Life In 19x19

Problem C has two solutions, the other one is:

$$B Problem C
$$ | . . . . . . . .
$$ | . . X X X . . .
$$ | . O X O O O . .
$$ | . X O X X O . .
$$ | . X O . X O . .
$$ | . X O . X O . .
$$ | . 1 . . . . . .
$$ ----------------

Note that in most situations, this answer is the better of the two ...

One possible reason is that whoever gets to fill the G1 ko gets extra ko threats in the upcoming ko fight on the right hand side:

$$Bc Move #241, Game 2, Gu Li vs. Kim Jiseok
$$ ---------------------------------------
$$ | . . . . O . . . O . . . O . . . . . . |
$$ | . . . . O X X X O . O X O X X ...

Ok, apologies for the multiple posts, but thought I should put some substance to my comments. Here is the best I can see for black playing first:

$$Bc
$$ | . . . . . . . O X . . . . . . . . . . |
$$ | . . . . . . O X . . . . . . . . X . . |
$$ | . . O . . . O X . . . . . . . . . X 9 ...

Ok, on reflection I don't think black can capture any stones, but seems like black can gain a couple of extra points beyond the obvious ones, so still worth looking into the variations when black plays first and white tenukis.

You didn't show the variations when black plays first and white tenukis. Can't black go on to capture 3 stones in gote by exploiting the life&death issue of the corner? Doesn't that make it more than 4 1/6 points sente?

This is a nice shape, and I would like to put it or some variation of it on goproblems.com if it's not already there. Could I have your permission to do that (I would give credit of course), or maybe you'd like to do it yourself?

Thanks!

To follow up on the above, it would be wrong to capture white 6. It would lead to ko, as in the following main line:

$$Bcm1 ...