Page 3 of 12

Re: Shapes to remember (SDK level)

Posted: Fri Apr 17, 2020 8:58 am
by jlt
Position #17. I was White, 6k+ on IGS, playing a 2-stone handicap game against a 7k.
Click Here To Show Diagram Code
[go]$$Wc White to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O O X . . . . . . . . . . . O X . |
$$ | . . O X X O . . . . . X . . . X O X . |
$$ | . . O X . . . . X , . . . X . X O X . |
$$ | . . . X . . . . . . . . . . . X X O . |
$$ | . . O X . . . . . . . . . . . O O . O |
$$ | . . O O . . . . . . . . . . . . . O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . O X O . . |
$$ | . . . , . . . . . , . . . X O X . . . |
$$ | . . . . . . . . . . . . O O X . X . . |
$$ | . . . . . . . . . . . . X O X . . . . |
$$ | . . . . . . . . . . . O O X X . . . . |
$$ | . . X . X . . . . . . . X O . . O . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . X X O . . . , . . . . . O . . . |
$$ | . X X O X O . . . . X . . X . . O . . |
$$ | . . O O O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Hint: Black's last move was
Q11
Answer:
Do not block at Q12, otherwise Black can atari at P12, then at R12, then capture R11.
Click Here To Show Diagram Code
[go]$$Wc answer
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O O X . . . . . . . . . . . O X . |
$$ | . . O X X O . . . . . X . . . X O X . |
$$ | . . O X . . . . X , . . . X . X O X . |
$$ | . . . X . . . . . . . . . . . X X O . |
$$ | . . O X . . . . . . . . . . . O O . O |
$$ | . . O O . . . . . . . . . . 3 . . O . |
$$ | . . . . . . . . . . . . . . 1 2 . . . |
$$ | . . . . . . . . . . . . . . O X W . . |
$$ | . . . , . . . . . , . . . X O X . . . |
$$ | . . . . . . . . . . . . O O X . X . . |
$$ | . . . . . . . . . . . . X O X . . . . |
$$ | . . . . . . . . . . . O O X X . . b . |
$$ | . . X . X . . . . . . . X O . a O . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . X X O . . . , . . . . . O . . . |
$$ | . X X O X O . . . . X . . X . . O . . |
$$ | . . O O O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Extend at :w1:. Do not be afraid of Black's push :b2:, continue with :w3:.
White doesn't have eyes, but is pretty safe and has a strong wall in the center. The marked white stone is not dead, so Black is not safe either and needs to add a defensive move at "a" or "b".

Re: Shapes to remember (SDK level)

