Yuan Zhou has written a number of pro games commentaries that are easy to read and understand for kyu players. I think it's a good way to have examples of how something like thickness and influence can change the flow of a game. Skillfull play with lots of subtitles

When I think about walls, these are the three main questions I think of:

1. What are walls?

Wall is just that - a wall. If nothing else happens, it will likely become one side of a possibly large territory. So, to prevent this, the opponent will always have to worry about it. This is a good thing.

Another aspect of the wall is strength - although these two ideas are not really the same. Strength allows you to fight in other parts of the board without worrying about the wall/strength coming under attack (as in - splitting attack). This gives you some peace of mind, which is good.

One important thing to note here is that walls and strength are not the same. Some walls can be week, some can be very week. Such walls have much more limited use because you *do* have to worry about them getting under attack and you cannot afford to play freely without worry. So it is important to judge the strength of your wall as well.

But all in all - a wall is a good thing for you and potential trouble for your opponent.

2. How to play with respect to walls?

To me, Go groups (or even stones) are like magnets - except that they all have the same polarity and so repel each other. Generally, the larger a group of stones the more its repelling force - thus you play farther away from it. This goes both for your own groups and for the opponent's groups. Walls are groups wich repel the most (because all the repelling force of all stones is pointed in the same direction), usually, so you try to play away from them.

Of course, as the game progresses, you play closer and closer to other stones/groups. So I think about it as the magnetic 'power' of the stones diminishes over time. Eventually, a moment will come when you be able (or have to) to play close(r) to a wall, be it your wall of your opponent's. The trick is to utilize your own wall before that happens, and prevent your opponent from utilizing his/her.

You can utilize your own walls by trying to play stones which work with the wall, outlining areas or even moyos. This will force your opponent to jump in, hopefully, at which point you can attack. If he/she fails to invade or reduce, the wall will turn directly into points eventually.

Conversely, you will try to prevent your opponent from doing the same to you.

3. How to use a wall?

I already hinted at most of it - you use it for attacking, for peace of mind (fighting elsewhere without worry), and for building territory/moyos.

Most popular way of using a wall is for attack. This combines the concepts above. Because your opponent has to worry that, if nothing is done, the wall will eventually become a side of a large territory, at some point he/she will have to do something about it. This means approaching the wall to minimize its potential. In such situation, the approaching sone can be pincered and might come under attack. The main idea is to push the weak stone towards your wall.

A typical outcome of such fight is not usually death of a group, but maybe another wall, facing in some more advantageous for you direction. You can imagine a series of walls, each created by attacking stones approaching the previous wall, with the last wall eventually being used to make direct points. But sometimes the attacking groups die... or other groups die when you can stage a splitting attack. This all connects to the reasons for attacking and the advantages you can have by doing so - but this is another topic.

Another thing is - there is also a danger that during the course of the game, a wall will become neutralized. This can happen, for example, if your opponent will build his/her own wall facing your wall, or create a strong group in vicinity of your wall. A lot of times this involves such concepts as proper joseki choice or even non-joseki moves. It gets complicated.

And also: Influence?

I was trying to explain how I see walls without using the word 'influence', because this is what everybody else seems to be doing.

But influence is a great way to explain many things in Go, which is why people keep talking about it so much. You can see stones/groups/walls as radiating influence. The concept of neutralizing a wall can be then explained by overlapping spheres influence. If influence is not deal with timely, it might easily become solid points. And so on... Walls create more influence than other kinds groups, so this is one reason they are important to understand.

PS>
Not sure if all this makes any sense... cannot think straight today... just another day at the Bantari office.

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- Bantari
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WARNING: This post might contain Opinions!!

I still don't get this. So after the initial white stone played close to black's wall, black tenukis and white establishes a base. Black can get another free move somewhere else as well. Admittedly white won't get many points here, but so much of blacks potential in the area has been destroyed. And perhaps this is offset by his free moves elsewhere... but a simple pincer after white's initial move lets black easily harry the white stone while developing the right side. If white jumps you can follow for a move or two. Then you can tenuki and take a big move elsewhere. You still let white live, white is still not making territory (even less actually) and you get one fewer free move somewhere else, but I don't see a single move that can create as much potential as the bottom right that you were able to build up. Is this really a good example of where to tenuki a white invasion?

