John Fairbairn wrote:
One unattributed review said that White J17 was more usual for 14. Black made a lot of profit with 19. White 20 and 22 embarked on a big moyo strategy. Black 27 and 29 were a probe.
The comments by the reviewer are reasonable enough. To me the first part is like the narration over some documentary movie.
I guess the "more usual" move is the extension, the orientation of the coordinates is different.
John Fairbairn wrote:
If Black answers White 34 at H4, White jumps to 35. The cap at Black 34 was kiai.
- Click Here To Show Diagram Code
[go]$$B
$$ +--------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . X . . . . . . . . . . . . . . .|
$$ | . . . X O . . . . X . . . . . . . . .|
$$ | . . X O . . . . . , . 1 . X . X . . .|
$$ | . . X O . O . . . O . . . . . . . . .|
$$ | . . X . . . . . . . . . . . . . O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . , . . . . . , . . . . . O . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . O . . . . . . . . . . . . .|
$$ | . . X . . . . . . X . . . . . . . . .|
$$ | . . . . . X . . . . . . 2 . . . O . .|
$$ | . . X , O O O . . X . . . . . O . . .|
$$ | . . . X X O . . . . . . O . X O . . .|
$$ | . . . . . . . . . . . . . . . X O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]
I think this means that white can play a good enough move on the bottom if black simply defends on the top and it is not the exact move that is important. It is a reasonable explanation, defending looks to me like something for a handicap game. Maybe 'kiai' was the normal level of active play for the time?
John Fairbairn wrote:
For the sagari of White 44, cutting at 48 is better timing; then if Black 51 there is bad aji.
Now I get a feeling that I have seen the comments before, maybe repackaged. It is also interesting because KataGo doesn't like the good timing move. It does set things in motion, it is the right time for that, but KataGo sort of refutes the move.
- Click Here To Show Diagram Code
[go]$$W KataGo wants to handle it like this.
$$ +--------------------------------------+
$$ | . . . . . . . . . . 7 . . . . . . . .|
$$ | . . . X . . . . 2 8 X 1 . . . 3 . . .|
$$ | . . . X O . . . . X O X 9 . X O X . .|
$$ | . . X O . . . . . , O 0 . X . X O 5 .|
$$ | . . X O . O . . . O . . . . . 6 4 . .|
$$ | . . X . . . . . . . . . . . . . O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . , . . . . . , . . . . . O . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . O . . . . . . . . . . . . .|
$$ | . . X . . . . . . X . . . . . . . . .|
$$ | . . . . . X . . . . . . X . . . O . .|
$$ | . . X , O O O . . X . . . . . O . . .|
$$ | . . . X X O . . . . . . O . X O . . .|
$$ | . . . . . . . . . . . . . . . X O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]
- Click Here To Show Diagram Code
[go]$$Wm11
$$ +--------------------------------------+
$$ | . . . . . . . . . . O 8 . . . . . . .|
$$ | . . . X . . . . X X X O 4 7 9 O . . .|
$$ | . . . X O . . . . X O X O . X O X . .|
$$ | . . X O . . . . . , O X 1 X . X O O .|
$$ | . . X O . O . . . O . 2 3 . . X X 5 .|
$$ | . . X . . . . . . . . 6 . . . . O . .|
$$ | . . . . 0 . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . , . . . . . , . . . . . O . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . O . . . . . . . . . . . . .|
$$ | . . X . . . . . . X . . . . . . . . .|
$$ | . . . . . X . . . . . . X . . . O . .|
$$ | . . X , O O O . . X . . . . . O . . .|
$$ | . . . X X O . . . . . . O . X O . . .|
$$ | . . . . . . . . . . . . . . . X O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]
Even though
let's white's stones settle black nevertheless appears to take good advantage of white's thinness. Black KataGo will also take control of the flow of the game for a good while in a position that was already advantageous.
I guess there is no telling if a human opponent like Otake would play this way and practically, when not playing a computer, someone might just prefer the early cash for white.
I wasn't going to rate every observation by the unattributed reviewer but I think it reasonable to call this a good timing, despite KataGo's -1.5 points reaction (the whole sequence starting on move 40 is -3.2 points). I'm not sure what the reviewer means by "bad aji" as black's next move would be very big and white therefore needs to play first in this area anyway.
If black had played the other atari in the corner then the good timing move is approved. In this case white's outside is improved.
- Click Here To Show Diagram Code
[go]$$W
$$ +--------------------------------------+
$$ | . . . . . . . . . . 3 . . . . . . . .|
$$ | . . . X . . . . 2 4 X 1 . . 8 5 6 . .|
$$ | . . . X O . . . . X O X 7 . X O X . .|
$$ | . . X O . . . . . , O . . X . X O X .|
$$ | . . X O . O . . . O . . . . . . O . .|
$$ | . . X . . . . . . . . 9 . . . . O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . , . . . . . , . . . . . O . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . O . . . . . . . . . . . . .|
$$ | . . X . . . . . . X . . . . . . . . .|
$$ | . . . . . X . . . . . . X . . . O . .|
$$ | . . X , O O O . . X . . . . . O . . .|
$$ | . . . X X O . . . . . . O . X O . . .|
$$ | . . . . . . . . . . . . . . . X O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]
John Fairbairn wrote:
After 49, Black's has a lot of territory. If White 50 at K2, Black H1, White L3, then Black gets to push at 50. White 52 should be at G13 to attack on the upper side.
