I worked on this problem all day yesterday and this morning solving it- it is as tough a problem as you will ever find. I got what white's main winning idea is almost from the start, but it is finding out how implement it that is so challenging- black can defend every try except for one, and finding that one right method is like trying to find a particular needle in a stack of needles. Right now, I am working on the problem that shared 1st prize with this one- can't see how that happened, but will know more later.