It's not the best example, but consider the board with some bog-standard black moves added elsewhere:

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . B . . . . . . . B . . . . . |
$$ | . . . O . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . B . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . O X . . . . . . . . . . . . . . . . |
$$ | . O X . . . . W . . . . . . . . X . . |
$$ | . . O X . . . . . , . . . . . , . . . |
$$ | . . O X . X . W . . W . . . . X . . . |
$$ | . . O O X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

Who got more with their three moves?


Bear in mind that to make the entire bottom territory, black would have had to spend several moves there as well, and white would still be able to reduce.

I think it's an example of how tenuki may not be a significant mistake, but I have to agree that pincering white is really obvious and strong.

Part of this is that white has already arguably made a mistake by playing the 3-3 invasion so early...and even facing a super strong shimari. In that case it's not really surprising that black does fine, because he can make his own mistakes and still get an even position. I don't want an even position though, as black I want a slightly better one

If white plays these threee moves and black gets 3 of his own (some double approaches or whatever), it does seem fine for black, but I think this misses the point that pincering white is super duper easy and obvious and powerful and seems like what I would definitely want to use the wall for.



Part of the value of the wall is that black wouldn't need many moves to make quite a lot of territory on the bottom. Of course white can still invade even with a black stone in the middle, but such an invasion cannot fail to give black something massive on one side or the other.

Again, I agree that black getting 3 moves makes the game fine for him, but I still think this is mixed up with the issue that black can make mistakes of his own and come out ahead thanks to the early 3-3 invasion, plus that just because black can do fine by tenuki doesn't mean the (clearly also strong) pincer isn't as good or better.

Let me be clear that I agree with amnal here and pincering is the obvious choice, in case it wasn't clear from what I said earlier as well.

Just two interesting semi-classic posts for people new to the forum.

Bill Spight on how to use walls:
viewtopic.php?p=36356#p36356
viewtopic.php?p=38322

John Fairbairn on thickness:
viewtopic.php?p=47787

I think if you are feeling that you don't understand walls and influence, the best tack is to play an extremely territorial strategy for a while. After playing four or five games like this you'll start to feel an unpleasant twist in your stomach when your opponent makes the moves you've started to fear. And that's the point where you're starting to understand how to use influence.

Many people who have trouble deciding what moves are good for them to play, nonethless know with a chilling certainty which moves would be painful for the opponent to play - but of course, what's good for the one is painful for the other, and vice versa.

The consensus is that black ought to just pincer in the example given earlier of where you might use a wall to tenuki. So who has some ideas of how to modify the position slightly such that tenuki is worth considering?

Here's one thought to start things rolling:

Click Here To Show Diagram Code

[go]$$B
$$ +---------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . O . . . . . . . . O , . . . |
$$ | . . . O . . . . . , . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . O . . . . . . . . . . . |
$$ | . O X . . . . . . . . . . . . . . . . |
$$ | . O X . . . . . . . . . . . . . . . . |
$$ | . . O X . . . . . , . . . . . , X . . |
$$ | . . O X . X . W . . . . . . X . . . . |
$$ | . . O O X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ +---------------------------------------+[/go]

White escapes from a pincer easily, so the position doesn't feel urgent to me any more. If black didn't have a wall, he might have to play locally to keep white from playing on the left and sealing him in.

Um... Black is still missing two stones on the board?

That'll teach him not to go to the bathroom without memorizing the board position first.

I agree that black's stones are much more useful here... but is this better than the situation if black pincers the invasion stone? For someone trying to learn how to best use walls and influence I'm struggling with knowing when its better to let an invasion live. It seems like pincering, building up the lower right and then getting sente to play somewhere (?? not sure best move after that) might be just as good or better than this result. Or am I misunderstanding the situation?


But aren't the reasons that it's not urgent for black the same reasons why it might not be urgent for white? The threat of the pincer before was severe and made life for the white stones really difficult. That's one reason why making a base was such a huge move for white. In this position it looks like white has mia... either make a base or run towards the helper stone. Or if nothing else white can play lightly with the invasion stone and reduce. So a lot of the damage to blacks potential is already accomplished and it feels like white can afford to match black's move elsewhere without leaving this situation in too dire a state.

