Here's a position from a game I (white) am playing on OGS (It's endgame now and I'm comfortably ahead so we can discuss the opening). My opponent invaded at the marked point and I couldn't find a good answer so played tenuki. Stated like that it seems fairly sensible ("if you don't know what to do, tenuki"), but for me to tenuki an invasion like that felt rather strange as it allows black to separate my positions. However, I didn't like the results of me playing what felt like the most natural move of attach on top (
a) to connect as then black will live with points inside my moyo and I get a wall that didn't seem useful with his strong ponnuki group on the left. (h5 instead of h4 is similar idea, and by not contacting black tries to not give him momentum to settle, but seemed similarly bad). He might even live in sente. I didn't mind my groups getting cut that much as the corner group to the left is alive (and I didn't want to lose the corner points I had invested in (yeah I know they aren't 100% my points yet)) and although the one to the right could get a bit weak it can play moves like n6 to help it which also have aims at black's right side. So I played the big move at
b which developed my top moyo and reduced the potential of his left side thickness. I had in fact expected black to approach here instead of invading (and was planning to attach and crosscut if he hanes to try to overconcentrate him on the left and solidify my corner and top side) as I wasn't planning on spending a move to fix that invasion point any time soon. So my thinking was that black's invasion was perhaps too early, and my tenuki was a good answer, although it felt a bit strange. What do you think?
$$cm23 How to answer this invasion, or not?
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . O . . . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . b . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . . . . X . . . |
$$ | . X O . . . . . . . . . . . . . . . . |
$$ | . O X . . . . . . . . . . . . . . . . |
$$ | . O X . X . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . O . O . a . O . . O . X , . . . |
$$ | . . . . . . . 1 . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
- Click Here To Show Diagram Code
[go]$$cm23 How to answer this invasion, or not?
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . O . . . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . b . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . . . . X . . . |
$$ | . X O . . . . . . . . . . . . . . . . |
$$ | . O X . . . . . . . . . . . . . . . . |
$$ | . O X . X . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . O . O . a . O . . O . X , . . . |
$$ | . . . . . . . 1 . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Here's how the game continued. Black cut my groups and lived in gote, whilst I kept the corner and got the n6 jump.
$$Wcm24 Moves 24 to 33
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . O . . . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . . . . X . . . |
$$ | . X O 4 . . . . . . . . . . . . . . . |
$$ | . O X . 3 . . . . . . . . . . . . . . |
$$ | . O X . X 5 . . 6 . . . 7 . . . . . . |
$$ | . . O . . . . 2 . . . . . . . . . . . |
$$ | . . . O 9 O . . . O . . O . X , . . . |
$$ | . . . . 8 . . X . . . . . . . X . . . |
$$ | . . . . . 0 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
- Click Here To Show Diagram Code
[go]$$Wcm24 Moves 24 to 33
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . O . . . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . . . . X . . . |
$$ | . X O 4 . . . . . . . . . . . . . . . |
$$ | . O X . 3 . . . . . . . . . . . . . . |
$$ | . O X . X 5 . . 6 . . . 7 . . . . . . |
$$ | . . O . . . . 2 . . . . . . . . . . . |
$$ | . . . O 9 O . . . O . . O . X , . . . |
$$ | . . . . 8 . . X . . . . . . . X . . . |
$$ | . . . . . 0 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
$$Wcm34 Moves 34 to 43
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . O . . . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . . . . X . . . |
$$ | . X . X . . . . . . . . . . . . . . . |
$$ | . O X . O . . . . . . . . . . . . . . |
$$ | . O X . X O . . X . . . O . . . . . . |
$$ | . . O . . . . X . . . . . . . . . . . |
$$ | . . . O O O . 2 1 O . . O . X , . . . |
$$ | . . . . X . . X 6 7 . . . . . X . . . |
$$ | . . . 5 . X . 4 3 8 9 . . . . . . . . |
$$ | . . . . . . . . 0 . . . . . . . . . . |
$$ ---------------------------------------
- Click Here To Show Diagram Code
[go]$$Wcm34 Moves 34 to 43
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . O . . . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . . . . X . . . |
$$ | . X . X . . . . . . . . . . . . . . . |
$$ | . O X . O . . . . . . . . . . . . . . |
$$ | . O X . X O . . X . . . O . . . . . . |
$$ | . . O . . . . X . . . . . . . . . . . |
$$ | . . . O O O . 2 1 O . . O . X , . . . |
$$ | . . . . X . . X 6 7 . . . . . X . . . |
$$ | . . . 5 . X . 4 3 8 9 . . . . . . . . |
$$ | . . . . . . . . 0 . . . . . . . . . . |
$$ ---------------------------------------[/go]
We could just leave the discussion there, but I think to judge the result you really need to carry on. Something I thought about here was his exchange of j6 for n6 probably turned out to be bad given that he ended up living in gote on the side anyway. Before that I had been somewhat afraid of the m5 peep (though that weakens his right side, so perhaps only do that as kikashi before defending with q6 or q7) and then crude but perhaps effective m4 push and cut; my p4 p2 combo was aimed at giving ways to deal with that.
