|(1) Posted by Rewan Demontay (Real Name: James Malcom) [Sunday, Jun 6, 2021 02:28]|
A new(?) last move idea
I dug up a tiny retro I made.
Checkmate. Last Move?
(= 4+2 )
It's easy to solve I'd save. I think that, if not thought of already, we could do a few new problems with this idea. It's very likely that this has been done though.
|(2) Posted by seetharaman kalyan [Sunday, Jun 6, 2021 13:38]|
Last move? tasks have all been done already. The challenge is merely to improve economy. Actually white rook or black pawn not needed for this. King in check is enough to prove last move!
|(3) Posted by Siegfried Hornecker [Sunday, Jun 6, 2021 23:00]|
But then the last move would not be unique, as it wouldn't be a checkmate.
|(4) Posted by seetharaman kalyan [Monday, Jun 7, 2021 06:16]|
Sorry. Yes, you are right. Only the mate symbol proves it, not the position itself.
|(5) Posted by Joost de Heer [Monday, Jun 7, 2021 08:48]|
There are, I think, several 'White to play and draw' compositions, most of them by Plaksin, where the drawing move is castling, thereby proving the 50-move rule applies. Several have uniquely defined last move(s).
I've also seen a '#1. Last move?' where the solution was an e.p.-capture, so that the stipulation forced the last move.
|(6) Posted by Andrew Buchanan [Tuesday, Jun 8, 2021 02:56]|
Yes the problem in the base post is a constrained problem, where there is extra info provided in the stipulation. There is no convention which says one can take as a premise that a position must have a solution or a unique solution. On the other hand one can assume that a position is legal, until proven otherwise.
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MatPlus.Net Forum General A new(?) last move idea