I think that is as in the following diagram.
- Click Here To Show Diagram Code
[go]$$W
$$ +--------------------------------------+
$$ | . . . . . . . . . . . 2 . . . . . . .|
$$ | . . . X . . . . . 1 X O X . . O . . .|
$$ | . . . X O . . . 3 X O X . . X O X X .|
$$ | . . X O . . . . . , O . . X . X O X .|
$$ | . . X O . O . . . O . . . . . . O . .|
$$ | . . X . . . . . . . . . . . . . O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . , . . . . . , . . . . . O . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . O . . . . . . . . . . . . .|
$$ | . . X . . . . . . X . . . . . . . . .|
$$ | . . . . . X . . . . . . X . . . O . .|
$$ | . . X , O O O . . X . . . . 4 O . . .|
$$ | . . . X X O . . . . . . O . X O . . .|
$$ | . . . . . . . . . . . . . . . X O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]
John Fairbairn wrote:
White 52 should be at G13 to attack on the upper side.
Sounds like pro advice. I can think of waiting in a line at EGC for a pro to review my own game and then they come to a situation like this and say "Vital point!", "Attack first!", "Very good!", and "Oh no!" and "Maybe OK" when they see the game move. KataGo seems to think it is not forceful.
- Click Here To Show Diagram Code
[go]$$W Review move and KataGo's response.
$$ +--------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . X . . . . X . X O X . . O . . .|
$$ | . . . X O . . . . X O X . . X O X X .|
$$ | . . X O . . . . . , O . . X . X O X .|
$$ | . . X O . O . . . O . . . . . . O . .|
$$ | . . X . . . . . . . . . . . 2 . O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . , . . . . . , . . . . . O . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . O . . . . . . 1 . . . . . .|
$$ | . . X . . . . . . X . . . . . . . . .|
$$ | . . . . . X . . . . . . X . . . O . .|
$$ | . . X , O O O . . X . . . . O O . . .|
$$ | . . . X X O . . . . . . O . X O . . .|
$$ | . . . . . . . . . . . . . . . X O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]
At first KataGo indicated many acceptable moves in the game position but after checking them one by one something that is certainly similar to the game stands out. The difference is that white takes an important forcing move (blocks or slows down black's access to the center, or just prevents a good black move?) and then goes directly for
. Leaving out the game move is the principle of playing C instead of A-B-C. Black's corner is softer when the A-B hasn't been played.
The need for
might not have been on white's radar and he is otherwise basically handling the situation similarly to what KataGo suggests. The difference is rather small in terms of evaluation.
- Click Here To Show Diagram Code
[go]$$W KataGo suggestion which is similar to the game.
$$ +--------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . X . . . . X . X O X . . O . . .|
$$ | . . . X O . . . . X O X . . X O X X .|
$$ | . . X O . . . . . , O . . X 2 X O X .|
$$ | . . X O . O . . . O . . . . 1 . O . .|
$$ | . . X . . . . . . . . . . . . . O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . , . . . . . , . . . . . O . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . 3 . O . . . . . . . . . . . . .|
$$ | . . X . . . . . . X . . . . . . . . .|
$$ | . . . . . X . . . . . . X . . . O . .|
$$ | . . X , O O O . . X . . . . O O . . .|
$$ | . . . X X O . . . . . . O . X O . . .|
$$ | . . . . . . . . . . . . . . . X O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]
John Fairbairn wrote:
White 66 could also have been at 75, then Black E11, White F13.
Maybe this is why I bother replying with all the diagrams. The suggestion is to cut but white invests too much in this attack. Normally the good way to attack is to take some profit first. The opposite is to trade something for the attack, sometimes referred to as "bribing your opponent", that way you can struggle to get back what you paid up front. KataGo says black is just fine but I think the point is that white isn't fine. Maybe the reviewer suggests this for the reader to think about.
- Click Here To Show Diagram Code
[go]$$W
$$ +--------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . X . . . . X . X O X . . O . . .|
$$ | . . . X O . . . . X O X . . X O X X .|
$$ | . . X O . . . . . , O . . X . X O X .|
$$ | . . X O . O . . . O . . . . . . O . .|
$$ | . . X . . . . . . . . . . . . . O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . , . . . . . , . . . . X O . . .|
$$ | . . . . . . . . . . . . O 1 2 . . . .|
$$ | . . . . . . . . . O . O X 4 X . . . .|
$$ | . . . O . O . . . . . O 5 3 6 . . . .|
$$ | . . X X O . . . . X . . . X 7 . . . .|
$$ | . . X O . X . . . . . . X . . . O . .|
$$ | . . X , O O O . . X . X . . O O . . .|
$$ | . . . X X O . . . . . 8 O . X O . . .|
$$ | . . . . . . . . 0 . . . 9 . . X O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]
John Fairbairn wrote:
White 72 was a mistake. He had to push in at 75, then Black E11, White H10, to take away Black's eyes. The capture with Black 73 and 75 makes the big group safe. After this, Black had a lead on the balance of territories and so could wrap the game up with boundary plays.
