The excelsior problem, posted by SwissGambit, in which a pawn delivers the mate, reminded me of the above composition.
White to play and mate the black king.
BUT:
1. In the final position the black king must be threatened by a white pawn.
2. White is not allowed to capture any black unit.
3. White is not allowed to lose any of his own units.
This means that wPc2 must somehow reach c6 or c7 without being captured by a black P and without white capturing a black P.
Originally posted by David113 [fen]6k1/5R2/1p1p1R2/1p1p1N2/1p1p1N2/1P1B1Q2/2P2B2/5K2[/fen]
The excelsior problem, posted by SwissGambit, in which a pawn delivers the mate, reminded me of the above composition.
White to play and mate the black king.
BUT:
1. In the final position the black king must be threatened by a white pawn.
2. White is not allowed to capture any black unit. ...[text shortened]... omehow reach c6 or c7 without being captured by a black P and without white capturing a black P.
c2-c4, with a discovered check from wRa2/wQa2 on bKd2/e2/f2/g2/h2
c4-c5, with a wR on a6, wQ on f6, bKc6 (all moves leading to the position must have been checks, otherwise b5/d5xc4)
c5-c6 mate
or... c6-c7 mate
or c7-c8=Q mate (if allowed?)?
Originally posted by heinzkat c2-c4, with a discovered check from wRa2/wQa2 on bKd2/e2/f2/g2/h2
c4-c5, with a wR on a6, wQ on f6, bKc6 (all moves leading to the position must have been checks, otherwise b5/d5xc4)
c5-c6 mate
or... c6-c7 mate
or c7-c8=Q mate (if allowed?)?
I don't know if c7-c8=Q# is allowed; anyway, in the intended solution the pawn is not promoted, so you should do it without a promotion.
Originally posted by SwissGambit This is the tricky part. If bK is checked such that he [b]must go to c6, then White's c5 will likely stalemate him [Pc5 has to be protected].[/b]
Not so difficult, for example after Kd7 - Qd8+ [supported by some other piece] - Kc6 - c4-c5 [supported by wNd3, probably] - Kb7 - Qd7+ - Ka8 - c5-c6 - Kb8 - ...
Originally posted by heinzkat c2-c4, with a discovered check from wRa2/wQa2 on bKd2/e2/f2/g2/h2
c4-c5, with a wR on a6, wQ on f6, bKc6 (all moves leading to the position must have been checks, otherwise b5/d5xc4)
c5-c6 mate
or... c6-c7 mate
or c7-c8=Q mate (if allowed?)?
I'm sorry; after c4 isn't the pawn lost? And what discovered check from which piece on a2? 😕 Must be missing something here.
Originally posted by curseknight I'm sorry; after c4 isn't the pawn lost? And what discovered check from which piece on a2? 😕 Must be missing something here.
heinzkat is talking about long-range plans, not immediate moves. He means that white will aim for a setup with wR on a2, and bK on [say] e2. At this point, if there are no other pieces in the way, c2-c4 will check the black King.
Originally posted by SwissGambit heinzkat is talking about long-range plans, not immediate moves. He means that white will aim for a setup with wR on a2, and bK on [say] e2. At this point, if there are no other pieces in the way, c2-c4 will check the black King.
Originally posted by David113 [fen]6k1/5R2/1p1p1R2/1p1p1N2/1p1p1N2/1P1B1Q2/2P2B2/5K2[/fen]
The excelsior problem, posted by SwissGambit, in which a pawn delivers the mate, reminded me of the above composition.
White to play and mate the black king.
BUT:
1. In the final position the black king must be threatened by a white pawn.
2. White is not allowed to capture any black unit. ...[text shortened]... omehow reach c6 or c7 without being captured by a black P and without white capturing a black P.
This task is fiendish... the walk of the Black King after c2-c4 must completely be executed with checks, the King has to walk from d2 to c6, completely 'guided' over some sort of path White must have made...
Originally posted by David113 [fen]6k1/5R2/1p1p1R2/1p1p1N2/1p1p1N2/1P1B1Q2/2P2B2/5K2[/fen]
The excelsior problem, posted by SwissGambit, in which a pawn delivers the mate, reminded me of the above composition.
White to play and mate the black king.
BUT:
1. In the final position the black king must be threatened by a white pawn.
2. White is not allowed to capture any black unit. ...[text shortened]... omehow reach c6 or c7 without being captured by a black P and without white capturing a black P.
Does black have to avoid quicker mates without a pawn (e.g. best play) or can he move Kh8 after Rg6+ for example?
Originally posted by heinzkat Well I suppose you don't want to work out lots of subvariations for deviation moves by the Black King - in the meanwhile no progression. Anyone else?!