A vague treatise on influence
Posted: Fri Feb 10, 2012 3:59 am
I thought I'd offer some comments on my opinion of influence, for those that want to agree, disagree, discuss, or verbally abuse me about 
So, what is influence?
In many ways, I think it's reasonable to say that any stone exerts influence on the board around it, even a 1-1 stone. The problem is, we all know that a) influential play is reasonable, and b) playing on the 1-1 is bad pretty much all of the time, so understanding more about how to use influence seems key to make comments like "3rd line for territory, 4th line for influence" actually turn into a game strategy that makes sense. I've noticed that, in general, the weaker end of the player spectrum seems to really struggle with influence based games, because territory is that much easier to "get".
The winner of a Go game is, obviously the person who earns more points per stone over the course of 200 or so moves. Territorial play is easy to assess, because you can see the points developing in front of your eyes - influential play however, requires both a patience in investing in the position for the future, and just as importantly, a basic understanding of how to convert that investment into points, something that will rarely happen by itself.
To begin this diatribe, I'm going to outline some definitions I tend to use, because I think they help with clarity of purpose when applied to stones on the board. I tend to differentiate quite strongly between thickness and influence, even though they are very similar. This is because the impact the difference has is quite profound on developing a strategic plan. In short, every stone has influence, which is reduced by nearby opposing stones and increased by nearby friendly stones. Thickness is easiest thought of as an accumulation of influence that exceeds a certain rather arbitrary value. The importance of this is related to the stone investment - because a lot more stones are played to create a thick position, the importance of getting as many "points per stone" (see second paragraph) as possible becomes urgent. It is very rare for a thick position facing across an open side of the board not to have a very high level of urgency for both players to manage promptly. If the thick player succeeds in developing effectively from his position, he should stand to make either a large territory that is worth the number of stones played, or alternatively should be able to construct an attack that achieves the same thing. In contrast, the goal of the player without the thickness should be to force the thick player to become overconcentrated. The punishment is not a crazy squeeze or a dastardly attack, more often than not, it's overconcentration: forcing the opponent to accept a small amount of territory for a large number of played stones.
So, some examples:
In this second diagram, the top after Black's somewhat premature invasion becomes really important. White has created a genuinely thick position - it's both full of stones and with a noticeable lack of weaknesses. As a result, White's extension here is a fairly vital point for Black to be concerned about, and playing simply to prevent it and contribute to the development of the top left Black stone is unlikely to be terrible. In contrast, if Black is to play elsewhere, White's approach to find a cohesive plan at the top that works with his thickness seems eminently reasonable:
Of course, how to implement that plan isn't always obvious, and this returns to the "points per stone" issue. This actually isn't something there's a simple answer for, as it seems the accumulation of experience will teach it with all the caveats and exceptions much more easily than trying to learn it by rote, but in essence, the last diagram is unwise for White as Black can have an easy time making White overconcentrated. The top right White position is "thick", and has plenty of eyespace potential. As a result, it's not really a target, and building two facing walls like this is a good example of "making territory from thickness" being iffy. Instead, White can choose to approach the top left corner directly, where either result is relatively acceptable:
In this situation, White either gets to develop a moyo from his thickness on a suitably large scale for the number of stones invested, or he gets a corner (better than Black's in the top right) in exchange for the thickness. Black's position at the top, prior to
, still has a lot of aji at "x" through "z", whereas White' position at the top right has almost nothing for Black to use as leverage. As such, Black following immediately with has a lot of sense - Whilst it might look like White is building points from thickness by playing at "y", it is likely to do so in sente as the threat of shenanigans against the top Black group is high:
This seems to be risking allowing White to have his cake and eat it, as Black still has some aji issues and not only did White take the corner, but his original thickness has both developed some points and the potential to develop yet further. So, again, Black and White's strategy is focused around the thick positions on the board. Continuing on:
is designed as a pre-emptive protection against "a", as Black's position at the top has solidified to the point where he can play "a" and the corresponding push / squeeze (see hide tag below for the sequence) in the hope of profiting on the left. Alternatively, because of White's thickness in the top right, an alternative could be to work on developing that side of the board, simply because Black, aware of the potential of White creating two directional thickness by bending at "b", will be wanting to approach around "c" as soon as possible. For example:
Top left push sequence:
Continuation of the game example:
The thickness starts to quickly create a position which has some considerable White potential, provided Black doesn't get there first. Strategically, it is again apparent that making the most of thickness (or not) happens in just a few moves, and has a large enough game impact to be urgent enough not to neglect.
