Unless I've misunderstood you only explain why 1 is good (which I agree with assuming 2 isn't answered at the top). Why don't you think the following is better for Black? I can't see the value of L18.

Click Here To Show Diagram Code

[go]$$Bcm1 Prisoners:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . 2 . . O O X . |
$$ | . . X , O . . O . X . X . . O , X . . |
$$ | . X . . . . . O X . . . . . . . . X . |
$$ | . . . X . . . . X . . O . . O . . . . |
$$ | . . . . X . O . . . . . . . . X . . . |
$$ | . . O . . . . . X . . 1 . O . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . O . . . . . , . . O . O X X . . |
$$ | . . . . . 3 . . . . . . . O X . . . . |
$$ | . . . . . . . . . . . . . a X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

i dont see anything black can do to hurt me now.
but i just misread L&D of another game in ogs.
it is simple but i read it wrong and i thought my opponent was misreading...
maybe i misread below??

Click Here To Show Diagram Code

[go]$$Bcm41 Prisoners:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . X . . 4 X . . . . |
$$ | . X O O . . . . . . . . O . . O O X . |
$$ | . . X , O . . O . X . X . . O , X . . |
$$ | . X . . . . . O X . . . . . . . . X . |
$$ | . . . X . . . . X . . O . . O . . . . |
$$ | . . . . X . O . . . . . . . . X . . . |
$$ | . . O . . . . . X . . X . O . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . O . . . . . , . . O . O X X . . |
$$ | . . . . . O . . . . . . . O X . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

I feel it's a matter of keeping those two groups split and maintaining all aji. They're 2/3 alive, but I'd hate to miss an attack if the situation in the center changes. His move to go in between gives him good followups later, so White will have to keep an eye out and make sure his center doesn't get sealed off.

Your move might be a possibility.

Unless he makes a big mistake, my intent isn't to kill this group. Instead, I just want a piece of it, enough that it compensates for letting him move elsewhere twice.

How much of the group is enough?

i think i m ahead even without komi
Top groups are are alive. My tail is light so i can tenuki.
I dont think he has time to capture my tail.
if he does he will lose more points

This is what I meant by taking a piece of it; hopefully that answers your question jts .

If white did not have sente, I would think black was winning. Where will W play?

Click Here To Show Diagram Code

[go]$$Bcm51 Prisoners: white 2 black 0
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . . . . . . . . X . . O . O . . . |
$$ | . X O O . . . . . . . . O O . O O X . |
$$ | . . X , O . . O . X . X . . O X X . . |
$$ | . X . . . . . O X . . . . 1 X . . X . |
$$ | . . . X . . . . X . . O . . O . . . . |
$$ | . . . . X . O . . . . . . . . X . . . |
$$ | . . O . . . . . X . . X . O . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . O . . . . . . . . . c . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . a . . . . . . . . . . . O . . . . |
$$ | . . . O . . . . . b . . O . O X X . . |
$$ | . . . . . O . . . . . . . O X . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

I do feel like white should play quite actively. C possible?

Click Here To Show Diagram Code

[go]$$Bcm51 Prisoners: white 2 black 0
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . . . . . . . . X . . O . O . . . |
$$ | . X O O . . . . . . . . O O . O O X . |
$$ | . . X , O . . O . X . X . . O X X . . |
$$ | . X . . . . . O X . . . . 1 X . . X . |
$$ | . . . X . . . . X . . O . . O . . . . |
$$ | . . . . X . O . . . . . . . . X . . . |
$$ | . . O . . . . . X . . X . O . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . O . . . . . . . . . c . g . . . |
$$ | . . . . . . . . . . . . . . d h . . . |
$$ | . . . . . . . . . . . . . . . e . . . |
$$ | . . . . . . . . . . . . . . . . f . . |
$$ | . . a . . . . . . . . . . . O . . . . |
$$ | . . . O . . . . . b . . O . O X X . . |
$$ | . . . . . O . . . . . . . O X . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

My intuitions.

a is clearly huge but seems smaller than the right side to me where Black has the opportunity to create a lot of points and threaten to capture the White group on a large scale (starting at something like e). This seems Black's best way to catch up so White needs to play on the right. (I think White is ahead by the amount of points that the influence in the lower right is worth)

b still seems wrong. The bottom is undercut and we shouldn't be trying to make points from the White lower-right group anyway.

c is the move that jumps out but it might be too close to the sacrifice group that Black can still manage to take the right side and threaten a large capture (with g or h or something nearby). If Black manages to take the right side in sente and then come in to the bottom left then this seems like a failure for White.

d was my next thought as this appears to break up the right hand side and prevents a large scale capture by Black but it has a slightly ugly feeling. It feels like it is in the correct area of the board but the shape it makes with the lower right group and with the potential moyo doesn't feel quite right.

f seems like a natural continuation for the White group but if Black answers with h then maybe he is getting a large enough potential capture.

h seems to be a key point for Black in securing the side but it has an even bigger ugliness factor than d (for White). This almost brings us back to playing a but I still think that would give Black control of the game and therefore a chance to get back in it.

