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MatPlus.Net Forum Competitions The Problemist 1991 #n award

The Problemist 1991 #n award

Is it please possible to publish on the internet, or to send me, the award of The Problemist 1991 #n? I am curious about it since a pretty easy and straightforward Nunn problem received the 1st Prize, original publication of the problem: The Problemist, March 1991

http://pdb.dieschwalbe.de/search.jsp?expression=PROBID=%27P1294040%27

1st Prize in The Problemist for more-movers in 1991 went to Kwiatkowski.

John Nunn's problem won 1st Prize in a TT for problems featuring consecutive corner-to-corner moves.

That makes sense. But isn't there a dual in the end? 23.b3+ Sxb3 24.Bc6# instead of the other way around?

The solution in The Problemist ends 22.Bb4 Sd2+ 23 Bxd2 e1Q 24.Bc6

Thanks, Michael. That clears also my question.

Black should sacrifice 3 pawns on h1, but keep the 4th one on h2 as otherwise bSd8 loses its impact. So 18. Ba8! Sb7 19. Bxb7! and Black now sacrifices Bf1 & Ph2 in either order. Now 21. ... Sf3 22. Bb4! is the cleanest line, with a transposition dual only after 22. ... Sxd4 23. b3+,Bc6+. (21. ... Se4 22. Bb4,Bf3,Bg2/h1 etc is more geometrically dualized, however.)

It's funny that this problem attracted attention in Matplus just before Valery Liskovets' parity article appeared in Problemas April 2017. The initial position could have Bg2 or Bf3 instead of Ba8, allowing White to choose which corner to occupy, but then White would pick the faster solution, missing the record.

Since White has chosen this "slower option", of allowing the last pawn to promote rather than blocking it on the second rank, Black would allow a shorter mate if he tried to change the parity with h7-h5. The position at 16.0 would be like in the main line, except bPh3 is already further on at h2, so 17. Bh1! gives a short #22.

MatPlus.Net Forum Competitions The Problemist 1991 #n award