Comm., Die Schwalbe 1976
15+15. Position after Black's 4th move. How did the game go?
I will not insert the full solution, because you'll appreciate it even more when you discover it yourself. The same goes for all the dual-free Proof Games problems.
Here is a hint anyway: the bK captures the wB.
There is an anecdote attached to this nice (but tricky) little problem: the problem was discussed on Usenet <rec.games.chess> newsgroup several years ago. There it was said that Garry Kasparov had been seen trying to break this nut for several longish minutes before he eventually saw the light. (Indeed the problem is perverse because it is easy to reach the diagram position in 3 or 5 moves.)
Please, email me <retro(at)catv6081.extern.kun.nl> any info you have on this anecdote. When/where did this take place? Was Garry furious for being so slow ? Did he comment on Orban's deceptiveness? I'll pass along any info I get...