So, back to the original points on influence and thickness. I see the two normal outcomes of influential stones as being thickness or territory. If you play territorially to secure a few points or give one of your groups safety, you've taken your result immediately. With an influential move, the outcome is generally unclear until further moves have been played in the area. A 4-4 opening stone is a quintessential example of this, where with another 2 stones you have a big corner, but just as often you'll have a big wall of stones and your opponent will have the corner. That doesn't mean to say you wait for your opponent to dictate to you what you're allowed to have. Sometimes the whole board changes in a way where one result becomes good for you, and the other less good, and you dictate the terms before your opponent gets the chance to. For example:
Here, with
, Black tries to create a situation where an easy path for White becomes much less clear. Prior to , "a" and the extension, a vaguely possible "b", and invasion at "c" and contact fun with "d" all are ideas White might like to throw around. Suddenly, after , White's options become a lot more limited, and all of the remaining ideas give Black more than he could have previously expected. So, the other aspect to think about with influential moves is what to do to develop them, and I think this is probably the point that most kyu players struggle with. Essentially, there is no way out of learning the variations that are possible for each side, as that determines what aji is in a position. From learning that, a good time to develop the position further is when you can change a local miai situation (very common with 4-4 stones) into a local win-win situation (albeit at the cost of allowing your opponent a move elsewhere). The rest is simply timing 
My brain is addled, so I'll stop here, but I figured I'd throw it out there for discussion / debate on the offchance we could get a really good thread going on common examples of influence and development ideas in real games. The ones above are somewhat flawed but just a few of the concepts I thought I could contextually try to get across quickly!
So, what is influence?
In many ways, I think it's reasonable to say that any stone exerts influence on the board around it, even a 1-1 stone. The problem is, we all know that a) influential play is reasonable, and b) playing on the 1-1 is bad pretty much all of the time, so understanding more about how to use influence seems key to make comments like "3rd line for territory, 4th line for influence" actually turn into a game strategy that makes sense. I've noticed that, in general, the weaker end of the player spectrum seems to really struggle with influence based games, because territory is that much easier to "get".
The winner of a Go game is, obviously the person who earns more points per stone over the course of 200 or so moves. Territorial play is easy to assess, because you can see the points developing in front of your eyes - influential play however, requires both a patience in investing in the position for the future, and just as importantly, a basic understanding of how to convert that investment into points, something that will rarely happen by itself.
To begin this diatribe, I'm going to outline some definitions I tend to use, because I think they help with clarity of purpose when applied to stones on the board. I tend to differentiate quite strongly between thickness and influence, even though they are very similar. This is because the impact the difference has is quite profound on developing a strategic plan. In short, every stone has influence, which is reduced by nearby opposing stones and increased by nearby friendly stones. Thickness is easiest thought of as an accumulation of influence that exceeds a certain rather arbitrary value. The importance of this is related to the stone investment - because a lot more stones are played to create a thick position, the importance of getting as many "points per stone" (see second paragraph) as possible becomes urgent. It is very rare for a thick position facing across an open side of the board not to have a very high level of urgency for both players to manage promptly. If the thick player succeeds in developing effectively from his position, he should stand to make either a large territory that is worth the number of stones played, or alternatively should be able to construct an attack that achieves the same thing. In contrast, the goal of the player without the thickness should be to force the thick player to become overconcentrated. The punishment is not a crazy squeeze or a dastardly attack, more often than not, it's overconcentration: forcing the opponent to accept a small amount of territory for a large number of played stones.
