Learning how to deal with the L-groups

PeterPeter · Post by **PeterPeter** » Tue Feb 19, 2013 12:19 pm

On Sensei's Library, you can find information on the status and vital points of various L-groups in the corner (L+1 group, L+2 group, Long L group), and their variations (is the leg on the long or the short side, etc). I can see how it would be very useful to know about all of these. But how to approach it?

Do you memorise them? If so, at what kyu level do you do that? They all look rather similar, and not particularly easy to remember, so are there any easy mnemonics?

Or do you read them out each time you encounter them? At 15kyu, how long should it take to read one? I find them quite difficult to read, does that mean I should give priority to lots of reading practice rather than playing full games?

Li Kao · Post by **Li Kao** » Tue Feb 19, 2013 12:33 pm

I'm a 3k, I don't have them memorized, and I can't read them(or at least I don't in a typical game).

emeraldemon · Post by **emeraldemon** » Tue Feb 19, 2013 12:37 pm

You should definitely practice reading them, but the basic progression isn't complicated: L group is dead, L+1 group is unsettled, L+2 group is alive. It's very similar to the 6-7-8 on the 2nd line progression.

SoDesuNe · Post by **SoDesuNe** » Tue Feb 19, 2013 12:39 pm

I would like to answer in one word: Don't! But I'm not sure if this wouldn't count as two since it's the abbreviation of "do not".

Seriously, if you have to think about memorising Tsumegos to remember the vital point then you are most like not strong enough yet to really solve them. I would just go along with your everyday Tsumego book and with increasing difficulty you will naturally face the various L-shapes. Over time you will just solve them by instict, just due sheer repitition.
If you really want a thorough work on L-shapes and such, I can recommend Life&Death from the Elemtary Go series.

And yes, I would always prioritizing reading practice, but this could be a personal thing ; )

jts · Post by **jts** » Tue Feb 19, 2013 12:43 pm

Memorization is quite hard and probably fruitless. As you mention, tiny changes in the shape make a huge difference... and some players have trouble spotting even big differences!

For example, the other day I was playing a handicap game with a 4k, and after I invaded the corner my opponent said, "Ah, the L Group! So the corner is dead, right?"

Click Here To Show Diagram Code: [go]$$B Corner $$ ------------------ $$ | . . . . . . . . . $$ | . . O X . . . . . $$ | . . O X . . . . . $$ | . . O X . . . . . $$ | . O O X . . . . . $$ | . X X . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . . $$ | . . . . . . . . .[/go]

>_>

<_<

I have made much worse mistakes in the past, with other groups. (The "tripod" group, the "comb" group, the "door" group, the six-space eye, "bent four in the corner"...)

So anyway, I think there has to be a sort of reciprocal growth between your own ability to read out the killing variations, and your ability to remind yourself what sequence you are looking for by learning some key facts by heart. When you are starting out, it's enough to know the the "legs" on either side make it easier for the L-group to live. Do more tsumego, keep playing, return to the L-group, and eventually you'll get to a point where "memorizing" is only a slight transition from "knowing very well".

Do you already know things like how many stones you need to live on the second line? These sequences are more fundamental than the L-group and more reasonable study goals, given your reading ability. See SixDieButEightLive

skydyr · Post by **skydyr** » Tue Feb 19, 2013 1:04 pm

I find it useful to know the expected outcome of a situation in the corner without having to read it, and I suggest you learn that at some point, just like you've probably learned the basic dead shapes to the point that you don't even think about them: Bulky 5? should die, for example. However, I don't recommend sitting down and memorizing the various ways to kill, etc. Knowing the status should give you enough information to read it out when you encounter it and your opponent disagrees/plays a ko threat without using too much of your time.

That said, I'm not sure how useful it would be before you reach, say, 9 or 10 kyu. There are much more fundamental things to work on instead, and knowing those basics will help you read the situations when they arise, including the various tricks and issues caused by incomplete connections, extra liberties, and so forth.

Bill Spight · Post by **Bill Spight** » Tue Feb 19, 2013 1:05 pm

PeterPeter wrote:On Sensei's Library, you can find information on the status and vital points of various L-groups in the corner (L+1 group, L+2 group, Long L group), and their variations (is the leg on the long or the short side, etc). I can see how it would be very useful to know about all of these. But how to approach it?

Do you memorise them?

When I learned go, I thought that memorization was a bad idea. Now I am not so sure. :scratch:

If so, at what kyu level do you do that?

If you do memorize, I think the earlier, the better.

Whether the L-groups is where to start is another question. For life and death, I would start with the nakade.

When I started out, this is one of the things I learned. White to play in all three corners.

I have omitted the answers, so that you can have fun playing around with these positions. Enjoy!

Edit: Oops! :oops:

There is something you probably need to be told, that you cannot be expected to figure out for yourself. See later post.

Or do you read them out each time you encounter them? At 15kyu, how long should it take to read one?

At 15 kyu I think that you should average around 10 sec. per move. If you need more time for reading, I would suggest 30 sec. max. But find your own pace.