Posted: Sun Apr 19, 2020 9:09 am
by Uberdude
jlt, I will add my own example in a similar vein to your collection if you don't mind. Sdk should be able to get it right, but I got it wrong in a handicap game I just played. I had correctly assumed my shape was connected, but when my opponent played a move which shouldn't have worked my shape intuition was wrong and I answered too quickly and boom, I made a 20+ point mistake and lost the game.
Click Here To Show Diagram Code
[go]$$Bc White to connect
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O O . . . . . . . . X X O O . . |
$$ | . . O X X X X X . X X X X O X O X . . |
$$ | . . O O O O X . X , . . X O O X O O . |
$$ | . . X X X O O X O X X X O . . X . . . |
$$ | . . X . . X . . . . O X O . O . X . . |
$$ | . O X X X . . . . X . O O . . . . . . |
$$ | . O X . . . . . . . . 3 . . X X X . . |
$$ | . . O X . . X . O 1 . . . . X O O X . |
$$ | . O . X . . . . . 2 O O . . X X O X . |
$$ | . . O O . . . . . O X . . . X O . O X |
$$ | . O X . X . . . . O X . O X X O O . O |
$$ | . O X . X . . . . O X X X X O O O O . |
$$ | O X O O X . X X . O O X O . O X O X O |
$$ | O X X . . . X O O O X O O . O X O X X |
$$ | . O X X X X O X X , X X O . O X X . X |
$$ | . O O O X O O O X . X O . O O O X X . |
$$ | . . . . O O O X . . X O . . O X X . X |
$$ | . . . . . . . X . . . . O O . . . . . |
$$ ---------------------------------------[/go]
Click Here To Show Diagram Code
[go]$$Bc Woops
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O O . . . . . . . . X X O O . . |
$$ | . . O X X X X X . X X X X O X O X . . |
$$ | . . O O O O X . X , . . X O O X O O . |
$$ | . . X X X O O X O X X X O . . X . . . |
$$ | . . X . . X . . . . O X O . O . X . . |
$$ | . O X X X . . . . X . O O . . . . . . |
$$ | . O X . . . . . . . . 3 4 . X X X . . |
$$ | . . O X . . X . O 1 . . 5 . X O O X . |
$$ | . O . X . . . . . 2 O O . . X X O X . |
$$ | . . O O . . . . . O X . . . X O . O X |
$$ | . O X . X . . . . O X . O X X O O . O |
$$ | . O X . X . . . . O X X X X O O O O . |
$$ | O X O O X . X X . O O X O . O X O X O |
$$ | O X X . . . X O O O X O O . O X O X X |
$$ | . O X X X X O X X , X X O . O X X . X |
$$ | . O O O X O O O X . X O . O O O X X . |
$$ | . . . . O O O X . . X O . . O X X . X |
$$ | . . . . . . . X . . . . O O . . . . . |
$$ ---------------------------------------[/go]
Click Here To Show Diagram Code
[go]$$Bc Fine
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O O . . . . . . . . X X O O . . |
$$ | . . O X X X X X . X X X X O X O X . . |
$$ | . . O O O O X . X , . . X O O X O O . |
$$ | . . X X X O O X O X X X O . . X . . . |
$$ | . . X . . X . . . . O X O . O . X . . |
$$ | . O X X X . . . . X . O O . . . . . . |
$$ | . O X . . . . . . . 4 3 . . X X X . . |
$$ | . . O X . . X . O 1 . . . . X O O X . |
$$ | . O . X . . . . . 2 O O . . X X O X . |
$$ | . . O O . . . . . O X . . . X O . O X |
$$ | . O X . X . . . . O X . O X X O O . O |
$$ | . O X . X . . . . O X X X X O O O O . |
$$ | O X O O X . X X . O O X O . O X O X O |
$$ | O X X . . . X O O O X O O . O X O X X |
$$ | . O X X X X O X X , X X O . O X X . X |
$$ | . O O O X O O O X . X O . O O O X X . |
$$ | . . . . O O O X . . X O . . O X X . X |
$$ | . . . . . . . X . . . . O O . . . . . |
$$ ---------------------------------------[/go]

Re: Shapes to remember (SDK level)

Posted: Sun Apr 19, 2020 9:54 am
by jlt
Interesting problem. I think another move works.
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O O . . . . . . . . X X O O . . |
$$ | . . O X X X X X . X X X X O X O X . . |
$$ | . . O O O O X . X , . . X O O X O O . |
$$ | . . X X X O O X O X X X O . . X . . . |
$$ | . . X . . X . . . . O X O . O . X . . |
$$ | . O X X X . . . . X . O O . . . . . . |
$$ | . O X . . . . . . . . 3 . . X X X . . |
$$ | . . O X . . X . O 1 . . 4 . X O O X . |
$$ | . O . X . . . . . 2 O O . . X X O X . |
$$ | . . O O . . . . . O X . . . X O . O X |
$$ | . O X . X . . . . O X . O X X O O . O |
$$ | . O X . X . . . . O X X X X O O O O . |
$$ | O X O O X . X X . O O X O . O X O X O |
$$ | O X X . . . X O O O X O O . O X O X X |
$$ | . O X X X X O X X , X X O . O X X . X |
$$ | . O O O X O O O X . X O . O O O X X . |
$$ | . . . . O O O X . . X O . . O X X . X |
$$ | . . . . . . . X . . . . O O . . . . . |
$$ ---------------------------------------[/go]

Re: Shapes to remember (SDK level)

