Life In 19x19 :: Where to invade

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Where to invade http://www.lifein19x19.com/viewtopic.php?f=11&t=11396	Page 1 of 1

Author:	gostudent [ Sun Jan 25, 2015 12:51 am ]
Post subject:	Where to invade
When I reviewed my games that I lost recently, I realized that there is a common theme: I often pick a wrong spot in invasion or in reduction, leading to either dead groups or my opponent get a lot of points elsewhere. An example is the following. I invaded at (a) in the game, but that gave white extra points in the bottom, as white pincered at (b) subsequently. I have three questions. (i) Is it right for black to invade at the bottom? (ii) If black wants to invade at the bottom anyway, what would be some good options? (iii) How can one become better in judging when to invade, and once invaded find plays to make enough shapes to live? Click Here To Show Diagram Code [go]$$B $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . X . . . . . . . X . . \| $$ \| . . X , . . . . . , . . . X . X . O . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . O . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . O . . \| $$ \| . . . X . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . O X . . . \| $$ \| . . O . . . . . . . . O . . O X . . . \| $$ \| . . . . . . . . . . . . . . . O X . . \| $$ \| . . . O . . . . . , . . X O . O X . . \| $$ \| . . . . . . . b . . . O O X O . X . . \| $$ \| . . . a . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go]

Author:	Uberdude [ Sun Jan 25, 2015 3:49 am ]
Post subject:	Re: Where to invade
It sounds to me like you expect to get too much from your invasions. It's reasonable for black to invade the botton but also it is fair for wait to get a lot of points in the process because he started with many more stones in that area and is very strong on the right. Black has some nice territory elsewhere on the board, go is a sharing game.

Author:	Bill Spight [ Sun Jan 25, 2015 3:57 am ]
Post subject:	Re: Where to invade
Uberdude wrote: It sounds to me like you expect to get too much from your invasions.

Author: Bill Spight [ Sun Jan 25, 2015 4:27 am ]

Post subject: Re: Where to invade

gostudent wrote:

When I reviewed my games that I lost recently, I realized that there is a common theme: I often pick a wrong spot in invasion or in reduction, leading to either dead groups or my opponent get a lot of points elsewhere.

An example is the following. I invaded at (a) in the game, but that gave black extra points in the bottom, as black pincered at (b) subsequently.

I have three questions.

(i) Is it right for black to invade at the bottom?

Maybe.

But note that if White seals the corner with E-03, Black can still reduce the White framework.

Quote:

(ii) If black wants to invade at the bottom anyway, what would be some good options?

Too many possibilities. In a game that takes an hour, it would be reasonable to spend several minutes on this position.

Quote:

(iii) How can one become better in judging when to invade, and once invaded find plays to make enough shapes to live?

To quote Watson, THINK!

Judgement does not come easily. Experience matters. Try ideas out.

Don't be greedy.

One important point is that you do not have to live.

You can sacrifice stones for aji. You can live with some of your stones, while you give up others.

Click Here To Show Diagram Code: [go]$$Bc Did it go this way? $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . X . . . . . . . X . . | $$ | . . X , . . . . . , . . . X . X . O . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . X . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . O X . . . | $$ | . . O . . . . . . . . O . . O X . . . | $$ | . . . . . . . . . . . . . . . O X . . | $$ | . . . O . . . . . , . . X O . O X . . | $$ | . . 2 . . 3 . 4 . . . O O X O . X . . | $$ | . . . 1 . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

There is your invasion and his pincer.

If it did go that way, I think that :b3:

was a mistake. ( :b1:

, I don't know.)

Click Here To Show Diagram Code: [go]$$Bc Better $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . X . . . . . . . X . . | $$ | . . X , . . . . . , . . . X . X . O . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . X . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . O X . . . | $$ | . . O . . . . . . . . O . . O X . . . | $$ | . . . . . . . . . . . . . . . O X . . | $$ | . . . O . . . . . , . . X O . O X . . | $$ | . . 2 . C . 3 . b a . O O X O . X . . | $$ | . . . 1 . C . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

After

I think that :b3:

is the play. For one thing, it has a possible extension to "a". For another, it is lighter than F-03. Also, it has a diagonal relationship to :b1:

, indicated by the marked points. (One reason that the diagonal relationship is important for sabaki is to make eye shape.

