Bulky Five Weird Cases
Everybody's familiar with the Bulky Five shape and it's key point, k. The only way to kill but is it the only way to live? Not as long as you don't mind leaving an extra threat. It may sound weird but other moves might come in handy in special situations.
In fact Black has a couple of ways of moving here. A total of six including k for immediate and unconditional life.
Playing c or d lets Black live but leave a threat for White.
Tenuki lets White kill with k leaving miai out of c and d (One Black threat).
Playing b allows White to kill by playing at k.
Last and indeed least good (Or is it?) playing at a - Dying in gote and leaving one threat for Black.
Surely it's obvious so far and why list it?
Well inspired by a recent "historical" problem and in the spirit of http://www.goproblems.com/prob.php3?id=1589 -
For how many of these moves can a board be created where they would be optimal? (Without sliding to "fun" type - Avoid get-a-jigo and best move for opponent kind of problem)
Well the question is basically if it might be useful to play a less than perfect move sometime... :S
Chris Hayashida: I find it hard to believe that someone can construct a problem with a 1/2-point ko at the end of the game with an unsettled group. If there were two unsettled groups, then surely living (or killing) the bigger one would constitute a better ko threat than using an "extra" move to threaten to live.