Posted: Sun Apr 19, 2020 10:04 am
by Bill Spight
Click Here To Show Diagram Code
[go]$$Wc Stubborn resistance
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O O . . . . . . . . X X O O . . |
$$ | . . O X X X X X . X X X X O X O X . . |
$$ | . . O O O O X . X , . . X O O X O O . |
$$ | . . X X X O O X O X X X O . . X . . . |
$$ | . . X . . X . . . . O X O . O . X . . |
$$ | . O X X X . . . . X 3 O O . . . . . . |
$$ | . O X . . . . . 7 5 1 B 2 . X X X . . |
$$ | . . O X . . X . O B 4 6 . . X O O X . |
$$ | . O . X . . . 9 8 W O O . . X X O X . |
$$ | . . O O . . . . 0 O X . . . X O . O X |
$$ | . O X . X . . a . O X . O X X O O . O |
$$ | . O X . X . . . . O X X X X O O O O . |
$$ | O X O O X . X X . O O X O . O X O X O |
$$ | O X X . . . X O O O X O O . O X O X X |
$$ | . O X X X X O X X , X X O . O X X . X |
$$ | . O O O X O O O X . X O . O O O X X . |
$$ | . . . . O O O X . . X O . . O X X . X |
$$ | . . . . . . . X . . . . O O . . . . . |
$$ ---------------------------------------[/go]
a = :w11:

Re: Shapes to remember (SDK level)

Posted: Tue Apr 21, 2020 9:51 am
by jlt
Position #19. White to play.
Click Here To Show Diagram Code
[go]$$Wc White to play
$$ ---------------------------------------
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . O . O X . . . . . . . . . . . . . . |
$$ | . . O X . X . . . . . . . . . . . . . |
$$ | . . O , . . . X . X . . . . . O . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . . O O O . . |
$$ | . . . X . . . . . . . . X . X X . . . |
$$ | . . . . . O . . . . O . . . . . X . . |
$$ | . . . . . O X . . . . O . . . X . . . |
$$ | . . X X X O . X . X . . . . O O X X . |
$$ | . . O O . O . . . . . O . . . . O O . |
$$ | . . . . . O X . . . X O . . . . . . . |
$$ | . . . . . . . . . . X X O . . . . . . |
$$ ---------------------------------------[/go]
Possible answer.
Click Here To Show Diagram Code
[go]$$Wc answer
$$ ---------------------------------------
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . O . O X . . . . . . . . . . . . . . |
$$ | . . O X . X . . . . . . . . . . . . . |
$$ | . . O , . . . X . X . . . . . O . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . . O O O . . |
$$ | . . . X . . . c . . . . X . X X . . . |
$$ | . . . . . O . 7 . . O . . . . . X . . |
$$ | . . . . . O X . . . . O . . . X . . . |
$$ | . . X X X O . X . X . . . . O O X X . |
$$ | . . O O . O . 6 5 3 1 O . . . . O O . |
$$ | . . . . . O X . 4 2 X O a b . . . . . |
$$ | . . . . . . . . . . X X O . . . . . . |
$$ ---------------------------------------[/go]
In the game I played b, but Katago thinks it is 5 points worse than :w1:. If Black chooses to respond locally at :b2:, then Black only has one eye. Instead of playing :b2: at K2, Black may prefer to escape at c.

Re: Shapes to remember (SDK level)

Posted: Wed Apr 22, 2020 12:42 pm
by jlt
I got promoted to IGS 5k after an undeserved victory: my opponent resigned while being 1 point ahead according to KataGo. Anyway, here is a joseki question, extracted from the game. The answer should be pretty obvious, but I was careless and played a wrong move. In general I play the opening quite fast in order to save time for the middle game but that's probably a bad habit, it would be better to consider several possible josekis and choose the most appropriate one.

Position #20: Black to answer locally.
Click Here To Show Diagram Code
[go]$$Bc Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . W . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . O . . . . . . . . . . . O X . . |
$$ | . . O , . . . . . , . . . . . , X . . |
$$ | . . . . X . . . X . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Answer:
Click Here To Show Diagram Code
[go]$$Bc Correct answer
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . 1 2 O . . |
$$ | . . . O . . . . . . . . . . . O X . . |
$$ | . . O , . . . . . , . . . 3 . , X . . |
$$ | . . . . X . . . X . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
(It is also possible to tenuki and approach at F17, both moves are equivalent according to KataGo.)

