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Dragon Phoenix · Judge Doom

... that Tim Krabbe has put his site back up (see OT). Taken from the Dutch part of his site:

Chess Board

WKd2,WQf5,WRa4,WNc2,BKb1,BQa8,BNc7,BBa3,


BBc4,BPa2,BPb2,BPb5,BPd5,BPg4,BPh5

White to play (from bottom to top) and mate in 5 (Siers, 1959)

[This message has been edited by Dragon Phoenix (edited 04-28-2002 09:14 PM).]

ctrlaltdel · Member of the Daedalians

huh???

am i missing something again???

white has a mate in two!

1. Nxa3++ Ka1
2. Qb1#

mole · Subterranean Member

2... axb1 maybe?

ctrlaltdel · Member of the Daedalians

heck thats right... and it even says white playing from bottom up, DUHH

borschevsky · Chessnut

Yes, but if axb1=Q then 3.Nc2 is mate, no?

However:

2..axb1=N and white has no mate.

borschevsky · Chessnut

Well, Qf1 would be mate right now if it wasn't for the Bc4, so maybe RxB to remove the bishop, or just Qf2 to try for Qe1# next. But in both cases black can just go a1 to open a hole on a2.

borschevsky · Chessnut

Oh, what about...

1. Qf2 a1=Q (to stop Qe1#)
2. Qf5! to re-threaten discoveries by the knight

If black does nothing constructive, then 3. Nb4+ and Qc2# (black can waste a move with Bd3 but white is in time)

2...Qa2
3.Nxa3+ Ka1 4.Qb1! Qxb1 5.Nc2#

I don't think I've checked all the variations, but that has to be right. It's too pretty to have a refutation

.

Dragon Phoenix · Judge Doom

Yes, that's correct. Well done - as expected!

The theme is that the black pawn does not promote but degrade to a queen. When the new black queen comes to a2 where the pawn came from, it is less powerful than the pawn - it cannot promote to a knight.

ctrlaltdel · Member of the Daedalians

heres one variation...

1. Qf2! a1N
2. Qe1+ Ka2
3. Qxa1+ Kb3
4. Rxa3+ Qxa3
5. Qxa3#

[This message has been edited by ctrlaltdel (edited 04-29-2002 05:58 PM).]

Coyote · Posted: Tue Apr 30, 2002 12:26 am Post subject: 10

Believe it or not, I even 'read' the in het Nederlands section of Tim Krabbe's site (after all Chess is a universal language). That's why I didn't bother sticking my nose in this one.

Incidentally, the 'loss of promotion rights' idea has been done before. This one is an especially nice example though.

Coyote · Posted: Tue Apr 30, 2002 12:30 am Post subject: 11

Oops, just scrolled back up and checked the date of the problem's publication...disregard that 'has been done before' bit.