Proper corner play?

Aidoneus · Post by **Aidoneus** » Wed Aug 06, 2014 5:21 pm

I've tried finding this cut by White at eidogo.com and ps.waltheri.net to no avail. I've experimented with extending, descending, and playing atari with rather disappointing results considering that it seems like it must be a very bad move to not appear at all in pro games or Kogo's dictionary. I hope that someone will be willing to give some variations or at least discuss what may be wrong with White's cut! Thank you in advance.

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Post by **Solomon** » Wed Aug 06, 2014 5:47 pm

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DrStraw · Post by **DrStraw** » Wed Aug 06, 2014 6:00 pm

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W has a dead shape. If W now plays 'a' then B has to play in the corner to kill and so W has aji on the outside. But this early in the game it is hard to see how to use it. This means W's cut is too aggressive at this stage. With other stones on the board it may be possible to consider it.

Aidoneus · Post by **Aidoneus** » Wed Aug 06, 2014 7:07 pm

Yeah, I guess that context is everything. I tried the descent earlier today. I thought that White was dead till

. Suddenly, it seemed that I waited too long, or tenukied too much. So, I switched to trying to capture the outside group with

. I spent a lot of time thinking about it and thought that it would work, but it failed, or maybe I just went wrong. I played on a little while more, but I knew that I was lost.

This was my first 19 x 19 game in several days. I've been squeezing in a few 9 x 9 igowin games between finishing up spruce-up work around the house before going back to teaching. I think that I'll buy Attack & Defense with my first check.

Shawn Ligocki · Post by **Shawn Ligocki** » Wed Aug 06, 2014 7:40 pm

Hi Aidoneus, I think your descent was good, but some of the follow-up plays were the real problem.

Note that in the normal Joseki, White gets life in sente so even if you kill in gote that could be a big improvement! But notice that you actually try to take sente by tenukiing at

. I haven't read this fully, but if you kill White and get sente, that is huge! and you should expect that White will get some advantage from the fight at least (and that the fight should be hard). Also note that at this point White's corner is in trouble, but your 2 groups are weak and cut, so they are not very safe either. You might want to play another move here rather than tenuki to guarantee that White is dead.

But the really glaring problems are

and

. You are being too greedy and creating 4(!) weak groups for your opponent to attack. If she kills any, that is a huge loss for you!

Instead of

, what about B2 (makes miai of C2 and A3)? Simply C2 may work as well. In either case, you have a shortage of liberties to worry about, but I think you are one move ahead.

As I mentioned above, this would be easier to read if you had not tenukied back at

, if you don't want to have a dangerous fight at

, then you can be happy to kill White's invasion in gote back in the early game.

Aidoneus · Post by **Aidoneus** » Thu Aug 07, 2014 1:14 am

Shawn Ligocki wrote:Hi Aidoneus, I think your descent was good, but some of the follow-up plays were the real problem.

Note that in the normal Joseki, White gets life in sente so even if you kill in gote that could be a big improvement! But notice that you actually try to take sente by tenukiing at . I haven't read this fully, but if you kill White and get sente, that is huge! and you should expect that White will get some advantage from the fight at least (and that the fight should be hard). Also note that at this point White's corner is in trouble, but your 2 groups are weak and cut, so they are not very safe either. You might want to play another move here rather than tenuki to guarantee that White is dead.

But the really glaring problems are and . You are being too greedy and creating 4(!) weak groups for your opponent to attack. If she kills any, that is a huge loss for you!

Instead of , what about B2 (makes miai of C2 and A3)? Simply C2 may work as well. In either case, you have a shortage of liberties to worry about, but I think you are one move ahead.

As I mentioned above, this would be easier to read if you had not tenukied back at , if you don't want to have a dangerous fight at , then you can be happy to kill White's invasion in gote back in the early game.

Hi Shawn,

Yeah, I looked first at

at c2 but after

at b2 I thought that I was too short of liberties. I actually spent most of the 7 minutes I took for this move looking at

at b2,

at c2, and

at a3 before giving it up as hopeless because of shortage of liberties again after

at b1,

at a2,

at f2. I guess that I misread that position in my head! (I really stink at corner L&D problems. I'm still working through the elementary problems from Cho Chikun's Encyclopedia of L&D at http://tsumego.tasuki.org/.)

Besides creating weak groups, the only thing I really know how to do is play gote moves.

I'm desperately trying to sense when I can safely tenuki instead of following all the time.

Thank you for your comments!

EdLee · Post by **EdLee** » Thu Aug 07, 2014 4:00 am

Hi Aidoneus,

Aidoneus wrote:I'm desperately trying to sense when I can safely tenuki instead of following all the time.

This is non-trivial.
It's an on-going quest. It requires knowledge and experience
in all aspects of Go: life-and-death, vital points, direction,
urgent v. big, shapes, tesujis, ko, sente & gote, liberties,
counting, assessment of the situation, attack & defense,
fighting skills, reading in general, end game, etc.
That's why it's so difficult! And it's related to your weak groups
management, too. Enjoy.