In the game I played at O3 but that's too low, all my stones on the bottom side were on the third line. Black needs to get to the center!

Re: Shapes to remember (SDK level)

Posted: Mon Apr 27, 2020 9:58 am
by jlt
After winning 15/15 games on Fox at 3k level, I got double-promoted to 1k... but then I was afraid that the games would become too difficult so I came back to my 2k Tygem account, to see if I get stuck or if I can manage to rank up there as well.

In the following position I didn't see immediately that Black can play at "a" (White cannot respond at "b", otherwise Black plays "c") but that's not my point. The question is: how to attack White's two stones on the bottom. The answer is rather elementary but I didn't find it during the game.

Position #21: Black to attack the marked white group.
Click Here To Show Diagram Code
[go]$$Bc Black to attack the marked stones
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O O O . O O . O O X . . . . . X . . |
$$ | . X O X . . X O O X X . . . . X . O . |
$$ | . . X X . . X X X O . . . . . . . . . |
$$ | . . . X . . . . . X . . . . . . O . . |
$$ | . . X O . . . . . . . . . . . X . . . |
$$ | . . X O . O . . O . . . . . X O O . . |
$$ | . O O X O . . O . . . . . . X X O . . |
$$ | . . O X O . O X . , . . . . . O O . . |
$$ | . . O X O . . X . . . . . . . . X . . |
$$ | . O X X . O O X . . . . . . . . . . . |
$$ | . O O X X X X . . . . . . . . . . . . |
$$ | . . X O X . . . . . . . . . . . . . . |
$$ | . . . O X O . . . . . . . . . X . . . |
$$ | . . . O X O X . . , . . . . . , . . . |
$$ | . . c O X X . X . W . . W . . X . . . |
$$ | . . b a . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Answer:
Click Here To Show Diagram Code
[go]$$Bc That's it
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O O O . O O . O O X . . . . . X . . |
$$ | . X O X . . X O O X X . . . . X . O . |
$$ | . . X X . . X X X O . . . . . . . . . |
$$ | . . . X . . . . . X . . . . . . O . . |
$$ | . . X O . . . . . . . . . . . X . . . |
$$ | . . X O . O . . O . . . . . X O O . . |
$$ | . O O X O . . O . . . . . . X X O . . |
$$ | . . O X O . O X . , . . . . . O O . . |
$$ | . . O X O . . X . . . . . . . . X . . |
$$ | . O X X . O O X . . . . . . . . . . . |
$$ | . O O X X X X . . . . . . . . . . . . |
$$ | . . X O X . . . . . . . . . . . . . . |
$$ | . . . O X O . . . f . b a . . X . . . |
$$ | . . . O X O X . . , c . . . . , . . . |
$$ | . . . O X X . X . W . . W 3 . X . . . |
$$ | . . . . . . . . . . d e 2 1 g . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
:b1: :w2: :b3: expands Black's corner territory while attacking.
After that, White needs to defend at "a" or "b", otherwhite Black will hane at the head of two stones while expanding his corner. White is not safe yet because of the weak point at "c".

In the game I played "f" (after also considering "d" and "e"), thinking this also indirectly protects the cut at H7 but this is not a good attack because White doesn't even need to respond: in case Black plays again in the area, White may still defend at "g" or escape in the center.

Re: Shapes to remember (SDK level)