That is something I noticed too and it is very instructive: Don't just let the opponent's groups become safe.
- Click Here To Show Diagram Code
[go]$$W Reviewer suggestion with a KataGo continuation
$$ +--------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . X . . . . X . X O X . . O . . .|
$$ | . . . X O . . . . X O X . . X O X X .|
$$ | . . X O . . . . . , O . . X . X O X .|
$$ | . . X O . O . . . O . . . . . . O . .|
$$ | . . X . . . . . . . . . . . . . O . .|
$$ | . . . . . . . . . . . . . . 5 . . . .|
$$ | . . . . . . . . . . . 8 . 4 O . . . .|
$$ | . . . . . . . . . . . 6 7 0 X O . . .|
$$ | . . . , . . . . . , . 3 X 9 X O . . .|
$$ | . . . . . . . . . . . . O 1 2 . . . .|
$$ | . . . . . . . . . O . O X . X . . . .|
$$ | . . . O . O . . . . . O . . . . . . .|
$$ | . . X X O . . . . X . . . X . X . . .|
$$ | . . X O . X . . . . . . X . . . O . .|
$$ | . . X , O O O . . X . X . . O O . . .|
$$ | . . . X X O . . . . . . O . X O . . .|
$$ | . . . . . . . . . . O . . . . X O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]
The variation or the timing is not perfect from KataGo's perspective but instructive. A move earlier, which is move 70, it suggests something it considers slightly better. I think it wants to try to hang in there and keep the game close on points, which is usually a good idea. It suggests the following way.
- Click Here To Show Diagram Code
[go]$$W
$$ +--------------------------------------+
$$ | . . . . . . . . . . . 4 . . . . . . .|
$$ | . . . X . . . . X . X O X . . O . . .|
$$ | . . . X O . . . . X O X 3 . X O X X .|
$$ | . . X O . . . . . , O 5 6 X 8 X O X .|
$$ | . . X O . O . . . O . . . . 7 . O . .|
$$ | . . X . . . . . . . . . . . . . O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . X O . . .|
$$ | . . . , . . . . . , . 9 2 . X O . . .|
$$ | . . . . . . . . . . . . O 0 . 1 . . .|
$$ | . . . . . . . . . O . O X . X . . . .|
$$ | . . . O . O . . . . . O . . . . . . .|
$$ | . . X X O . . . . X . . . X . X . . .|
$$ | . . X O . X . . . . . . X . . . O . .|
$$ | . . X , O O O . . X . X . . O O . . .|
$$ | . . . X X O . . . . . . O . X O . . .|
$$ | . . . . . . . . . . O . . . . X O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]
- Click Here To Show Diagram Code
[go]$$Wm11
$$ +--------------------------------------+
$$ | . . . . . . . . . . . X . . . . . . .|
$$ | . . . X . . . . X . X . X . . O . . .|
$$ | . . . X O . . . . X O X O . X O X X .|
$$ | . . X O . . . . . , O O X X X X O X .|
$$ | . . X O . O . . . O . . . . O . O . .|
$$ | . . X . . . . . . . . . . . . . O . .|
$$ | . . . . 4 . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . 3 . . . . . . . .|
$$ | . . . . . . . . . . . . 2 . X O . . .|
$$ | . . . , . . . . . , . O X . X O . . .|
$$ | . . . . . . . . . . . 1 O X . O . . .|
$$ | . . . . . . . . . O . O X . X . . . .|
$$ | . . . O . O . . . . . O . . . . . . .|
$$ | . . X X O . . . . X . . . X . X . . .|
$$ | . . X O . X . . . . . . X . . . O . .|
$$ | . . X , O O O . . X . X . . O O . . .|
$$ | . . . X X O . . . . . . O . X O . . .|
$$ | . . . . . . . . . . O . . . . X O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]
White first strengthens the side with
and finishes by enclosing one side of the center with
. Black is practically alive and the evaluation is B+5.2. The difference to the reviewers variation (B+7.3) isn't much.
I'm confused how KataGo will keep this position so close. The reviewer suggestion might be better for myself. I think I understand that KataGo wants to avoid giving something up for keeping black from being too easily alive and it suggests a way that has white take some profit first but black is practically alive anyway (as far as I can tell).
Maybe those are two different approaches to playing when slightly behind. Reviewer logically (because that is what you do) wants to prevent black from having a completely safe group since safety for black leads to an endgame-like situation, KataGo wants to keep the game as close as possibly and force the black group to defend later and is very confident of its endgame.