I often find it hard to know when to move a group into the center instead of settling it in the corner/on the side. "Corners, side, center" suggests running a weak-ish group to the corner first, but "don't get surrounded" could, under many circumstances, suggest otherwise.

The following position came up in a game of mine recently. I was playing black. A small fight had broken out on the right side of the board, leaving white with a heavy-ish looking group. I didn't feel totally secure about my stones in the upper right and, wanting to settle them in some way before trying to attack the white group, played Q18.

I also considered playing somewhere around O12 or N15 to move the group into the center while threatening some of white's stones. After my move at Q18, however, a white move around N14 would build the top moyo, make it easier for white to connect her groups, and would begin to surround my upper-right stones. I settled on Q18, thinking that it gives me a fair amount of points in the corner, that it threatens an invasion at M17, and that it makes my group totally strong, but now I have serious doubts about my decision.

I guess what I'm getting at is this: Are there general guidelines for when a group should jump out into the center? Should I have moved my group into the center? I felt like R11 and S11 stones negated what sort of a base I had and that if I ran to the center I would only induce white to fix her weaknesses on the top.

Thanks!

Click Here To Show Diagram Code

[go]$$c Black to Play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . O . . . . . |
$$ | . X . , . . . . . O . . . . . X . . . |
$$ | . . . O O . . . . . . . . . . . . . . |
$$ | . . X X . . . . . . . . . . . X . . . |
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . X . . . . . . . . . . . O O O . |
$$ | . . . , . . . . . , . . . . O O X X . |
$$ | . . . . . . . . . . . . . . . X O X . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . O . . O . . X . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Basics: Broken shape/Fractured shape:

Click Here To Show Diagram Code

[go]$$
$$. . . . . . . . |
$$. . . . X . . . |
$$. . . . . . . . |
$$. . . . Y . . . |
$$. . . . @ @ @ . |
$$. . . @ @ Y Y . |
$$. . . . Y O X . |
$$. . . . X . . . |
$$. . . . . . . . |[/go]

Bigger-picture strategies and ideas like when to jump out are all good and interesting,
but something very bad already happened to B's shape before this point.It is Black's shape that is a disaster, IMO, so
understanding and fixing this broken shape problem is much more important.

Click Here To Show Diagram Code

[go]$$
$$. . . . . . . . |
$$. . . . X . . . |
$$. . . . . . . . |
$$. . . . Y . . . |
$$. . . . @ @ @ . |
$$. . . @ @ Y Y . |
$$. . . . Y O X . |
$$. . . . X . . . |
$$. . . . . . . . |[/go]

Yeah, this is bad for black. But, lets look at how to deal with this now that it's here.

Click Here To Show Diagram Code

[go]$$c Black to Play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . a . . . |
$$ | . . . O . . . . . . . b . O . . . . . |
$$ | . X . , . . . . . O . . . . . X . . . |
$$ | . . . O O . . . . . . . . . . . c c . |
$$ | . . X X . . . . . . . . . . . X c c . |
$$ | . . . . . O . . . . . . . . . . c c . |
$$ | . . . . . . . . . . . . . . . X c c . |
$$ | . . . X . . . . . . . . . . . O O O . |
$$ | . . . , . . . . . , . . . . O O X X . |
$$ | . . . . . . . . . . . . . . . X O X . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . O . . O . . X . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

The move you played, "a", aims at "b", but it leaves behind plenty of room for white to gut out the side and settle himself around "c". Basically, what you want to do in a position like this is try to get that white group running.

Black is in no danger yet, you have room to live in the corner, room to run,

If white stretches too far and tries to attack it, then, like a pool that has had a stone thrown into it, you will "splash" into the surrounding positions.

Click Here To Show Diagram Code

[go]$$c Black to Play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . d O . . . f . . . c . O . . . . . |
$$ | . X . , . . . . . O . . . . . X . . . |
$$ | . . . O O . . . . . . . . . . . . . . |
$$ | . . X X e . . . . . . . . . . X . b . |
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . a X . . . |
$$ | . . . X . . . . . . . . . . . O O O . |
$$ | . . . , . . . . . , . . . . O O X X . |
$$ | . . . . . . . . . . . . . . . X O X . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . O . . O . . X . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

My gut reaction here is "a" in the above diagram, white is pretty safe, but it spoils his shape a little,

then if he tries something like "b", you enclose him, let him live, aiming at "c" immediately, (without protecting the corner)

If he then jumps into the corner, you seal him in, making sure to build good thickness and use it to disrupt his entire top side, keeping in mind the key points of d, e, and f.