Posted: Thu May 07, 2020 4:38 am
by jlt
Position #22: from a blitz game, White to play. The move is not difficult to find but not high enough in my "policy network".
Click Here To Show Diagram Code
[go]$$Wc White to play
$$ ---------------------------------------
$$ | . O X . O . . . . . . . . . . . . . . |
$$ | X O X X O X . . . . . . . O O . . . . |
$$ | . X X O O X . . . X X . O . X O O . . |
$$ | X X X O . X . . . X O O . . X X X . . |
$$ | O X O . . . . . . . . . . . . . . . . |
$$ | O O . O . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . . O . . . |
$$ | . . O . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , X . O . . , . . . . . , . X . |
$$ | . . X . X . . . . . . . . . . . O . . |
$$ | . . . X O O . . . . . . . . O . . . . |
$$ | . X X O X . . . . . . O O . . . O . . |
$$ | . O O O . . . . . . . O X X . X O . . |
$$ | . . . . . O . X . . O X . . . X X O . |
$$ | . . . O . . . . . , O X . . . X O O . |
$$ | . . O . . X . . X . . O X X . . X O . |
$$ | . . . X . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Click Here To Show Diagram Code
[go]$$Wc anti-bump
$$ ---------------------------------------
$$ | . O X . O . . . . . . . . . . . . . . |
$$ | X O X X O X . . . . . . . O O . . . . |
$$ | . X X O O X . . . X X . O . X O O . . |
$$ | X X X O . X . . . X O O . . X X X . . |
$$ | O X O . . . . . . . . . . . . . . . . |
$$ | O O . O . . . . . . . . . . . 1 . . . |
$$ | . . . . . O . . . . . . . . . O . . . |
$$ | . . O . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , X . O . . , . . . . . , . X . |
$$ | . . X . X . . . . . . . . . . . O . . |
$$ | . . . X O O . . . . . . . . O . . . . |
$$ | . X X O X . . . . . . O O . . . O . . |
$$ | . O O O . . . . . . . O X X . X O . . |
$$ | . . . . . O . X . . O X . . . X X O . |
$$ | . . . O . . . . . , O X . . . X O O . |
$$ | . . O . . X . . X . . O X X . . X O . |
$$ | . . . X . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Bumping into an opponent's stone is a move I don't consider enough. This sequence is like bumping, with the order of moves reversed. Maybe this should be called "anti-bumping"?

Re: Shapes to remember (SDK level)

Posted: Thu May 14, 2020 3:08 am
by jlt
Position #23: Black to play. What are the interesting areas on the board? In which area should Black play first?
Click Here To Show Diagram Code
[go]$$Bc Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X O . . . . . . . . . . . . . . |
$$ | . . . X X O . . . O . . . O O X . . . |
$$ | . . . X O O . . . , . . O X . X . . . |
$$ | . . . . . . . . . . . . . X . . X . . |
$$ | . . X X . . . . . . . . . . . X O . . |
$$ | . X O . . . . . . . . . . X X O O . . |
$$ | . . O . . . . . . . . . . . O . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . O . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . X . . . . . . . . . . . . . O O . . |
$$ | . O X X X . . . . , . . O O O X O . . |
$$ | . O O O O X X X . . . X . X X X X . . |
$$ | . . . . . O O . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Katago's answer:
Click Here To Show Diagram Code
[go]$$Bc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X O . . . . . . . . . . . . . . |
$$ | . . . X X O . . . O . . . O O X . . . |
$$ | . . . X O O . . . , . . O X . X . . . |
$$ | . . . . . . . . . . . . . X . 3 X . . |
$$ | . . X X . . . . . . . . . . 2 X O . . |
$$ | . X O . . . . . . . . . . X X O O . . |
$$ | . 5 O . . . . . . . . . . 1 O . . . . |
$$ | . . . . . . . . . . . . . . 4 . . . . |
$$ | . . . , 7 . . . . , . . . . . , . . . |
$$ | . . O . . . . . . . . . . . . . O . . |
$$ | . . . . 6 . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . X . . . . . . . . . . . . . O O . . |
$$ | . O X X X . . . . , . . O O O X O . . |
$$ | . O O O O X X X . . . X . X X X X . . |
$$ | . . . . . O O . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
In the game I played directly at :b7: but Katago's suggestion seems to be superior for the following reasons.

First, :b1: is double-sente. If Black doesn't play there, White cuts at :w2:, Black connects with :b3: and White has a forcing move at :b1:.

Then, :b5: takes off White's base and is almost reverse-sente. If Black doesn't play there, White can settle down easily by playing at :b5: himself.

The stone :b1: may help :b7: in the future.

Re: Shapes to remember (SDK level)

Posted: Thu May 14, 2020 3:19 am
by Bill Spight
The different areas of the board are not independent, although one is almost so. Anyway, it is still a good idea, I think, to consider how play might go in each identifiable region.
I would have picked the crawl as most urgent.