Uberdude · Post by **Uberdude** » Thu Aug 07, 2014 4:45 am

A few years ago there was an 8d on KGS called takemeba who liked to play the side hoshi points and tengen for his first moves and let his opponent play in all 4 corners. He would then invade their 4-4 at 3-3 and if the opponent hane'd after block and crawl he would cut. The support of the two neighbouring side hoshis means you can't kill the corner, and having lived there his opponent was cut and would invariably suffer in the fighting that followed. Probably in such a situation hane was overplay and should just be extend.

Aidoneus · Post by **Aidoneus** » Thu Aug 07, 2014 5:20 am

Hi Ed, Uberdude, et al.:

I was too wenrou, so now I try too hard for xianshou. With a little help from my friends, I may get by or at least not drive into a ditch.

Thanks,
Bill

skydyr · Post by **skydyr** » Thu Aug 07, 2014 6:29 am

Unless I'm misreading, I'm pretty sure black can still win the capturing race at

if he plays to capture with A10. It's 4 liberties to 4 liberties, so this has been big and unsettled for a while. White will connect under with the corner, but it's still the loss of a string of 10 stones or so for white that also connects all of black's groups locally. Alternatively, black may be able to take the corner by playing B2, but he will probably lose the outside group of 4 stones in exchange, which would save the 11 white stone group.

Bill Spight · Post by **Bill Spight** » Thu Aug 07, 2014 6:50 am

Aidoneus wrote:I'm desperately trying to sense when I can safely tenuki instead of following all the time.

When you are not sure whether to tenuki or not, tenuki. If you are wrong, you will probably find out in the resulting fight, but if you take gote when you should not, no bell rings.

Shawn Ligocki · Post by **Shawn Ligocki** » Thu Aug 07, 2014 7:01 am

Aidoneus wrote: Hi Shawn,

Yeah, I looked first at at c2 but after at b2 I thought that I was too short of liberties. I actually spent most of the 7 minutes I took for this move looking at at b2, at c2, and at a3 before giving it up as hopeless because of shortage of liberties again after at b1, at a2, at f2. I guess that I misread that position in my head! (I really stink at corner L&D problems. I'm still working through the elementary problems from Cho Chikun's Encyclopedia of L&D at http://tsumego.tasuki.org/.)

Oops, you're right. That doesn't quite work for black in the way I expected. Nice reading!

Besides creating weak groups, the only thing I really know how to do is play gote moves. I'm desperately trying to sense when I can safely tenuki instead of following all the time.

Yes, this is a great thing to try in your games! And a slow road of learning for all of us. But now that you've had a chance to review your own game, here's the question: do you think you should have tenukied? Or kept playing locally?

The fact that you would not be able to tenuki the normal joseki tells you that killing in gote is probably still an improvement. This is a useful trick I am trying to use more in my own games. To compare to the line if play you expected. If the new line is better, you have successfully punished your opponent for a misplay.

Aidoneus · Post by **Aidoneus** » Thu Aug 07, 2014 7:29 am

skydyr wrote:Unless I'm misreading, I'm pretty sure black can still win the capturing race at if he plays to capture with A10. It's 4 liberties to 4 liberties, so this has been big and unsettled for a while. White will connect under with the corner, but it's still the loss of a string of 10 stones or so for white that also connects all of black's groups locally. Alternatively, black may be able to take the corner by playing B2, but he will probably lose the outside group of 4 stones in exchange, which would save the 11 white stone group.

Hi skydyr,

I spent about 3.5 minutes on

to convince myself that I would lose the capturing race because of White's cut. So, I gave up on capturing. Unfortunately, I spent only 7 seconds to play :90:, instead of seeing that I could have captured White with

at a10! (Right?) But if this is so, I don't understand why the program allowed this possibility. (I'm used to computer chess where tactical mistakes are almost nonexistent.)

@Shawn: So, for a player of my limited skill, I probably should have killed White before leaving the area earlier. (I still have trouble sometimes distinguishing between when a group is mostly dead and all dead. Which leads me at times to waste moves when groups seem slightly alive to me. An opportunity to call out to The Princess Bride fans!)

DrStraw · Post by **DrStraw** » Thu Aug 07, 2014 9:27 am

Bill Spight wrote:
Aidoneus wrote:I'm desperately trying to sense when I can safely tenuki instead of following all the time.
When you are not sure whether to tenuki or not, tenuki. If you are wrong, you will probably find out in the resulting fight, but if you take gote when you should not, no bell rings.

I would add to this that even if it is dangerous to tenuki then by doing so there is a good chance the opponent will follow you where you move anyway and you can come back to it later. The habit is low kyu players is that they always think their opponents last move is sente.

Bill Spight · Post by **Bill Spight** » Thu Aug 07, 2014 12:31 pm

A few comments.

Edit: Added a couple of variations.

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Proper corner play?

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