I'm not sure if I should post this to the Study journal, but this seems more appropriate.

I'm going through this game (first 50 moves, for now), at the Hoensha:



...and move 16 is the first one that puzzles me. This is a game between an excommunicated Honinbo, future 18th iemoto, and an excommunicated Hayashi (by the same guy). These people know each other. But, in general, my understanding is that Black should be solid and White should risk more, to offset the advantage. I think I understand the early moves in that corner, specially Black's. The two space on the side is a choice, I suppose, to risk putting the corner under pressure in exchange for separating White from the stones it already has. I'd, personally, probably miss that second stone and mess it up, but from away it looks logic.

But I don't understand 16. It doesn't feel urgent. And, if it was, White is less strong in the area than it was before. Why now?

All said, I like Black's SE corner, her West, and White's North and South. The NE? Well, despite all the manouvering they manage not to become one of those modern compact messes with no space to breathe. For what's worth, my pocket version of KataGo seems to want to settle 42 at 39 and, earlier, attach 16 at R7, but 39 seems a very AI move.

Take care.

_________________
一碁一会

I does look like a "please don't kill me" move. Black makes eye shape while white gets to protect a weakness. White's weakness was more painful than black's.

Possibly black wants to try to win effortlessly given the handicap. Really a professional attitude That would explain why he jumps on the opportunity to make a no-worry group.

A normal joseki in this corner would sort of give black a no-worries group, but he may have wanted to get into the center too.

Click Here To Show Diagram Code

[go]$$B
$$ +--------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . X . . . . . , . . . . . X . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . 2 . .|
$$ | . . . , . . . . . , . . . . . , . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . O . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . O . .|
$$ | . . . X . . . . . , . . . . . X O . .|
$$ | . . . . . . . . . . . . O . X . X O .|
$$ | . . . . . . . . . . . . . . . . X 1 .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]

I'm not sure but black might have had in mind that it isn't automatic that he can attack if he plays a forcing move from the other side. For example:

Click Here To Show Diagram Code

[go]$$B
$$ +--------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . 2 . .|
$$ | . . . X . . . . . , . . . O . X . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . O . O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . X . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . , . . . . . , . . . . . , . . .|
$$ | . . . . . . . . . . . . . . . . X . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . O . 1 .|
$$ | . . . . . . . . . . . . . . . 5 3 . .|
$$ | . . . . . . . . . . . . . X . 4 O . .|
$$ | . . . X . . . . . , . . . . 6 X O . .|
$$ | . . . . . . . . . . . . O . X . X O .|
$$ | . . . . . . . . . . . . . . . . X . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]

If white skips a move, then he might prefer the following way instead. It is lot less effort for black, however white wouldn't allow this. Black appears to help white more than himself in the game, when white simply protects.

Click Here To Show Diagram Code

[go]$$W
$$ +--------------------------------------+
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . 1 . .|
$$ | . . . X . . . . . , . . . O . X . . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . O . O . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . . X . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . , . . . . . , . . . . . , . . .|
$$ | . . . . . . . . . . . . . . . . X . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ | . . . . . . . . . . . . . . . O . . .|
$$ | . . . . . . . . . . . . . . . . 2 . .|
$$ | . . . . . . . . . . . . . X . X O . .|
$$ | . . . X . . . . . , . . . . . X O . .|
$$ | . . . . . . . . . . . . O . X . X O .|
$$ | . . . . . . . . . . . . . . . . X . .|
$$ | . . . . . . . . . . . . . . . . . . .|
$$ +--------------------------------------+[/go]