Re: Shapes to remember (SDK level)

Posted: Sun May 24, 2020 6:51 am
by jlt
Finally I got promoted to Tygem 1k, after 17W and 13L. Need to work on elementary tesuji, as I missed the move in the following position.

Position #24: White to play.
Click Here To Show Diagram Code
[go]$$Wc White to play
$$ ---------------------------------------
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . X X X O . O . . . . . . . . . . . . |
$$ | . O O O X O . . . . . . . . . X O O . |
$$ | . . X X X . . . . , . . . O . O X X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . . , . . . . . , . . . . . O O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . . . . . . . . . . . . O . O O . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . O . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . , . . . X . X . . . |
$$ | . . . . . X . . X . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Click Here To Show Diagram Code
[go]$$Wc Answer
$$ ---------------------------------------
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . X X X O . O . . . . . . . . . . . . |
$$ | . O O O X O . . . . . . . . 3 X O O . |
$$ | . . X X X . . . . , . . . O . O X X . |
$$ | . . . . . . . . . . . . . . . 1 . a . |
$$ | . . . . . . . . . . . . . O . X 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |[/go]
:w1: threatens a, so Black needs to respond at :b2:, and then :w3: captures the cutting stone.

Re: Shapes to remember (SDK level)

Posted: Sun May 24, 2020 3:15 pm
by Knotwilg
It seems that there is freedom in the order of play:
Click Here To Show Diagram Code
[go]$$Wc White to play
$$ ---------------------------------------
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . X X X O . O . . . . . . . . 2 5 . . |
$$ | . O O O X O . . . . . . . . 1 X O O . |
$$ | . . X X X . . . . , . . . O . O X X . |
$$ | . . . . . . . . . . . . . . . 3 . . . |
$$ | . . . . . . . . . . . . . O . X 4 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . . , . . . . . , . . . . . O O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . . . . . . . . . . . . O . O O . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . O . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . , . . . X . X . . . |
$$ | . . . . . X . . X . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Click Here To Show Diagram Code
[go]$$B Black resists
$$ ---------------------------------------
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . X X X O . O . . . . . . . . X 3 1 . |
$$ | . O O O X O . . . . . . . . O X O O 5 |
$$ | . . X X X . . . . , . . . O . O X X . |
$$ | . . . . . . . . . . . . . . . O 4 2 . |
$$ | . . . . . . . . . . . . . O . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . 6 . . X X . . |
$$ | . . . , . . . . . , . . . . . O O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . . . . . . . . . . . . O . O O . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . O . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . , . . . X . X . . . |
$$ | . . . . . X . . X . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Re: Shapes to remember (SDK level)

Posted: Mon May 25, 2020 2:23 am
by Uberdude
Knotwilg, I wouldn't want to give black the choice to trade corner for side because it makes the top side open and when White gets the corner Black's side group is still not 100% alive (s13).

Re: Shapes to remember (SDK level)

Posted: Mon May 25, 2020 3:41 am
by Bill Spight
In the FWIW department, there is also a loose ladder. ;)
Click Here To Show Diagram Code
[go]$$Wc Loose ladder
$$ ---------------------------------------
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . X X X O . O . . . . . 9 8 5 3 . . . |
$$ | . O O O X O . . . . . . 7 6 4 X O O . |
$$ | . . X X X . . . . , . . . O . O X X . |
$$ | . . . . . . . . . . . . . . . 1 . . . |
$$ | . . . . . . . . . . . . . O . X 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . . , . . . . . , . . . . . O O . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . . . . . . . . . . . . O . O O . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . O . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . O . . . . . , . . . X . X . . . |
$$ | . . . . . X . . X . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Re: Shapes to remember (SDK level)

Posted: Mon May 25, 2020 5:04 am
by Knotwilg
Uberdude wrote:Knotwilg, I wouldn't want to give black the choice to trade corner for side because it makes the top side open and when White gets the corner Black's side group is still not 100% alive (s13).
I like the first order of moves better too, for the reasons you mention. (But the AI said so!)