So, some examples:
In this second diagram, the top after Black's somewhat premature invasion becomes really important. White has created a genuinely thick position - it's both full of stones and with a noticeable lack of weaknesses. As a result, White's extension here is a fairly vital point for Black to be concerned about, and playing simply to prevent it and contribute to the development of the top left Black stone is unlikely to be terrible. In contrast, if Black is to play elsewhere, White's approach to find a cohesive plan at the top that works with his thickness seems eminently reasonable:
Of course, how to implement that plan isn't always obvious, and this returns to the "points per stone" issue. This actually isn't something there's a simple answer for, as it seems the accumulation of experience will teach it with all the caveats and exceptions much more easily than trying to learn it by rote, but in essence, the last diagram is unwise for White as Black can have an easy time making White overconcentrated. The top right White position is "thick", and has plenty of eyespace potential. As a result, it's not really a target, and building two facing walls like this is a good example of "making territory from thickness" being iffy. Instead, White can choose to approach the top left corner directly, where either result is relatively acceptable:
In this situation, White either gets to develop a moyo from his thickness on a suitably large scale for the number of stones invested, or he gets a corner (better than Black's in the top right) in exchange for the thickness. Black's position at the top, prior to
, still has a lot of aji at "x" through "z", whereas White' position at the top right has almost nothing for Black to use as leverage. As such, Black following immediately with has a lot of sense - Whilst it might look like White is building points from thickness by playing at "y", it is likely to do so in sente as the threat of shenanigans against the top Black group is high:This seems to be risking allowing White to have his cake and eat it, as Black still has some aji issues and not only did White take the corner, but his original thickness has both developed some points and the potential to develop yet further. So, again, Black and White's strategy is focused around the thick positions on the board. Continuing on:
is designed as a pre-emptive protection against "a", as Black's position at the top has solidified to the point where he can play "a" and the corresponding push / squeeze (see hide tag below for the sequence) in the hope of profiting on the left. Alternatively, because of White's thickness in the top right, an alternative could be to work on developing that side of the board, simply because Black, aware of the potential of White creating two directional thickness by bending at "b", will be wanting to approach around "c" as soon as possible. For example:Top left push sequence:
Continuation of the game example:
The thickness starts to quickly create a position which has some considerable White potential, provided Black doesn't get there first. Strategically, it is again apparent that making the most of thickness (or not) happens in just a few moves, and has a large enough game impact to be urgent enough not to neglect.
So, back to the original points on influence and thickness. I see the two normal outcomes of influential stones as being thickness or territory. If you play territorially to secure a few points or give one of your groups safety, you've taken your result immediately. With an influential move, the outcome is generally unclear until further moves have been played in the area. A 4-4 opening stone is a quintessential example of this, where with another 2 stones you have a big corner, but just as often you'll have a big wall of stones and your opponent will have the corner. That doesn't mean to say you wait for your opponent to dictate to you what you're allowed to have. Sometimes the whole board changes in a way where one result becomes good for you, and the other less good, and you dictate the terms before your opponent gets the chance to. For example:
Here, with
, Black tries to create a situation where an easy path for White becomes much less clear. Prior to , "a" and the extension, a vaguely possible "b", and invasion at "c" and contact fun with "d" all are ideas White might like to throw around. Suddenly, after , White's options become a lot more limited, and all of the remaining ideas give Black more than he could have previously expected. So, the other aspect to think about with influential moves is what to do to develop them, and I think this is probably the point that most kyu players struggle with. Essentially, there is no way out of learning the variations that are possible for each side, as that determines what aji is in a position. From learning that, a good time to develop the position further is when you can change a local miai situation (very common with 4-4 stones) into a local win-win situation (albeit at the cost of allowing your opponent a move elsewhere). The rest is simply timing My brain is addled, so I'll stop here, but I figured I'd throw it out there for discussion / debate on the offchance we could get a really good thread going on common examples of influence and development ideas in real games. The ones above are somewhat flawed but just a few of the concepts I thought I could contextually try to get across quickly!
is too close to W.
( 
) jump into 3-3, W could get a good result blocking either side.
.
, driving Black towards the wall. One virtue of such a strong wall is that it hinders the development of the opponent's stones. Versus nirensei an approach from the top drives Black towards a friendly stone. Approaching from the left does not do that. Here the wall pays off by the territory that Black does not get. 
- 
. With such a strong wall I want Black to invade. 
or a.