tderz: ... I think the problem should be labelled 'Black to play' (and not to give up 4 stones).
Malcolm Are you sure Black can avoid giving up the four stones?
My current understanding is, once Black plays her best move, White can then either choose to let Black live and capture the four stones, or choose to resist strongly and make a ko in which he risks his own group. A bit hard to put in a title.
Anyway I like problem titles to be as un-informative as possible. One shouldn't even have to put: 'Black to play'. I wonder how it is in the original chinese version.
tderz: I fully agree with you on all points w.r.t. giving information in titles in problems:
I meant to say I think the problem should be labelled 'Black to play'
and should not be called almost meaningless Problem (which is was called before I edited it)
nor 'to give up 4 stones'.
How wrong I was with my initial statement, posted two days ago (now deleted by Malcolm: tderz: Just at a first glance: this marked white stone makes no difference to the possible places for eye shape and the liberty difference of 1 seems not to be important here. Looked at the problem again for ages and could not get the solution when White defends in the strongest way, until ....
Malcolm Yes, I finally understood that part of the problem as well last night (2007-10-11). My opinion on the status of the position is the same as my initial comment (see above), but I hadn't fully understood the problem then. Now I feel I understand the problem - at about the 95% level! So I mean to do a WikiEdit on the solution page when I have the time.