Life In 19x19 :: Review Request - Defending Moyos / Killing Invasions

Life In 19x19 http://www.lifein19x19.com/

Review Request - Defending Moyos / Killing Invasions http://www.lifein19x19.com/viewtopic.php?f=4&t=15808	Page 1 of 1

Author:

00Noles [ Fri Jun 08, 2018 8:51 am ]

Post subject:

Review Request - Defending Moyos / Killing Invasions

Today i played a game on IGS with two Handicap stones against a 12 Kyu. I was quite sure i could be able to win and at first everything seemed fine as i managed to build a real nice moyo at the bottom half of the board, until... Move 59

Now, while something like this seems to happen quite often to me in the last couple of games i thought it might be a good example to request a review. At the thought of beeing to greedy popped up in my head.. "Was this even defendable? Am i claiming to much for my own?". On the other hand it seemed like i just applied what i learned so far (building boxes, should be really hard for the enemy to live inside etc.), so there must be one (or probably more) mistakes i made while defending.

I have to admit, that i had quite a few ideas while reviewing the game myself (see comments in SGF) and that reviewing in in order to upload it here had me do it in a much more conscientious fashion than usual :lol:

Well, enough talking.. i'm excited for your comments and ideas!

Attachments:

FirstReviewL19.sgf [6.21 KiB]
Downloaded 702 times

Author:	Schachus [ Fri Jun 08, 2018 10:08 am ]
Post subject:	Re: Review Request - Defending Moyos / Killing Invasions
As a general comment I would say you are playing too close to the stones you want to attack. As you can see, this might result in your own stones getting in danger and therefore gives him valuable forcing moves to strengthen his group. As you correctly see, defending with 60(and also 62 but less so) was too defensive and covardish, but lets take 63 as the beginning position of things. I think you should try to stay further away from him, to keep him from running away, not attack his eyes immediately. Fist reduce his space, only then kill. Also: your stones on the left are very strong, so your general direction should be to come from the right and press him towards the left. In the process you should be "automatically" going a nice box of territory in the lower right. I would start at k8 or j8, to do that. Your move at f8 is too close to him and your strength. Later, at 88: Why to take that eye?! if you run away at k7 and he makes that eye, doesnt loook like he is gonna get a second one, does it? Actually, you should already run away with 86 instead of cutting(he stil needs to protect the cut, then he doesnt have eyes) and maybe 84 was a little close in the first place, though its quite a tricky move. You see these points also demonstrated in your game: you repeatedly had to look after your own stones, decisively losing some in the end and he did run towards the bottom right, destoying many possible points there.

Author:	00Noles [ Fri Jun 08, 2018 12:18 pm ]
Post subject:	Re: Review Request - Defending Moyos / Killing Invasions
Hey Schachus, thanks for your analysis! I tried a few variations starting with move 63 being played at K8 instead of F6 and (although i'm not very good at finding my opponents best moves in such cases) it seems like, as you said, chances are good for making nice profit on the right while white lives very small. The resulting black wall in the center even seems to offer nice possibilities for reducing whites sector in the upper left. The principles you mentioned are usually quite clear to me during phases of the games where everything is still more balanced and the stakes of battle are not really high (let's say fuseki stage (at least at my level)), but it seems like i often get quite nervous when something rather unexpected/unusual or possibly game deciding happens. I hope i'll have the chance to apply those things in the coming games - even in the heat of battle

Author:	mitsun [ Fri Jun 08, 2018 4:08 pm ]
Post subject:	Re: Review Request - Defending Moyos / Killing Invasions
(F6) looks fine to me. This is a vital point to prevent W from making good shape, it starts to make territory while attacking, and it is strong, not subject to any counter-attack. Surrounding W on a larger scale (somewhere around J9) may be even better, but this move is still really good at your level. Going back earlier, the previous B moves at E10 and C9 and were much worse, hopelessly defensive and submissive. Going back even earlier, those problems all stemmed from , which should be the solid hanging connection at C8. This is the standard way to defend the cutting point, with good shape, leaving no bad aji for your opponent to exploit. (It is a bit high level, but please verify that the hanging connection also defends the weakness at E10. If W cuts there, you should be able to capture the cutting stone in a net, with no need for a ladder.) During the later fight, you were focussed too tightly on preventing W from making eyes, missing the big picture of surrounding and attacking on a large scale. If you surround W globally, yet he manages to live inside on a small scale, while you make territory outside, that would be a great success in this game. Your goal should be to make territory while attacking, not to kill. But if you block each and every W attempt to make an eye, leaving all sorts of weaknesses behind each time, until he manages to either escape or capture part of the attacking force, that is a miserable failure, likely to leave you with too little territory. In line with this: should be around L10, preventing W from escaping. should be around L6 (making immediate territory while attacking) or M9 (forcing W to run toward the bottom, where you plan to make even more territory during a more prolonged attack). Your move was indeed the vital point for preventing eyes, but unless you actually manage to kill W, it is likely to end up as a wasted move. Finally, once you get as much as possible from your attack, and it is clear that W will live, you should keep sente to invade around C17, to see if you can live there. Give W the same problems he has been giving you! (Even better would be to count the game, then just reduce around H14 if your count says that is enough to win.)

