That connection under in the top left is screaming to me. As soon as black connects, white is in for a horrible time, as his topmost group is heavy and eyeless. Black, too, would cry if it were denied him.

White's already got no eyes in that corner, and the connection is gote. I think Black would be a bit sad to make that connection unless it turned out necessary for his left group. Not being sealed in and aiming for a way to profit on the top whilst making White keep running feels superior if Black can find a sequence to do it.

White can prevent the connection in sente by exchanging b18 for b19; a common technique.

So, what's the threat if Black does not respond with B19? In other words, why is b18 sente?

Click Here To Show Diagram Code

[go]$$Wc
$$ ---------------------------------------
$$ | . a . . . . . . . . . . . . . . . . . |
$$ | . 1 X . X . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . O , . . X X . , . . . . . X . . . |
$$ | . X O O O O O . . . . . . . . . . . . |
$$ | . X . . X . . . O . . . . . . . . . . |
$$ | . . X . . . O . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . O X X X X . . . . . . . . . . . . |
$$ | . . . O X O . . . , . . . . . , . . . |
$$ | . . O . O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . , . . . |
$$ | . . . X . . . . . . . . . . . O . . . |
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Incidentally, Black has enough space to make two eyes, if I'm not mistaken.

Click Here To Show Diagram Code

[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . X . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . 1 O , . . X X . , . . . . . X . . . |
$$ | 9 X O O O O O . . . . . . . . . . . . |
$$ | . X 6 7 X . . . O . . . . . . . . . . |
$$ | 4 . X 8 . 0 O . . . . . . . . . . . . |
$$ | . 2 5 X . . . . . . . . . . . . . . . |
$$ | . 3 O X X X X . . . . . . . . . . . . |
$$ | . . . O X O . . . , . . . . . , . . . |
$$ | . . O . O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . , . . . |
$$ | . . . X . . . . . . . . . . . O . . . |
$$ | . . X O O . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

It's not 100% sente, but the followup is c19 atari which is very big for increasing white eyespace in corner and reducing the black group's eyespace too. If that is ignored then white can aim at things like k16/k17 to attack the whole black group on the top side.

I've changed my mind, the aji left by the descend has been annoying me and Tom loves aji to mess around with.

What's your plan if Tom connects under?

Connection underneath seems like endgame. If Padraig prevents the connection under then I get another move somewhere else. Also if I connect underneath then my stones have no base and are eyeless, and G2 or G3 would be a nice attack on them

I don't really have one other than trying to get this group out into the centre and not sealed in or at least create some potential eyespace on the outside. I haven't faced this particular sequence many times so I'm still very unused to it.

I apologise for the lack of comments but my hands are quite stiff and shaky from the lithium making typing awkward. I don't want to let him enclose this corner, I'd like a position on the right side, or if he pincers a group on the bottom to harass his new weak group with. I'm probably missing an important sente move that makes a nice few points but I can't see it. Letting him get a shimari at the back of his weak group would be too nice for him. He'd too easily be able to build on the left now that my corner has some problems.

Approaching the corner is certainly what I was looking at, though I thought black could make the high one space approach and come out fine. Pincering is not good for white because of the weak group on the bottom left and the black hoshi stone at the top right, I feel.

The plan is to induce a move on the bottom and then attack from the top. May end badly but should be fun!