I have a question regarding when it is OK to be surrounded, particularly in the opening. Generally we like to surround and not be surrounded. However, it’s fine to invade a 3-3 and take a corner, even if that gives the opponent influence in return. I’m sure a lot has to be considered in context (and I don’t have a particular position in mind), but would you say that it’s OK to be surrounded if you are getting enough territory to balance the influence your opponent is getting? In other words, does the territory-influence balance determine when it’s OK or not OK to get surrounded?
Context is kinda everything here, if you do 3-3 invasion into 4-4 corner as move 5 its horrible - influence outweight corner territory significantly. On other hand if you do such invasion at right time influence might have very little value and it is beneficial.
In the opening dont do 3-3 invasions into unless special circumstances happens, but later it can be huge move (you dont only get some points, but also deny opponent more points)
You need to weight your profit against opponents profit, good opportunity for 3-3 invasion would be going into double wing with only 4-4 in corner that have little to no potencial to develop further on sides… but in this case opponent will like to close corner if he have time for it 
Thank you so much for your feedback! What you said about 3-3 invasions makes complete sense.
Suppose there is a middlegame situation where both players have played out toward the center from the sides, and the center is being contested. Your opponent keeps trying to block you out of the center and surround you. My question in this context: under what circumstances would you be OK with that? If you have enough territory in the bank to outweigh what the opponent can get by surrounding you and locking you out of the center, then it seems fine to get surrounded, right? Otherwise, it seems we have to keep trying to stay ahead and not get cut off from the potential territory we need. Am I thinking about this correctly?
This was the old theory. But we now know it wasn’t true. AlphaGo showed us it’s perfectly OK to invade 3-3 under a star point as early as move 6. (See recent games of Ke Jie 9p, for example.)
I agree with your larger point though. You definitely need to weigh your profit against opponent’s profit. It’s all about the balance of power. It’s ok to be surrounded if you get enough territory in return and you don’t fall too far behind in the balance of influence on the board. Of course, what is the proper balance is a skill that’s developed through experience. 
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Thanks, Mark!
Funny that you advise that, because 3-3 invasions are the new black [quote=“BradleyKH, post:1, topic:13405”]
does the territory-influence balance determine when it’s OK or not OK to get surrounded?
[/quote]
As @Kreur said, context is everything, and there is no easy answer to your question. What you say is correct, but there are other considerations. A very important one is sente (initiative). For example a usual approach for Alphago is to take territory in sente, then move to the outside to counter the opponent’s influence.
An awesome video If you’d like to learn more (warning: advanced level):
That’s clearly the case - for some players.
So then you also have to consider who is asking the question, and what can they do with the answer.
I can tell you from personal pain: I can’t invade 3-3 early and get away with it. I literally had that same thought in my head in two games in succession “Oh, 3-3 early is actually OK” and it totally wasn’t OK.
So for a TPK or early DDK, I reckon the old advice is still good. Maybe if you are a Dan or AlphaGo you know how to deal with the influence you gave away, but for sure in both cases for me it killed me dead.
There’s a much broader topic here that fascinates me, also. It’s that there appears to have emerged a whole new layer of play, even more stratifying “who can play what style”.
We already all sort of know that DDKs can’t play like Dans, and from time to time you hear “Oh, that’s Dan stuff, we can’t hope to understand that”. I think I’ve seen SDK’s say that in chat. But of course aspiring Dans work on that and get taught about it by Dans. And of course from time to time SDKs and DDKs look at those lessons and see if they can glean something.
Now there is a whole another level. It is AlphaGo teaching Dans how to be Alphas. I’ve seen the Dan’s struggling and progressing with this (there is a classic Nick Sibicky video where he’s kind of devastated by it!, and another Dwyrin one showing a Pro going all Alphago and mysterious, and making it work). And SDKs probably can look up and glean stuff. But it is so far from DDK (let alone TPK) that the things that are going on just don’t apply downwards, and I really think there will be absolute facts - totally solid wisdom - at the lower level that are totally wrong at the upper level, to the extent where us lower level people have to really recognise that, and the upper level teachers do too.
This is why, by the way, I think Nick didn’t have to despair, and hopefully he has recovered. I was struck by him saying really sadly and earnestly “well, it appears everything I have taught you is wrong”. But that isn’t true. All his teaching are great for DDKs and solidifying SDKs. He just now has a new task of adding a new layer of learning, and being able to keep them separated, or at least identify how and what flows down.
Whoa, sorry for the long typing - it’s fascinating
GaJ
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Okay, so here is my basic rule for invading the 3-3.
If your opponent already has a moyo surrounding his/her 4-4 stone, then you can invade.
If your opponent has no chance of a moyo around the 4-4, then you can invade. Ex: having a wall facing that way.
If your opponent has a potential moyo around that area, then it is not okay to invade. In most circumstances, this is the case.
Note that this doesn’t apply to every scenario, and as several of you stated above, some players can deal with the influence. So these rules really only help some people, but I hope it helps you
-MrC
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Actually, I think the modern theory (post AlphaGo) is almost the opposite of that.
If your opponent already has a moyo around the 4-4 point (e.g. two extensions) then it’s usually not OK to invade 3-3 as it will only strengthen the moyo and turn it into more or less territory. You should instead aim at approaching the 4-4 to start a fight in their moyo to destroy it. If the moyo is so strong/thick/tight that starting a fight is an overplay or if playing 3-3 invasion makes him overconcentrated, then of course 3-3 may be the correct move, but even then you should usually first reduce the moyo from the outside before invading the 3-3, if possible.
Early 3-3 invasion against an isolated 4-4 however is perfectly OK. There’s usually three things that can happen, either your opponent takes sente to play an extension from his wall, in which case the corner result is locally OK for you and you don’t really get sealed in. Otherwise your opponent might give you sente, in which case you can use it to reduce the potential your opponent got on the outside. Third way your opponent might play is to do the double have and give you a ponnuki in sente instead of sealing you in the corned, but in the early stages of the game, a sente ponnuki is usually worth more than the solid corner territory your opponent gets.
More generally speaking, getting sealed in in the opening is usually OK if one of the following holds true:
- You already have stones in place on the outside that reduce the potential your opponent gets
- You get sente and can use it to reduce your opponents potential
- Your opponent is already so thick in that general area that the extra thickness he gets from sealing you in ends up just being overconcentrated.
I guess there’s also a fourth scenario where getting sealed in is OK, which is when the territory you get is simply too big for the thickness to be enough of a compensation. Often happens when your opponent starts with 5-5 points or something like that.
Also, always keep in mind the difference of stones each player has played in that general area. Remember that any normal big opening stone is worth something like 14 points, so if after the invasion it looks like your opponent has maybe 40 points more worth of stuff than you but you have ended up playing three stones less in that area, the result is probably good for you.
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