Check out Symmetric Chess, our featured variant for March, 2024.


[ Help | Earliest Comments | Latest Comments ]
[ List All Subjects of Discussion | Create New Subject of Discussion ]
[ List Latest Comments Only For Pages | Games | Rated Pages | Rated Games | Subjects of Discussion ]

Comments/Ratings for a Single Item

Later Reverse Order Earlier
Duck Chess. A Duck that must be moved by both players can block your moves. (8x8, Cells: 64) [All Comments] [Add Comment or Rating]
Michael Nelson wrote on Sun, Dec 24, 2023 01:21 AM UTC:

Would letting Black place the duck after his first move provide a more balanced game?


📝H. G. Muller wrote on Sun, Nov 5, 2023 08:03 AM UTC:

True, but why would white move the Duck to g6, if moving it anywhere else would force black to sacrifice his King? If white wants to lose he could simply resign. So from a game-theoretical POV there is no extra move option here.


David Paulowich wrote on Sun, Nov 5, 2023 12:02 AM UTC:

Back on 2005-03-08 a BLOCKADE STALEMATE IN 20 MOVES was posted on the SHATRANJ rules page. I believe that a similar stalemate can be achieved here in 15 or 16 moves. See the diagram below.

diagram

The White Rook previously captured a Bishop on (a6). After capturing a Knight on (e6) and moving the Duck to (g6), the game ends with a stalemate (and Black wins).


🕸Fergus Duniho wrote on Fri, Nov 3, 2023 10:25 PM UTC in reply to Bob Greenwade from 09:54 PM:

Okay.


Bob Greenwade wrote on Fri, Nov 3, 2023 09:54 PM UTC in reply to Fergus Duniho from 09:33 PM:

The Rules say here that "There is no check in this variant."


🕸Fergus Duniho wrote on Fri, Nov 3, 2023 09:33 PM UTC:

While playing this, it let me castle while in check. Here are the moves:

  1. e4 Dd6
  2. c5 Dc7
  3. Bc4 De6
  4. d6 Dd7
  5. Qf3 De6
  6. Nf6 Dd3
  7. Nc3 Dd7
  8. h5 Dd3
  9. Nd5 De6
  10. Nbd7 Dd3
  11. Ne2 Dc7
  12. Nxd5 Dg4
  13. Bxd5 Df6
  14. Ne5 Dg4
  15. Qf4 Dd3
  16. e6 Dc4
  17. Bxe6 Dd3
  18. Bxe6 Dg1
  19. Qe3 Df3
  20. Nc4 Df4
  21. Qd3 Dd5
  22. Ne5 De7
  23. Qb5 Dd7
  24. Nc6 Db6
  25. d4 Da6
  26. Qb6 Dxd4
  27. Qxb6 Dd8
  28. axb6 Dg1
  29. Bg5 Df6
  30. Nb4 Dg1
  31. c3 Dc2
  32. Nd3 Db8
  33. O-O

Kevin Pacey wrote on Mon, Feb 20, 2023 09:51 PM UTC:Excellent ★★★★★

A cute and cool variant!


📝H. G. Muller wrote on Wed, Feb 1, 2023 11:27 AM UTC in reply to Tamás Bajusz from 11:22 AM:

Thanks for the info. I added the link in the notes section.


Tamás Bajusz wrote on Wed, Feb 1, 2023 11:22 AM UTC:

Anyone can play Duck chess online on https://www.pychess.org as well. https://www.pychess.org/news/Duck_Chess


📝H. G. Muller wrote on Thu, Jan 19, 2023 09:49 AM UTC in reply to H. G. Muller from Tue Jan 3 09:54 PM:

The AI of the Diagram now also understands the trick of reserving a square for your next move by playing the Duck there, as you can verify by setting up a position through h7-h6, g7-h4, h2-h3, Ke8-h5, Qd1-d3. If at that point you switch on the AI, and play a useless move for black (e.g. a7-a6, Duck to a7), the AI will reply with Qf5, Duck to g5, and announce mate. (Which in this case does not end the game yet, but should be interpreted as announcement of King-capture in 2. In general the Diagram will allow you to play on when you are checkmated; if you do a pseudo-legal move there it will capture your King an announce "I win".)


📝H. G. Muller wrote on Tue, Jan 3, 2023 09:54 PM UTC:

I made a first attempt to make the Diagram play this. At the moment it still doesn't know the rule that you cannot leave the Duck where it is, although it effectively enforces that rule on the opponent, because its moving is triggered by moving the Duck.

This simplification makes it possible to treat it similar to Refusal Chess: the search just keeps track of the two best moves (in absence of the Duck), and only uses the score of the best if that is a contact capture (assuming the Duck would block it otherwise). In Refusal Chess you would always ignore the best move, assuming it will be refused. A refinement is that moves that have the same blocking square as the best move cannot become second-best (because then both could be blocked simultaneously). It only considers blocking on the first step of a slide, so it will overlook 'cross blocking' (where the Duck would block two moves going over the same square in different directions, and these happened to be best and second-best).

It will also overlook the possibility of 'reserving' your next move, as this cannot be done when moving the Duck is not mandatory. This will be hard to implement without making it very complex. Only moves with a single blocking square can be reserved, and it only makes sense to reserve a move that would refute the opponent's best reply to your current move. This would be an alternative method of 'disarming' his best move, which can be used when it is not possible to block that move. If it was blockable, so that both methods are available, it would make no difference which method you used, as both would make him fall back on his second best move. Unless the move you reserve refutes that move too. The chances that several moves are refuted by the same (reservable) move are a lot larger than those that you can block several independent moves (i.e moves that are not part of the same slide): you only need a hefty threat (like a check), and most of his moves are out. It must be possible to design a not-too-complex algorithm based on that idea.


Greg Strong wrote on Mon, Jan 2, 2023 02:33 PM UTC in reply to Jean-Louis Cazaux from 12:10 PM:

Yes, nice page. I have published it.


Jean-Louis Cazaux wrote on Mon, Jan 2, 2023 12:10 PM UTC in reply to H. G. Muller from 10:18 AM:

Nice page and nice diagram


📝H. G. Muller wrote on Mon, Jan 2, 2023 10:18 AM UTC:

OK, I created a Duck Chess page. I think it is ready for publication, but even though I am an editor I consider it bad form to publish my own articles. So perhaps another editor could judge it.


14 comments displayed

Later Reverse Order Earlier

Permalink to the exact comments currently displayed.