There are other moves around d to consider but they would com from reading.

Basically, I've no idea where to play. I think I said in a previous post that I never know how to use groups like the White one in the lower right properly. I'm prepared to be surprised.

my initial thought was below..
i didnt want any complication of him split my group into two..
but...after some thought...above probe is a perfect timing since he decided to capture my tail.
it is asking him how badly do you want my group???

Click Here To Show Diagram Code

[go]$$Bcm51 Prisoners: white 2 black 0
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . . . . . . . . X . . O . O . . . |
$$ | . X O O . . . . . . . . O O . O O X . |
$$ | . . X , O . . O . X . X . . O X X . . |
$$ | . X . . . . . O X . . . . 1 X . . X . |
$$ | . . . X . . . . X . . O . . O . . . . |
$$ | . . . . X . O . . . . . . . . X . . . |
$$ | . . O . . . . . X . . X . O . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . O . . . . . 2 . . O . O X X . . |
$$ | . . . . . O . . . . . . . O X . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

he can capture my group with a or b... personally i would hate to capture them as he did and select c.
but since he spent a move to capture...it is better not capturing move prior.
twari analysis will say he made a mistake either way..

Click Here To Show Diagram Code

[go]$$Bcm51 Prisoners: white 2 black 0
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . . . . . . . . X . . O . O . . . |
$$ | . X O O . . . . . . . . O O . O O X . |
$$ | . . X , O . . O . X . X . . O X X . . |
$$ | . X . . . . . O X . . . . 1 X . . X . |
$$ | . . . X . . . . X . . O . . O . . . . |
$$ | . . . . X . O . . . . . . . . X . . . |
$$ | . . O . . . . . X . . X a O . X . . . |
$$ | . . . . . . . . . . . 2 b . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . O . . . . . , . . O . O X X . . |
$$ | . . . . . O . . . . . c . O X . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Heh I am surprised. (Twice!)

Yeah

In hindsight, we didn't consider any contact plays on the slightly fluffy group of stones that after were no longer weak anyway.

It does - I like explanations that start "Behold!", so thank you - but what wasn't so clear is whether to be satisfied you need to count these three stones as captured (such that W's trying to pull them out would be throwing good money after bad), or whether you are thinking of your secure profit here as just the M14 area, with the main accomplishment being to gain control over the center and security for your top group.

Or, if that question doesn't make sense: in a game, if I had the chance to play , I would have no idea what I had accomplished. Is it basically a big yose move, or does it radically change the strength and weakness of the surrounding groups and/or the balance of territory? Do the white stones still have tons of aji to cause trouble on either side, or are they just dead weight?

I'm a lowly DDK, so I _naturally_ have no clue what is going on. Who's winning? All in all, I think that these two are playing a very interesting game.

IMHO, 'a' and 'b' are the wrong direction, and c is premature. I'd play like this:

Click Here To Show Diagram Code

[go]$$c
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . . . . . . . . X . . O . O . . . |
$$ | . X O O . . . . . . . . O O . O O X . |
$$ | . . X , O . . O . X . X . . O X X . . |
$$ | . X . . . . . O X . . . . 1 X . . X . |
$$ | . . . X . . . . X . . O . . O . . . . |
$$ | . . . . X . O . . . . . . . . X . . . |
$$ | . . O . . . . . X . . X . O . X . . . |
$$ | . . . . . . . . . . 3 2 . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . O . . . . . , . . O . O X X . . |
$$ | . . . . . O . . . . . . . O X . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

As I see it, the board is like this:

All black's points are on the right
White's leftern moyo is one move away from being very big
Black has no weak group
Responding contact here does seem painful (slow) for black

Honestly, this situation is a bit above me. I'd throw a stone at C7 and just kind of hope.

I agree with Joaz 'c' area seems too early and also a bit awkward to play without a Q6-ish stone. Actually. I change my vote to black Q7.

Why is he so adamant about playing in this area straight away? Regardless, I still have to play the strongest response. To play one space up is too slack, but to tenuki elsewhere also seems slack as well.

It leaves a lot of big endgame potential mostly, so that's the main reasoning behind 51. I'd say it's 75% endgame value, 25% stability of the center group.