) Important point: You do not have to save :b1:

. It has done a good job by inducing :w2:

Click Here To Show Diagram Code: [go]$$Bc Miai $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . X . . . . . . . X . . | $$ | . . X , . . . . . , . . . X . X . O . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . X . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . . . . . . . . . . . . . O X . . . | $$ | . . O . . . . . . . . O . . O X . . . | $$ | . . . . . . 3 . . . . . . . . O X . . | $$ | . . . O . . . C . , . . X O . O X . . | $$ | . . . . 2 . 1 . . b . O O X O . X . . | $$ | . . . a . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Another thought is to invade at 1, making miai of "a" and "b". One thing. If :w2:

may be better than "b", because White is so strong to the right. Not exactly miai.

Note that

has a diagonal relationship with :b1:

Click Here To Show Diagram Code: [go]$$Bc Reduction $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . X . . . . . . . X . . | $$ | . . X , . . . . . , . . . X . X . O . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . O . . | $$ | . . . X . . . . . , . . . . . , . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . X . . . | $$ | . . b . 3 . . . . . . . . . O X . . . | $$ | . . O . . C . . . d . O . . O X . . . | $$ | . . . . . . 1 . . . . . . . . O X . . | $$ | . . . O . . . . . c . . X O . O X . . | $$ | . . . . . . 2 . . . . O O X O . X . . | $$ | . . . . a . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ ---------------------------------------[/go]

Another idea is a reduction with :b1:

, aiming at 2. Now if :w2:

, Black can jump out with :b3:

(diagonally related), which aims at "b". Black still has play on the bottom side, at "c" and "d", for example (all diagonally related).

All of these plays are diagonally related to the same points. There is another set of possibilities diagonally related to "a".

