It's complex.
I can reject MW's sequence
- Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . X . . . . . X . . . . . . . |
$$ | . . . O . O X . . , . . . . . , . . . |
$$ | . . . . . O X . . . . . . . . . X . . |
$$ | . . . . . X X O X . . . . . . . . . . |
$$ | . . O O . . . O X . X . . . . . . . . |
$$ | . . . . . X . O 6 . . . X . . . . . . |
$$ | . . X . . . X 4 O 9 O O X . . O . . . |
$$ | . . . , X X O O 5 O 8 X O O . , . . . |
$$ | . . . . X O O 7 O X X . X O . O . . . |
$$ | . . . . O X 2 3 X . . . . X X 0 . . . |
$$ | . . . O . X 1 X X . X a X . . . . . . |
$$ | . . O . O . O . O . O O . . . . . . . |
$$ | . . . X O . O . . . . . . O . . . . . |
$$ | . . O O X X . . O , X . . . . , . . . |
$$ | . . O X . X . . . . . . . . X . . . . |
$$ | . . X . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
4 above isn't totally daft. I could fight the ko after W connects at 5, or I could cut off a chunk of group as shown. W captures 3 stones, But my attack on the remaining group isn't too fierce, although my centre stones are reasonably strong. (There's some aji and W can aim at a ko after a, for example, but it's not an immediate concern.) this line may be playable for B.
Or I can accept MW's line.
- Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . X . . . . . X . . . . . . . |
$$ | . . . O . O X . . , . . . . . , . . . |
$$ | . . . . . O X . . . . . . . . . X . . |
$$ | . . . . . X X O X . . . . . . . . . . |
$$ | . . O O . . . O X . X . . . . . . . . |
$$ | . . . . . X . O . . . . X . . . . . . |
$$ | . . X . . . X 4 O . O O X . . O . . . |
$$ | . . . , X X O O 2 O 5 X O O . , . . . |
$$ | . . . . X O O X O X X 3 X O . O . . . |
$$ | . . . . O X X . X . . 1 . X X . . . . |
$$ | . . . O . X O X X . X a X . . . . . . |
$$ | . . O . O . O b O . O O . . . . . . . |
$$ | . . . X O . O . . . . . . O . 6 . . . |
$$ | . . O O X X . . O , X . . . . , . . . |
$$ | . . O X . X . . . . . . . . X . . . . |
$$ | . . X . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Caputring at 2 is an obvious thing to do. Following this, Mw has a couple of choices. He can save a small chunk of centre, and connect, as shown.
I then have different choice. a looksuseful, as it connect solidly, separates W and aims at a later attack, and possibly cut at b. But it's very slow and may be a dame. So I may play at 6 to expand my corner and avoid a dame connection.
W will invcade the top right corner soon after this.W has very little territory in this line. A count may be:
W: 5 point lower left (the whole group may become weak so he can't get much here now.)
10-15 points RHS.
20 upper left:
Total: 40 plus komi.
B's is a lot more undefined.
Definite territory is :
12 point in center.
8 point lower left.
Upper side: at least 20 points. Additionally, B has what I can nab in the remaining corners.
So this looks good for B.
So W may try to avoid this, for example by:
- Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . X . . . . . X . . . . . . . |
$$ | . . . O . O X . . , . . . . . , . . . |
$$ | . . . . . O X . . . . . . . . . X . . |
$$ | . . . . . X X O X . . . . . . . . . . |
$$ | . . O O . . . O X . X . . . . . . . . |
$$ | . . . . . X . O . . . . X . . . . . . |
$$ | . . X . . . X 4 O . O O X . . O . . . |
$$ | . . . , X X O O 2 O a X O O . , . . . |
$$ | . . . . X O O X O X X 3 X O . O . . . |
$$ | . . . . O X X . X . . 1 . X X . . . . |
$$ | . . . O . X O X X . X 5 X . . . . . . |
$$ | . . O . O . O b O . O O . . . . . . . |
$$ | . . . X O . O . . . . . . O 6 . . . . |
$$ | . . O O X X . . O , X . . . . , . . . |
$$ | . . O X . X . . . . . . . . X . . . . |
$$ | . . X . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
W may choose not to save the small chunk of centre, and go for B's side stones instead. The follow up at a is big yose, but not urgent for either player. If I play this way, my initial thought is to play at 6 above and I should get a big corner. I will give up the side stones. This also seems quite playable to me.