I find them quite difficult to read, does that mean I should give priority to lots of reading practice rather than playing full games?

No.

IMHO, there is a similarity to learning a language. Should a 2 year old pick up vocabulary or practice grammar? At 15 kyu, you still learn a lot just by playing. You can also pick up good ideas by kibitzing stronger players. Look at the positions in the SGF file. Do you think that all six possible first plays are equal? If all you have to go by is reading, they are. One or more points should stand out. If you have no sense of potentially good and bad plays, reading is just following a maze of variations.

By all means analyze. By all means play around. But that's not the same as reading.

SoDesuNe · Post by **SoDesuNe** » Tue Feb 19, 2013 1:08 pm

I have to confess I also confuse the L- and J-group all the time :O

post scriptum:

Bill Spight wrote:
PeterPeter wrote:On Sensei's Library, you can find information on the status and vital points of various L-groups in the corner (L+1 group, L+2 group, Long L group), and their variations (is the leg on the long or the short side, etc). I can see how it would be very useful to know about all of these. But how to approach it?

Do you memorise them?

When I learned go, I thought that memorization was a bad idea. Now I am not so sure. :scratch:

Interesting!

Nice status-problems, as well : )

topazg · Post by **topazg** » Tue Feb 19, 2013 1:19 pm

FWIW, as an anecdote from my experiences:

I never learned the shapes by rote. I learned that L is dead, L+1 is unsettled, L+2 is alive around 5k. It wasn't long after that an L+2 of mine died because it was actually an L+2 with a descent, and I hadn't a clue that changed things because I'd learned it the "wrong" way.

If you can't read it, don't worry about it - if the shape comes up in one of your games (or something that looks like it), read, trust your judgement, learn if you got it wrong. Rinse and repeat.

I wouldn't have had a clue at 10k about the shapes in Bill's post, but I know the answers now at a glance without explicit memorisation or reading the positions out. Experience creates a sort of ambient memory of shapes that will supercede rote learning, and I have a feeling that rote learning would actually get in the way of that process.

Uberdude · Post by **Uberdude** » Tue Feb 19, 2013 1:44 pm

I know by heart that L is dead (and hanes make no difference), L+1 unsettled (and some hanes make a difference but I don't know which), L+2 alive (except descent on long side leaves a long ko), J unsettled (plus hane makes alive), straight J is ko, J+1 alive (and the other descent from L+2 is sente to kill, so depending which descent you don't want to give in sente to your opponent you choose to live with L+2 or J+1). I never learned any of the sequences by heart so do that reading in the game, but probably some of the easier ones I have done so many times (e.g. killing a J group) I barely need to read to play them.

HermanHiddema · Post by **HermanHiddema** » Tue Feb 19, 2013 1:47 pm

Uberdude wrote:I know by heart that L is dead (and hanes make no difference), L+1 unsettled (and some hanes make a difference but I don't know which), L+2 alive (except descent on long side leaves a long ko), J unsettled (plus hane makes alive), straight J is ko, J+1 alive (and the other descent from L+2 is sente to kill, so depending which descent you don't want to give in sente to your opponent you choose to live with L+2 or J+1). I never learned any of the sequences by heart so do that reading in the game, but probably some of the easier ones I have done so many times (e.g. killing a J group) I barely need to read to play them.

Heh, I know *exactly* the same things! :lol:

Uberdude · Post by **Uberdude** » Tue Feb 19, 2013 1:55 pm

P.S. And the carpenter's square is a ko but I'll learn that one ~~once I'm a dan player~~ later.

Bill Spight · Post by **Bill Spight** » Tue Feb 19, 2013 2:03 pm

OK. Here are the answers.

Along with a variation that gets into rules questions. :shock:

Bill Spight · Post by **Bill Spight** » Tue Feb 19, 2013 2:10 pm

Uberdude wrote:I know by heart that L is dead (and hanes make no difference), L+1 unsettled (and some hanes make a difference but I don't know which), L+2 alive (except descent on long side leaves a long ko), J unsettled (plus hane makes alive), straight J is ko, J+1 alive (and the other descent from L+2 is sente to kill, so depending which descent you don't want to give in sente to your opponent you choose to live with L+2 or J+1). I never learned any of the sequences by heart so do that reading in the game, but probably some of the easier ones I have done so many times (e.g. killing a J group) I barely need to read to play them.

L group? J group? What are those?

Dusk Eagle · Post by **Dusk Eagle** » Tue Feb 19, 2013 2:44 pm

I disagree with some of the other comments here. I think memorizing positions such as the L-group and J-group is very useful. To be able to read a long sequence until it ends up in a known position and then instantly recognize, "This group can be killed from here," really helps the accuracy of my reading. I would recommend memorizing them (either conciously or subconciously, as I suspect many stronger players have) at some point, as long as you also memorize or understand the various positions that go along with killing or living with these groups. I personally memorized them when I was 5k and felt a definite jump in my skill level around that time, and I probably could've benefited from learning them even earlier.

Life In 19x19

Learning how to deal with the L-groups

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