Well, as mentioned, this was a bad example. But it works in that black ends up well off in either situation, so you can see how white's move being too close to thickness was a bad move for white. Whatever black does, white takes a big loss.


Well, as you said, white's move was slow, so black can just take a big point. Missing stones aside, in this position the point one to the right of the right side star point is so gigantically large I can't imagine black wanting anything but it or a similar move.

That was my thought as well, that it look miai, Presumably white played h7, black said "what a weirdo" and tenuki'd, white played the 3-3 invasion out, then white played h3. Black says "didn't there used to be more black stones on the board?" and then tenuki's again. Here it looks like maybe black blocked on the wrong side, although I imagine we could add stones on the left to make a block that way less interesting.

Stepping back, was the original tenuki bad?

Click Here To Show Diagram Code

[go]$$B
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . O . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . X . . . . . ,
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .
$$ | . . . . . . . . . .
$$ +-------------------[/go]

Even if we're determined not to take some other path with the 3-3 invasion, it's hard to believe a local move is urgent for black.

So white invades the 3-3, we end up with the original diagram, and again the area doesn't look urgent for black. So I wouldn't say black let his potential get damaged, I'd say he sold it for two gote moves by white.

And additionally, although white has options the group isn't settled by any means. If a fight spills into the center from any of the other 3 sides, white might be forced to come back and establish a base. So black can calmly wait for a better chance to attack later.

And what if white gets his extension on the bottom and connection and this all just becomes boring yose?

Click Here To Show Diagram Code

[go]$$B
$$ | . O X . . X . O . . . O . . X . . X . |
$$ | . O X . . X . O . . . O . . X . . . . |
$$ | . O X . . X . O . . . O . . X . . . . |
$$ | . . O X . X . O . , . O . . X , X . . |
$$ | . . O X . X . O . . . O . . X . . . . |
$$ | . . O O X . X O . . . O . . X . . . . |
$$ | . . O X X X O O . . . O . . X . . . . |
$$ +---------------------------------------+[/go]

White's position looks hard to develop and not end up over-concentrated.

Basically, I think we can look at white's efforts at counteracting black's influence as greedy, and that black can do fine just taking big points and saying "ok, prove that your moves had value."

It is perhaps not a fantastic example, and as a 9k I would recommend pincering and attacking in any situation remotely like this. However, as you get stronger, your opponents will learn to play a little cautiously around your walls, but you will still be tempted to KILL. These attacks will then often fail and you may end up with a bad result. Judging when it's better to tenuki will take some time to figure out. The point I'm trying to make is that quite often you can accept that your opponent's safe wall-negating move is probably on a dame point, and you can consider it a time to cash in your investment and play a big territorial point somewhere.

Well, in the future I will definitely think about whether it makes more sense to try and use the wall for attack and profit or if it makes more sense to tenuki. Which will be interesting at least.

I would say that you have to completely erase from your mind the idea that this huge outer wall is an attempt to make territory. It's not! It's used to strengthen your ability to attack opponents elsewhere on the board, and in turn, make territory elsewhere.

But it does that partially through the threat of making territory right? I mean if I completely ignore it, it can certainly turn into territory. And the threat that it might is what eventually forces someone into trying to prevent it from easily doing so. And that's when it turns into a great way to attack.

If we imagine that I could immediately plop down a small group that was unequivocally alive that ruined any territory here (without actually taking any moves on my part) then the usefulness of the wall is greatly diminished, correct? I don't have to create some foolhardy invasion to ruin the potential here anymore and I don't have to worry about fights elsewhere helping to make this area into territory. So yes, I can still be attacked by being pushed towards this wall, but without the threat of territory here I'm not likely to want to play near the wall anyway.

If I'm misunderstanding this, could you give me an example of how one would use this wall when the usefulness of this wall for territory has been ruined? Something other than getting free moves attacking the stones that destroyed the potential for territory (as I understand that those moves are a normal use of a wall but rely on the threat of turning a wall into territory which is not what you say walls are for).

Here is an example of a wall dying. Hong Kipyo vs. Lee Changho, Lee went on to win the tournament.