So W may try this:
- Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . X . . . . . X . . . . . . . |
$$ | . . . O . O X . . , . . . . . , . . . |
$$ | . . . . . O X . . . . . . . . . X . . |
$$ | . . . . . X X O X . . . . . . . . . . |
$$ | . . O O . . . O X . X . . . . . . . . |
$$ | . . . . . X . O . . . . X . . . . . . |
$$ | . . X . . . X 4 O . O O X . . O . . . |
$$ | . . . , X X O O 2 O . X O O . , . . . |
$$ | . . . . X O O X O X X 6 X O . O . . . |
$$ | . . . . O X X . X . . 1 7 X X . . . . |
$$ | . . . O . X O X X . X 3 X . . . . . . |
$$ | . . O . O . O b O . O O . . . . . . . |
$$ | . . . X O . O . . . . . . O . 5 . . . |
$$ | . . O O X X . . O , X . 8 . . , a . . |
$$ | . . O X . X . . . . . . . . X . . . . |
$$ | . . X . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
In this line, W give up all the senter to get the vital point at 5. There is a question as to whether 6 genuinely is my sente or not at this time - it may be too early. I then play at 8 or a, and again seem to have a good position.
I can also consider answering the ko thereat directly e.g.:
- Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . X . . . . . X . . . . . . . |
$$ | . . . O . O X . . , . . . . . , . . . |
$$ | . . . . . O X . . . . . . . . . X . . |
$$ | . . . . . X X O X . . . . . . . . . . |
$$ | . . O O . . . O X . X . . . . . . . . |
$$ | . . . . . X . O a . . . X . . . . . . |
$$ | . . X . . . X 4 O . O O X . . O . . . |
$$ | . . . , X X O O 5 O . X O O . , . . . |
$$ | . . . . X O O X O X X . X O . O . . . |
$$ | . . . . O X X 3 X . . 1 . X X . . . . |
$$ | . . . O . X O X X . X 2 X . . . . . . |
$$ | . . O . O . O b O . O O . . . . . . . |
$$ | . . . X O . O . . . . . . O . . . . . |
$$ | . . O O X X . . O , X . . . . , . . . |
$$ | . . O X . X . . . . . . . . X . . . . |
$$ | . . X . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
I can now cut at a, almost. reverting to the very first line showed. However, it's clearly better than that line since W's ko threat haas lost points. Or I can take the ko as in the next diagram:
- Click Here To Show Diagram Code
[go]$$Bc continuation
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . X . . . . . X . . . . . . . |
$$ | . . . O . O X . . , . . . . . , . . . |
$$ | . . . . . O X . . . . . . . . . X . . |
$$ | . . . . . X X O X . . . . . . . . . . |
$$ | . . O O . . . O X . X . . . . . . . . |
$$ | . . . . . X 2 O . . . . X . . . . . . |
$$ | . . X . . 3 X X O . O O X . . O . . . |
$$ | . . . , X X O O O O . X O O . , . . . |
$$ | . . . . X O O 1 O X X . X O b O . . . |
$$ | . . . . O X X 4 X . . O . X X c . . . |
$$ | . . . O . X O X X . X X X . . . . . . |
$$ | . . O . O . O . O . O O . . . . . . . |
$$ | . . . X O . O . . . . . . O a . . . . |
$$ | . . O O X X . . O , X . . . . , . . . |
$$ | . . O X . X . . . . . . . . X . . . . |
$$ | . . X . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
W 2 may be a ko threat (it may not be. W retakes the ko. I now need a threat. a,b,c all look possible, and the position is probably quite good for B. But it's not clear cut. So I prefer the middle chunk of variations for me.