[Study Group] Essential Life and Death Patterns

Users that have reached the “trust level” of “regular” can turn their own posts into wikis that can be edited by almost everyone (except for new users, I guess to prevent spam). Since you (@Gia) are a “regular”, you can do this as well. Click on the icon that looks like three dots on any of your recent posts, then click on the wrench icon, and you will get the option to turn your post into a wiki.

@bugcat, I’ve been making my more recent posts (unfortunately, it does not seem possible for me to edit or convert older posts into wikis) in this thread wikis in case others wished to add to them, or to correct any mistakes. I’m hoping that this thread would be more of a discussion where we all work through life and death shapes together, but I feel like my presentation style in the older posts might have made things more like a series of lectures. So, I’m trying something different to see if that might increase participation.

Update: thank you to @flovo for helping to convert the older posts in this thread into wikis.

Note: I’ve consolidated a couple of older posts into the original post.


Does this work?

I don’t think so.

42, 21, 12 kills. 13 and 41 are miai to prevent black from forming a 2nd eye.

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If it’s black to play, I’m fairly confident that A17 lives. I’m not sure what the best result white can get if it’s white to play.


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With white to play, does this kill?

No, and I’m fairly sure the refutation is the same.


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I already knew the status of the tripod group but I had to check Sensei’s for the details.

How do we do spoilers btw?

[details="Title of spoiler"]
You are spoiled

Will result in >

Title of spoiler

You are spoiled

There is also a convenient shortcut under the cog button (which is not intuitive at all, I agree)


I know about the summary function, but I can’t use that in the middle of a line of text. I tried and it didn’t work.

Well, then just don’t? :smiley: I am sorry I am not sure what the question is then. Yes, it is impossible to use in the middle of the line, and there is no way to work around it (that I know of).

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Something < spoiler>like this< /spoiler> doesn’t work?

Without the spaces. That’s how I’ve always done it in Disqus.

Edit: it’s also supposed to show a blur option where the poll is, but I usually use the tag, so I don’t remember exactly, but my guess would be it needs to be turned on by an admin.

Turn on dark theme!!!



I want to share some thoughts about why are these patterns important for progress (more so than other life-and-death problems)?

  1. They are the result of typical corner invasion sequences. You still have to learn the invasion sequence but it helps to know the result is alive at a glance. More subtly, you know the standard shapes and look for sequences that build them.
  2. They are essential for more advanced life-and-death. When a sequence ends up with a group you know is dead, you can stop reading early and discard the sequence.

Simple example : take a L+1 group. If you play hane on the “+1” side, you get a L group which is dead. Problem solved.
If I have the time, I’ll share a few such sequences for 1. later.


L group in actual play:

Look at the bottom right group starting at move 9. My opponent played for the “natural” defending moves which end in a L-group, probably not recognising it was dead, and giving me an easy game.

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Shape 9: One-Space Notchers

Not really a single shape, but rather a family of shapes, which are in turn part of an even larger family of shapes. See also the Table of Notchers (link posted by @bugcat earlier).




Spoiler Proverb

“Four die, Seven live”
or, alternatively,
“Five and Six are unsettled”

Note: weaknesses and liberties also affect the status

Status in the corner?