Well, was kind of hoping he would reinforce that group with something like Q10 in gote, unfortunately he has chosen a way that is likely to end with his sente (but gives me a lot of territory and a rock solid group in exchange, so it's fine I think). Also by choosing this violent way of settling, he will gain a lot of strength but only locally, the huge gap is still there and he still needs to play around Q10 to be really safe.
I briefly considered replying at R5, but I don't think it would be a good idea, I also considered Q13 to gain sente, but I can't bring myself to just give up the corner so easily (also he might just tenuki anyway).
Now I'm not really happy with my last move, I'm sure there was something better and I feel like I lost a chance.
I promised some reasoning yesterday, here it is:
$$c Prisoners: B=0, W=0
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . X . X X O . . . |
$$ | . . . O . . . . . , . . . . O , O . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . e . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , C . . |
$$ | . . . . . . . . . . . . . . . . C . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . c . . |
$$ | . . . , . . . . . d . . . . . O . . . |
$$ | . . . X . . . . . . . . a b . . . . . |
$$ | . . . f . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
- Click Here To Show Diagram Code
[go]$$c Prisoners: B=0, W=0
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . X . X X O . . . |
$$ | . . . O . . . . . , . . . . O , O . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . e . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , C . . |
$$ | . . . . . . . . . . . . . . . . C . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . c . . |
$$ | . . . , . . . . . d . . . . . O . . . |
$$ | . . . X . . . . . . . . a b . . . . . |
$$ | . . . f . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
As you can see I was pretty undecided!
Clear points of interest are the lower right corner (because a black play at A is kind of a double kakari and works great with his shimari on the other side) and the big gap marked with circles (which means that black must be careful of white getting too strong there, but also makes the two stones on the side quite light)
My local options in the corner are mainly A, B, and C. If C was actually sente it would for sure be the best move, but I don't really think c is very sente, because black can easily treat R7 lightly, approach on or around B anyway, forcing white to defend the corner, and then defend at Q10. After this if white attacks the approach stone on the left, B can sacrifice it and build towards his shimari.
$$Wc Prisoners: B=0, W=0
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . X . X X O . . . |
$$ | . . . O . . . . . , . . . . O , O . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . 4 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . 8 . 7 . 9 . . . 1 . . |
$$ | . . . , . . . . . . . . . . . O . . . |
$$ | . . . X . . . . 6 . 5 . 2 . 3 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------
- Click Here To Show Diagram Code
[go]$$Wc Prisoners: B=0, W=0
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . X . X X O . . . |
$$ | . . . O . . . . . , . . . . O , O . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . 4 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . 8 . 7 . 9 . . . 1 . . |
$$ | . . . , . . . . . . . . . . . O . . . |
$$ | . . . X . . . . 6 . 5 . 2 . 3 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
something like this is not bad for B I think.
If we exclude C, that leaves A and B, it's mostly the same, the main difference is that with A black can still invade at the 3-3 and live easily, with B it's Ko I think. But anyway black can't do it now because that would really hurt his stones on the right.
So probably A is better because it's larger and extends more in the direction black should have wanted to play, therefore reducing the value of the shimari.
Discounting the bottom right corner, there are other points I'd like to play. D is kind of similar to A, but favours the side and reducing black prospects more than building territory in the corner. Looks kind of vague and wishy washy, but on the other hand using 4-4 for territory is supposed to be wrong.
E is also a very big point for the same reasons as A (black approaches and builds towards his shimari). but I guess A is bigger because it's more severe being a double kakari and all.
Last choice is f, since I am really undecided, this looks like a good time for a probe. I don't really understand black's general plan and what he wants. As I said before I think R7 was a move in the wrong direction and does not make a lot of sense to me, maybe the probe would help shed some light on the matter. But then I can still probe whenever I want to. And maybe it won't be necessary at all, especially since playing A already reduces the potential on the bottom
So A it is!
. It does look better, particularly because it kicks black's hoshi in the teeth.
then white can capture P17 whenever he wants, getting a _huge_ corner and later a strong attack on the top. So really, P16 attacks two groups at the same time, it feels hard to just let this chance go by.