As Tooveli has already suggested, letting black live easily on the right side is good for black. Following that logic, I consider an approach from above to be forced:
- Click Here To Show Diagram Code
[go]$$Bcm17 White's next move
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . X , X . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . 1 . . |
$$ | . . . O . X . . . , . . . . . , . . . |
$$ | . . O X X . . . . X . O . . . . O . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
But then the question naturally arises: if white's move is this good and this obvious, why would black play

there in the first place? Surely, as a pro, he can see

coming.
And he can see what it looks like if he runs:
- Click Here To Show Diagram Code
[go]$$Bcm17 A bad sequence for black
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . X , X . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . 5 . 3 . 1 . . |
$$ | . . . O . X . . . , 6 . . . . , . . . |
$$ | . . O X X . . . . X . O . . 4 . O . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
If he attaches as Chew inquired about, white just slides under to connect M3.
- Click Here To Show Diagram Code
[go]$$Bcm17 Another bad sequence for black
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . X , X . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . 1 . . |
$$ | . . . O . X . . . , . . . . . , . . . |
$$ | . . O X X . . . . X . O . 7 5 3 O . . |
$$ | . . O . . . . . . . . . . 8 6 4 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
All of these look better for white. So what is black up to?
My anwer to this is derived by a long and twisted route. It starts with an observation by Topazg and maybe others that black has a weak spot:
- Click Here To Show Diagram Code
[go]$$W
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . O . X . . . , . . . . . , . . . |
$$ | . . O X X . . W . X . O . . . . O . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Black has several obvious ways to fix this. None of them look good.
This is too slow and over concentrated:
- Click Here To Show Diagram Code
[go]$$W
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . O . X . . . , . . . . . , . . . |
$$ | . . O X X . . B . X . O . . . . O . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
This encourages the parallel response from white, and white gets more from the exchange than black:
- Click Here To Show Diagram Code
[go]$$B
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . 1 . 2 . . . . . . . |
$$ | . . . O . X . . . , . . . . . , . . . |
$$ | . . O X X . . . . X . O . . . . O . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Black would like to have this problem go away without resorting to slack moves like the two above. The best solution that I can see is to keep white's M3 stone weak - or even kill it.
Black would like to do something like this:
- Click Here To Show Diagram Code
[go]$$B P3 may be just as good
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . O . X . . . , . . . . . , . . . |
$$ | . . O X X . . . . X . O . 1 . . O . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
But that just leads to this, and black has to take a move to defend his lower left group, and it ends up looking good for white:
- Click Here To Show Diagram Code
[go]$$B I'm not certain about exactly where 4 goes
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . 3 . 2 . . . . . . . |
$$ | . . . O . X . . . , . . . . 4 , . . . |
$$ | . . O X X . . . . X . O . 1 . . O . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
So I've been pondering sequences like those above, noting that black would like to play something like O3 or P3 without the natural white response at M5 being available. Then I see black make a move that makes no sense by itself.
My conclusion is that black's R5 is a sacrifice, and that he is going to make a double attack on the corner like this:
- Click Here To Show Diagram Code
[go]$$Bcm17
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . X , X . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . 1 . . |
$$ | . . . O . X . . . , . . . . . , . . . |
$$ | . . O X X . . . . X . O . . 3 . O . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
...or this:
- Click Here To Show Diagram Code
[go]$$Bcm17
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . X , X . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . 1 . . |
$$ | . . . O . X . . . , . . . . . , . . . |
$$ | . . O X X . . . . X . O . 3 . . O . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
...or this:
- Click Here To Show Diagram Code
[go]$$Bcm17
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . X , X . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . 1 . . |
$$ | . . . O . X . . . , . . . 3 . , . . . |
$$ | . . O X X . . . . X . O . . . . O . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
One of the things that I am not sure about is how easy is it to attack a 3-3 stone, even with two approach moves?
The following are speculations:
- Click Here To Show Diagram Code
[go]$$Wm20
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . 1 . . . 8 X . . |
$$ | . . . O . X . . . , . . . . . 7 5 6 . |
$$ | . . O X X . . . . X . O . . X . O 4 . |
$$ | . . O . . . . . . . . . . . . . 3 2 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
- Click Here To Show Diagram Code
[go]$$Wm20
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . 1 . . . . X . . |
$$ | . . . O . X . . . , . . . . 7 , 5 6 . |
$$ | . . O X X . . . . X . O . X . . O 4 . |
$$ | . . O . . . . . . . . . . . . . 3 2 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]