It's one line of reasoning, that feels natural to me though...

_________________
Tactics yes, Tact no...

I don't want to take away from dwest's thread, but while EdLee's favorite comment is about broken shapes...

I know how this shape happened, because I just got into this situation tonight at club and the 3d said this outcome was ok for black (or at least better than what I actually played).

here's how it starts (from my 6 stone game, more or less)... white invades...

Click Here To Show Diagram Code

[go]$$c Black to Play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . X . . |
$$ | . . X . . O . . . . . . . . O O X . . |
$$ | . . . X . . . . . . . . . O . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . Y . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . @ . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . Y . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . . . X . . . O . . O . . X . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

I've probably got the order wrong, but it was about 2 hours ago, and I've already forgotten

Click Here To Show Diagram Code

[go]$$c Black to Play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . X . . |
$$ | . . X . . O . . . . . . . . O O X . . |
$$ | . . . X . . . . . . . . . O . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . Y . . . |
$$ | . . . . . . . . . . . . . . . 8 4 6 . |
$$ | . . . . . . . . . . . . . . . @ 1 5 . |
$$ | . . . . . . . . . . . . . . . 3 2 7 . |
$$ | . . . . . . . . . . . . . . . Y . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . X . . . |
$$ | . . . . . . X . . . O . . O . . X . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

But what should black do when white invades to prevent the broken shape instead?

xedover:

The attach underneath or on top is the problem, you'll automatically make them strong *somewhere*

by playing on the 4th line, white has lost most of his ability to live easily on the side, so I think either shoulder-hitting at P7 or just setting up a good attack with something like N4 is the move. Your goal should be to splash out into the surrounding positions, not to go crazy trying to connect, you're not in danger on either side and you want that group of his to stay a liability

_________________
Tactics yes, Tact no...

Actually, looking at it a bit more, I like R10, makes good shape on your upper left and basically removes all aji on the side, if he tries to stop you from connecting there, he just gets heavy.

_________________
Tactics yes, Tact no...

Another idea:

Click Here To Show Diagram Code

[go]$$c Black to Play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . X . . |
$$ | . . X . . O . . . . . . . . O O X . . |
$$ | . . . X . . . . . . . . . O . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . Y . . . |
$$ | . . . . . . . . . . . . . . 1 . . . . |
$$ | . . . . . . . . . . . . . . 2 @ . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . Y . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . 3 . X . . . |
$$ | . . . . . . X . . . O . . O . . X . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

It's not just the play on top or bottom. Maybe those are wrong in this circumstance, but they can be reasonable plays. But it's only good if you have a clear plan, because there are many weak followups that sort of look natural. Your continuation is unfortunately one of them.

Here's an analogous situation from sensei's library: http://senseis.xmp.net/?BermudaTriangle (the result is different, but the principle is roughly the same). Here's several continuations from that invasion: http://senseis.xmp.net/?FourthLineInvas ... nBothSides.

_________________
Occupy Babel!

Corners, sides, center is a proverb for setting up your stones for battle.



Better to settle them while attacking, rather than before. Besides, the group is not so weak.



P-12 is the shape move. It was shapenaji's first impulse, and mine, too. N-15 would be premature, and perhaps a bit slack in this situation.



It is not bad, but it is not sharp play.



The basic guideline is try not to just run. It is usually bad early in the game for a group to lose access to the center. Your stones are stronger than White's on the right side. S-11 was probably a mistake. You should not think of running to the center, but of attacking White. P-12 does that, as does S-13.

Here is an SGF file with my guess as to how the earlier fight on the right side went, and a few suggestions.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

You beat me to it.

Click Here To Show Diagram Code

[go]$$c Black to Play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . X . . |
$$ | . . X . . O . . . . . . . . O O X . . |
$$ | . . . X . . . . . . . . . O . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . Y . . . |
$$ | . . . . . . . . . . . . . . 1 . . . . |
$$ | . . . . . . . . . . . . . 3 2 @ . . . |
$$ | . . . . . . . . . . . . . . 4 . . . . |
$$ | . . . . . . . . . . . . . . . Y . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . 5 . X . . . |
$$ | . . . . . . X . . . O . . O . . X . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

But this is the sequence I envisioned.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Ah, yes, playing the hane first is much better

I'd just like to thank you all for the thoughtful replies. I lurk around this forum a lot. In the few instances when I've posted questions, I've always been amazed at the helpfulness of this community. You guys are great!

xed_over,