Author:	gostudent [ Sun Jan 25, 2015 6:09 pm ]
Post subject:	Re: Where to invade
Bill Spight wrote: gostudent wrote: When I reviewed my games that I lost recently, I realized that there is a common theme: I often pick a wrong spot in invasion or in reduction, leading to either dead groups or my opponent get a lot of points elsewhere. An example is the following. I invaded at (a) in the game, but that gave black extra points in the bottom, as black pincered at (b) subsequently. I have three questions. (i) Is it right for black to invade at the bottom? Maybe. But note that if White seals the corner with E-03, Black can still reduce the White framework. Quote: (ii) If black wants to invade at the bottom anyway, what would be some good options? Too many possibilities. In a game that takes an hour, it would be reasonable to spend several minutes on this position. Quote: (iii) How can one become better in judging when to invade, and once invaded find plays to make enough shapes to live? To quote Watson, THINK! Judgement does not come easily. Experience matters. Try ideas out. Don't be greedy. One important point is that you do not have to live. You can sacrifice stones for aji. You can live with some of your stones, while you give up others. Click Here To Show Diagram Code [go]$$Bc Did it go this way? $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . X . . . . . . . X . . \| $$ \| . . X , . . . . . , . . . X . X . O . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . O . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . O . . \| $$ \| . . . X . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . O X . . . \| $$ \| . . O . . . . . . . . O . . O X . . . \| $$ \| . . . . . . . . . . . . . . . O X . . \| $$ \| . . . O . . . . . , . . X O . O X . . \| $$ \| . . 2 . . 3 . 4 . . . O O X O . X . . \| $$ \| . b a 1 . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] Yes, it was almost what happened in the game, though I made an exchange of (a) and (b) first before jumping out to 3. When I viewed it now, I am not sure if that exchange is a good idea -- the exchange ended up to be useful because I tried to create a living group there, but maybe I committed to live there too early. Bill Spight wrote: There is your invasion and his pincer. If it did go that way, I think that was a mistake. ( , I don't know.) Click Here To Show Diagram Code [go]$$Bc Better $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . X . . . . . . . X . . \| $$ \| . . X , . . . . . , . . . X . X . O . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . O . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . O . . \| $$ \| . . . X . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . O X . . . \| $$ \| . . O . . . . . . . . O . . O X . . . \| $$ \| . . . . . . . . . . . . . . . O X . . \| $$ \| . . . O . . . . . , . . X O . O X . . \| $$ \| . . 2 . C . 3 . b a . O O X O . X . . \| $$ \| . . . 1 . d . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] After I think that is the play. For one thing, it has a possible extension to "a". For another, it is lighter than F-03. Also, it has a diagonal relationship to , indicated by the marked points. (One reason that the diagonal relationship is important for sabaki is to make eye shape. ) Important point: You do not have to save . It has done a good job by inducing . I have played this move in a similar situation before, but my opponent answered by playing at (d), and I was no longer able to connect my two white stones. So I tried to play one space closer. Based on your feedback, I don't really need to connect the two stones. Perhaps I can reply to (d) by pretending to try to connect to 1, getting a line of three white stones in the process, and then jumping out? Bill Spight wrote: Click Here To Show Diagram Code [go]$$Bc Miai $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . X . . . . . . . X . . \| $$ \| . . X , . . . . . , . . . X . X . O . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . O . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . O . . \| $$ \| . . . X . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . O X . . . \| $$ \| . . O . . . . . . . . O . . O X . . . \| $$ \| . . . . . . 3 . . . . . . . . O X . . \| $$ \| . . . O . . . C . , . . X O . O X . . \| $$ \| . . . . 2 . 1 . . b . O O X O . X . . \| $$ \| . . . a . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] Another thought is to invade at 1, making miai of "a" and "b". One thing. If , may be better than "b", because White is so strong to the right. Not exactly miai. Note that has a diagonal relationship with . Click Here To Show Diagram Code [go]$$Bc Reduction $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . X . . . . . . . X . . \| $$ \| . . X , . . . . . , . . . X . X . O . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . O . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . O . . \| $$ \| . . . X . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . X . . . \| $$ \| . . b . 3 . . . . . . . . . O X . . . \| $$ \| . . O . . C . . . d . O . . O X . . . \| $$ \| . . . . . . 1 . . . . . . . . O X . . \| $$ \| . . . O . . . . . c . . X O . O X . . \| $$ \| . . . . . . 2 . . . . O O X O . X . . \| $$ \| . . . . a . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] Another idea is a reduction with , aiming at 2. Now if , Black can jump out with (diagonally related), which aims at "b". Black still has play on the bottom side, at "c" and "d", for example (all diagonally related). All of these plays are diagonally related to the same points. There is another set of possibilities diagonally related to "a". For the last variation, aren't 1 and 3 elephant jump, and thus it is often not a bad move? I have actually read some examples on good elephant jump, but I have never been able to figure out when it is good to do an elephant jump.

Author:	DrStraw [ Sun Jan 25, 2015 6:21 pm ]
Post subject:	Re: Where to invade
[quote="gostudent"] Click Here To Show Diagram Code [go]$$B $$ --------------------------------------- $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . X . . . . . . . X . . \| $$ \| . . X , 1 . . . . , . . . X . X . O . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . O . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . O . . \| $$ \| . . . X . . . . . , . . . . . , . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . X . . . \| $$ \| . . . . . . . . . . . . . . O X . . . \| $$ \| . . O . . . . . . . . O . . O X . . . \| $$ \| . . . . . . . . . . . . . . . O X . . \| $$ \| . . . O . . . . . , . . X O . O X . . \| $$ \| . . . . . . . . . . . O O X O . X . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ \| . . . . . . . . . . . . . . . . . . . \| $$ ---------------------------------------[/go] Something to think about: if you were to strengthen the upper left with a move like :B1 how would you evaluate the situation? Black has a solid lower right. Does white have enough more potential than black after this move? I think not. It is even at best and I would prefer to play black. Don't just invade because you see a moyo forming. See what moves you have and evaluate the relative size and strengths of opposing moyos.

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