tygxc wrote:
@5855
First try:
Slightly shorter.
Shortest-proof-game challenge
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Kyobir wrote:
reach final position (#5856)
After you improve on Kyobir's 22-move game, see if you can improve on the 53.5 move game for this old position.
Nov 7, 2023
0
#5824
Kyobir wrote:
reach final position
Looks to me like the key to getting this shorter would be to make sure Black keeps capturing and ends with a capture on b4/d4.
amrugg wrote:
Kyobir wrote:
reach final position (#5856)
Looks to me like the key to getting this shorter would be to make sure Black keeps capturing and ends with a capture on b4/d4.
Here's one way to get it shorter.
n9531l1 wrote:
amrugg wrote:
Kyobir wrote:
reach final position (#5856)
Looks to me like the key to getting this shorter would be to make sure Black keeps capturing and ends with a capture on b4/d4.
Here's one way to get it shorter.
In reverse, this is optimal: https://puzzling.stackexchange.com/questions/45647/chess-the-lone-king
@5858
Slightly shorter
@5858
Slightly shorter
Nov 9, 2023
0
#5829
Fastest game where White to move is checkmate and Black to move is checkmate:
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Asymmetrical:
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More:
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Nov 10, 2023
0
#5833
Second challenge: find the fastest position where white/black to move is mate, but the queens never move and the queens are not the mating pieces.
BishopTakesH7 wrote:
Second challenge: find the fastest position where white/black to move is mate, but the queens never move and the queens are not the mating pieces.
A queen (or any piece) can never be a mating piece unless it moves anyway. Read this thread (all posts 
): https://www.chess.com/forum/view/endgames/how-can-you-deliver-checkmate-with-a-king
It is possible though to specify that the queen does not attack the king in the checkmate position.
dhruvstrathaim wrote:
n9531l1 wrote:
#925
what about
This is an illegal proof game by FIDE law as the position is "dead" (no one can checkmate the other side) after 17. .. Kxe7 which terminates the game automatically in a draw. To get the final diagram legally you'll need to make the rook capture as the final move on e8!
This issue has recently been discovered by the retro-community though I've known it for 15 years. It caused problems in standard compositions which were drawn before the point designated by the author. I think they changed the rule now or are in the process of doing so. One of these days I'll look where they have gone with it. Probably the wrong way as they have a habit of doing.
Note that "dead positions" are a basic FIDE law (article 5.2.2) and not some weird "competition rule" or "Codex convention".
Arisktotle wrote:
dhruvstrathaim wrote:
n9531l1 wrote:#925
what about
This is an illegal proof game by FIDE law as the position is "dead" (no one can checkmate the other side) after 17. .. Kxe7 which terminates the game automatically in a draw.
True, and that was noted when this game was posted a couple of years ago. Article 17A of the Codex says "Unless expressly stipulated, the rule of dead position does not apply to the solution of chess compositions except for retro-problems." This being a retro-problem, the dead position rule does apply.
@5855
First try: