O . . . . . O O O . . |
$$ | . X X X . X X . O . . . . . O X O O . |
$$ | . . O X X O X X O . . . O O . X X X X |
$$ | . . O , . O O X . 1 X . O X X X . O . |
$$ | . . . O . O . . X . . O X . X . X O . |
$$ | . . . . . . . . . . . . O X . . X X O |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
[go]$$W
$$ ---------------------------------------
$$ | . . . . . . X . . . . . . X . . . . . |
$$ | . . . . . X . X O . . X X O X X . . . |
$$ | . . O . X X X O . . O O O O O . X . . |
$$ | . . O X . X O O . , . . . . . O . X . |
$$ | . . . . . X . O . . . . . . . O O O X |
$$ | . . O . . . X X X . . . . O X O X X . |
$$ | . . . O . X O X . . . . . O O X . . . |
$$ | . . X O . O O . O . . . . . X X . . . |
$$ | . . . X O . . . . X O . . . . X . . . |
$$ | . . . X . . . X . X O . . . O O X X . |
$$ | . . X . . O . . . O . . . . . . O X . |
$$ | . . . . O . . X . . . . . . . O . O . |
$$ | . . . . O X O X O . . . . . O O O . . |
$$ | . X X X . X X . O . . . . . O X O O . |
$$ | . . O X X O X X O . . . O O . X X X X |
$$ | . . O , . O O X . 1 X . O X X X . O . |
$$ | . . . O . O . . X . . O X . X . X O . |
$$ | . . . . . . . . . . . . O X . . X X O |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Since you ask for intuition and not for reading the first move I look at is cutting across the knight's move:
$$W
$$ ---------------------------------------
$$ | . . . . . . X . . . . . . X . . . . . |
$$ | . . . . . X . X O . . X X O X X . . . |
$$ | . . O . X X X O . . O O O O O . X . . |
$$ | . . O X . X O O . , . . . . . O . X . |
$$ | . . . . . X . O . . . . . . . O O O X |
$$ | . . O . . . X X X . . . . O X O X X . |
$$ | . . . O . X O X . . . . . O O X . . . |
$$ | . . X O . O O . O . . . . . X X . . . |
$$ | . . . X O . . . . X O . . . . X . . . |
$$ | . . . X . . . X . X O . . . O O X X . |
$$ | . . X . . O . . . O . . . . . . O X . |
$$ | . . . . O . . X . . . . . . . O . O . |
$$ | . . . . O X O X O . . . . . O O O . . |
$$ | . X X X . X X . O . . . . . O X O O . |
$$ | . . O X X O X X O . . . O O . X X X X |
$$ | . . O , . O O X . , B . O X X X . O . |
$$ | . . . O . O . . X 1 . O X . X . X O . |
$$ | . . . . . . . . . . . . O X . . X X O |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
[go]$$W
$$ ---------------------------------------
$$ | . . . . . . X . . . . . . X . . . . . |
$$ | . . . . . X . X O . . X X O X X . . . |
$$ | . . O . X X X O . . O O O O O . X . . |
$$ | . . O X . X O O . , . . . . . O . X . |
$$ | . . . . . X . O . . . . . . . O O O X |
$$ | . . O . . . X X X . . . . O X O X X . |
$$ | . . . O . X O X . . . . . O O X . . . |
$$ | . . X O . O O . O . . . . . X X . . . |
$$ | . . . X O . . . . X O . . . . X . . . |
$$ | . . . X . . . X . X O . . . O O X X . |
$$ | . . X . . O . . . O . . . . . . O X . |
$$ | . . . . O . . X . . . . . . . O . O . |
$$ | . . . . O X O X O . . . . . O O O . . |
$$ | . X X X . X X . O . . . . . O X O O . |
$$ | . . O X X O X X O . . . O O . X X X X |
$$ | . . O , . O O X . , B . O X X X . O . |
$$ | . . . O . O . . X 1 . O X . X . X O . |
$$ | . . . . . . . . . . . . O X . . X X O |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
My concern with move "e" is that even assuming white answers patiently at x or y, black does not seem to gain from the exchange, since the potential territory on the right is very small and open, while white moving into the center weakens black's potential on the upper side.