"Advanced" problems are an interesting thing. They're supposed to be difficult, usually targeting an expert practitioner in search of a real challenge. But, properly explained, such problems can be of great use to us lesser mortals, too. Today's problem, we think, is an example of that.
Black to Play and Win
It's definitely a Black win, but is this an "advanced" problem? We'd rank it perhaps as "advanced intermediate" rather than "expert." What do you think? The real point, though, is that the solution demonstrates a winning technique that is useful and practical.
When you've advanced your knowledge by solving the problem, advance your mouse to Read More to see the solution and explanatory notes.
Please read the notes as the solution has important variants.
30-25 22-18---A, B 25-22 18-15---C 22-18 15-11 5-9 6-2 20-16 13x6 16x14 Black wins.
A---The computer move is 10-7, giving up the man at once in order to prolong the ending. It's a typical computer calculation leading to a move that humans wouldn't generally play.
B---22-17 25-21 17-14 23-26 32x23 21-17 13x22 31-27 22x24 20x2 and Black goes on to win, but there are still a few tricks: 29-25 5-1 25-22 2-6 10-7 6-10 7-2 10-14 2-7 1-6 winning on the move. We don't have the original published solution (the problem dates to the 1920s) but we suspect this flashy line is what the problemist had in mind. And while the stroke is indeed noteworthy, the completion of the win is what's really instructive.
C--- 18-14 23-26 32x23 22-17 13x22 31-27 22x24 20x2 and play continues as in note B.