I now had sente for another tenuki. Closing the corner at e17 was one idea, but I thought the lower area was more urgent as my n6 jump aimed at invading the right. If I played e17 black would probably defend the lower right area which would simultaneously put some pressure on my n6 group which wasn't actually settled yet. If I invade the right immediately it poses black a difficult question: does he separate my invasion from n6 which would mean it could live comfortably on the right side and he loses a lot of points there for an attack of questionable value on my n6 group, or does he keep some of his side points but let me connect my groups which also nicely settles them? He chose the later.
$$Wcm44 Moves 44 to 53
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . O . . . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . . . . X . . . |
$$ | . X . X . . . . . . . . . . . . 8 4 . |
$$ | . O X . O . . . . . . . . . . . 3 7 . |
$$ | . O X . X O . . X . . . O . . . . . . |
$$ | . . O . . . . X . . . . . . . . . 9 . |
$$ | . . . O O O . X O O . . O . X , 1 . . |
$$ | . . . . X . . X X O . . . . . X 2 5 0 |
$$ | . . . O . X . X . X O . . . . . . 6 . |
$$ | . . . . . . . . X . . . . . . . . . . |
$$ ---------------------------------------
- Click Here To Show Diagram Code
[go]$$Wcm44 Moves 44 to 53
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . O . . . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . . . . X . . . |
$$ | . X . X . . . . . . . . . . . . 8 4 . |
$$ | . O X . O . . . . . . . . . . . 3 7 . |
$$ | . O X . X O . . X . . . O . . . . . . |
$$ | . . O . . . . X . . . . . . . . . 9 . |
$$ | . . . O O O . X O O . . O . X , 1 . . |
$$ | . . . . X . . X X O . . . . . X 2 5 0 |
$$ | . . . O . X . X . X O . . . . . . 6 . |
$$ | . . . . . . . . X . . . . . . . . . . |
$$ ---------------------------------------[/go]
(The alternating of moves between r4 area and r7 area was rather amusing and might seem like I am changing my mind about what to do, but it seemed like the correct technique to me).
$$Wcm54 Moves 54 to 63
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . O . . . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . . . 6 X . . . |
$$ | . X . X . . . . . . . . 9 2 5 . X X . |
$$ | . O X . O . . . . . . . . 0 1 . O O . |
$$ | . O X . X O . . X . . . O . . . . . . |
$$ | . . O . . . . X . . . . . . . . . O . |
$$ | . . . O O O . X O O . . O . X , O 4 3 |
$$ | . . . . X . . X X O . . . . . X X 7 X |
$$ | . . . O . X . X . X O . . . . . . X 8 |
$$ | . . . . . . . . X . . . . . . . . . . |
$$ ---------------------------------------
- Click Here To Show Diagram Code
[go]$$Wcm54 Moves 54 to 63
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . O . . . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . . . 6 X . . . |
$$ | . X . X . . . . . . . . 9 2 5 . X X . |
$$ | . O X . O . . . . . . . . 0 1 . O O . |
$$ | . O X . X O . . X . . . O . . . . . . |
$$ | . . O . . . . X . . . . . . . . . O . |
$$ | . . . O O O . X O O . . O . X , O 4 3 |
$$ | . . . . X . . X X O . . . . . X X 7 X |
$$ | . . . O . X . X . X O . . . . . . X 8 |
$$ | . . . . . . . . X . . . . . . . . . . |
$$ ---------------------------------------[/go]
(Btw I think black's 63 and 65 were mistakes as they meant I could easily take sente)
$$W Moves 64 to 70
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . O . . . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . 7 . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . 2 4 X X . . . |
$$ | . X . X . . . . . . . . O X O . X X . |
$$ | . O X . O . . . . . . . 3 X O . O O . |
$$ | . O X . X O . . X . . . O 1 . . . . . |
$$ | . . O . . . . X . . . . . . . . . O . |
$$ | . . . O O O . X O O . . O . X , O . O |
$$ | . . . . X . . X X O . . . . . X X O X |
$$ | . . . O . X . X . X O . . . 5 6 . X X |
$$ | . . . . . . . . X . . . . . . . . . . |
$$ ---------------------------------------
- Click Here To Show Diagram Code
[go]$$W Moves 64 to 70
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . O . . . . . O . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . 7 . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . 2 4 X X . . . |
$$ | . X . X . . . . . . . . O X O . X X . |
$$ | . O X . O . . . . . . . 3 X O . O O . |
$$ | . O X . X O . . X . . . O 1 . . . . . |
$$ | . . O . . . . X . . . . . . . . . O . |
$$ | . . . O O O . X O O . . O . X , O . O |
$$ | . . . . X . . X X O . . . . . X X O X |
$$ | . . . O . X . X . X O . . . 5 6 . X X |
$$ | . . . . . . . . X . . . . . . . . . . |
$$ ---------------------------------------[/go]
So in the end I had reduced black's lower right corner down to 4 points and settled my n6 group for now by shoving through his side. In exchange he got a wall to grow his upper right side (r12 invasion nigh on impossible now) and centre, but I had sente to reduce it at n14. I felt this development went smoothly for me.
Here's the full game so far:
So, what do you think of the tenuki and subsequent strategy based on it?