Author:	Joaz Banbeck [ Fri Jun 08, 2018 6:16 pm ]
Post subject:	Re: Review Request - Defending Moyos / Killing Invasions
I only had time to make comments up to move 31. ( Maybe more after the NBA finals )

Author:	00Noles [ Fri Jun 08, 2018 9:52 pm ]
Post subject:	Re: Review Request - Defending Moyos / Killing Invasions
Thank you both mitsun and Joaz! As you both pointed it out: i can see now how the "keima-connection" on is quite weak. i recall playing it, because i saw it in an online video or something (in a completely different situation probably ). i thought it would protect the cutting point, while linking up to the 4-4 stone at the bottom. @mitsun If i may generalize what you said about , and it seems like it's ok to occupy shape points as long, as you have some kind of connection to your stones (e.g. connects up to F4 or D5). If not it's better to surround and block the running path. Is this correct? @Joaz Banbeck Thanks for pointing out some earlier mistakes too. I see what weaknesses you refer to at and getting cut or pincered there seems like something that could have totally happened to me (and might have in earlier games ). Hence my overly protective behavior regarding M17 - maybe As you pointed it out several times O11 appears as a very good and solid move to me now (especially as it also protects Q10). I hope i will remember this in my next game!

Author:	mitsun [ Sat Jun 09, 2018 1:16 am ]
Post subject:	Re: Review Request - Defending Moyos / Killing Invasions
If I had to generalize, the basic principle would be to attack from outside. You want to make attacking moves which weaken your opponent, while keeping your own positions strong. Frequently the best way to do this is to play moves which force your opponent to run toward your existing strong positions. And while doing all that, figure out how you can make territory as a natural result of the attacking moves. Best result (but not likely): surround a group, leaving it with too little space to live Good result: surround a group, let it live small, make territory outside Good result: threaten to surround, force group to run in the direction you choose (choose a direction which keeps your groups strong and makes territory while attacking) Examples: in the game prevents W from making eye-space, while immediately taking profit below. If W plays somewhere around H9 to escape, you can continue along the same lines with H7, another nice shape move which makes territory below. By the time W escapes to the top, you will have completed a large territorial framework, while W will have played on dame, escaping but making no territory. at J8 is perhaps a more advanced strategy. This move blocks the natural escape direction for W, forcing him to move awkwardly around this stone. If he runs upward to escape, you plan to use the attack to destroy the W moyo above, getting to play moves like G12 naturally. If he runs downward to live, you plan to consolidate territory below while attacking, getting to play moves like H4 naturally. could be a good move, if you were much stronger at fighting. I would call this a strong but speculative move. I prefer to attack more simply, when there are strong and safe alternatives which avoid complications. Maybe I am just lazy. If you like fighting, go for it. However, if your start this fight, you really have to read as deeply as you can. For example, after you cut at H8, can W simply capture those two stones with K7? That would be a disaster already. When W misses this move, why not escape right away with K7? Now those cutting stones look like they cannot be captured, so W is separated into two weak groups, and at least one of those groups will probably die.

Author:	bernds [ Sat Jun 09, 2018 6:58 am ]
Post subject:	Re: Review Request - Defending Moyos / Killing Invasions
In general, you seem to be focused too much on small areas of the board. One possibility I'd like to mention is that at some point between moves 80 and 100, or even instead of 108, a play like N4 might be good. Surrounds the lower side, and takes away options for White to run away. Take territory while attacking, or just threatening to attack. Leave it to White to figure out if he needs to add stones to his group to live.

Author:

00Noles [ Sun Jun 10, 2018 2:35 am ]

Post subject:

Re: Review Request - Defending Moyos / Killing Invasions

Actually i don't really like (contact) fights occurring in my games, as i feel like i'm not really good at close combat stuff. But i try not avoid them completely so i can improve at fighting (and don't perish peacefully all the time :oops:

)
I think what motivated my aggressive play (block running path and block eye space simultaneously) concerning the white invasion was the fear of this becoming really big. I played a couple of games, were such invasions, while actually making little (living small) or no (running away) points for the enemy became really bulky and forced my stones back in such a way, that my own territory had to suffer remarkably. As i commonly don't have a good clue were to invade the enemy myself (see question below) in the later midgame i felt not very pleasant about that..

But i tried a few variations with the suggested plays. And while of course they are just rough sketches, as white would probably not play that generously, everyone of them seems to produce a very good result for black (not quite what i imagined it would look like during the game :lol:

)

What i would be quite interested in, is what an invasion around C17 (mitsune mentioned it earlier) could possibly look like, as i can hardly imagine how to live around there.
When i glimpse at my side of the board i can totally see, why bernds suggestion to play at N4 during or following one of the variations is a very necessary idea as K4 is high and far away form Q3. C16 and G17 on the contrary seem quite solid to me. Or is there a way to run and connect to H11 :scratch:

Attachments:

FirstReviewL19_alt.sgf [884 Bytes]
Downloaded 592 times

Author:	Bill Spight [ Sun Jun 10, 2018 3:13 am ]
Post subject:	Re: Review Request - Defending Moyos / Killing Invasions
00Noles wrote: Actually i don't really like (contact) fights occurring in my games, as i feel like i'm not really good at close combat stuff. Something to get over as quickly as you can. The majority of plays in go are contact plays, either adjacent or diagonally adjacent to another stone.

Author:	Tapani [ Tue Jun 12, 2018 5:16 am ]
Post subject:	Re: Review Request - Defending Moyos / Killing Invasions
00Noles wrote: Thank you both mitsun and Joaz! As you both pointed it out: i can see now how the "keima-connection" on is quite weak. i recall playing it, because i saw it in an online video or something (in a completely different situation probably ). i thought it would protect the cutting point, while linking up to the 4-4 stone at the bottom. This comment shows lack of insight. You are not (only) trying to protect against a cut. You are protecting against the clamp. Now read out what would happen if your opponent clamped after (and without) your keima cut protection. Instructive, and less painful than having it happen to you in a game And you get ideas what you can do if your opponent does not defend correctly ..

Page 1 of 1	All times are UTC - 8 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/