Ratings & Comments

I found the following search scheme to work quite well in games with drops: you distingush check-drops from other drops, and make a special move generator to selectively generate those (by generating retro moves for all piece types, starting from the King). At d=1 the only drops searched are the check drops; at d>=2 LMR reduces non-captures by 1 ply, and (non-check) drops by 2 ply.

In CrazyWa I used a King Safety evaluation that seemed to work quite well generically across many drop variants. It was kind of unusual by being asymmetric. It awardeds a bonus to the side to move which is the product of the hand value and the number of squares attacked next to the enemy King (the possible drop locations). The latter could be cheaply calculated as side effect of the move generation, while the hand value can be kept track of incrementally. The idea was that in games with drops 'initiative' is all important, and the side that has the initiative typically checks the opponent all the time (mostly through drops, and captures with the slider it just dropped when evasion was an interposition). The side that is in check will never evaluate, but extend for the evasion even at d=0. So the leaves typically have the side on move that has the initiative, and this player usually doesn't have to worry much about his own King Safety.

Xiangqi chasing rules indeed are very annoying; especially the fact that they are based on legal attacks and protects means that you have to search 3 ply ahead to judge them: one to play the attacks that are  chase candidates as a capture, then the possible pseudo-legal recaptures, and finally the potential King captures resulting from these. And you have to do that for every position in the repeat loop. Always for both sides, because they could be mutually chasing, and then it is a draw again.

It can be acceptable to only detect chases for repeats that have a certain minimum search depth left (say 4 ply).

In Pushpawn Chess a connected pawn on the fourth or fifth rank can push back an enemy pawn that is placed before it, provided that the square behind the enemy pawn is empty. A Pawn that is situated adjacent to a friendly pawn, diagonally or horizontally, counts as “connected”. This is a serious challenger to Fide chess.

The pawn chain emulates a medieval shield wall. As the pawn is blocked by a shield, it cannot capture directly forwards. Instead, it captures diagonally forwards, which was a typical method, also in the roman army. But there is a move missing, namely a push move. In the ancient and medieval battle situation, soldiers tried to push the enemy shield wall back, to create a breach. The new push move emulates this ancient tactics.

Pushpawn Chess (Zillions)

Ok I went back and checked on the castling using only the ChessV engine with default settings with me as white. I've been playing mostly standard, gothic, and omega. Of three quick openings/midgames, Omega alone castled. What seems to happen is that the engine will push pawns away from a potential castle position before it gets the chance to castle into it.

On a different note, I tried to get P2P.exe (http://hgm.nubati.net/p2p.html) to work with this to play over the internet, but through no fault of either programmer, it won't work. This is because when you bring up the engine settings there should be a specialized window, but in ChessV there is always the same variation, weakening, etc. I only bring this up bcs there might be an easy fix ;)

Can someone help us? We try to play Metamachy with Numerist, I have the black pieces. When I click on one of the 4 which are in the center of the board, it activates (with a framed square) the 4 squares in the center of my lines, but how to move the piece in those squares? I've tried to click, to hold and drop the piece, nothing works. I've tried with Safari and with Firefox. Am I doing something wrong? Thank you

I have tested the final presets for apothecary chess. They have shown no more trouble. I was wondering if people will be interested in an apothecary chess tournament. Here are the preliminary rules should it happen.

1. Each round a player plays a game of apothecary chess-classic and apothecary chess modern
2. In order to avoid bye, myself will play only if the number of players is odd
3. The tournament is a double round robin if there are 4 players, a single round robin if there are 6 or 8 players. A swiss system with 6 rounds if there are 10 or more players.
4. Should the tournament be a swiss system the pairings in round one will be random
5. Remember that there is a possibility that a game has finished 0.75-0.25. This will be used in rankings
6. Time controls are 1 move/day
7. There are no prices except for the honor of winning the tournament!

Edit : Please express interest by commenting in this post.

Nobody can't help?

Hello, I'm interested to participate in this tournament.

Hello, Having tried the Metamachy preset with a personal invitation to myself, when I click "... to move" for the first move, I have the message "The invitation to play this game hasn't been accepted yet." and it is impossible to do a move, even after going back to the menu and returning to the game log. Is it that? Maybe you can try to send an open invitation, that your opponent could accept. I seem to remember that there could have been issues with personal invitations in GC.

I'm interested too

the rook moves one or more squares towards the original position of the king; the king moves one or more squares towards the original position of the king.

Shouldn't the last word there be "rook"?

An alternative would be to make PxP a special case, in which no promotion can take place. Other pieces capturing a P could still promote, as could a P capturing another piece.

I tried modifying ChessV to play with this alteration and the results definitely look better. Before, the players would glob up in the center but both sides would try hard not to capture anything. This version still seems to have some significant moving about before captures start, but then play looks pretty normal. (I haven't studied the games in any detail.)

Here's a typical ChessV self-play game with the new restriction. Game runs for 84 moves before white mates. The first capture is on move 18.

You can download as a ChessV saved game file here. The include file to make ChessV play with these rules is here.

I just saw the variants and wow they're interesting

I would love to join the tournament but I sadly won't because of school

I will instead say Good Luck to the tourneys

We try to play Metamachy on Game Courier. I have blacks. I can't find how to move a piece to the central squares of my lines and then start the game. Is that preset bugging? Or are we missing something? Please help us to understand. Thanks a lot

New information on this thread: Another copy of this chess set has been found in an online posting on Board Game Geek!  Follow this link and scroll down to see the photo and comments: https://boardgamegeek.com/geeklist/276021/item/7825120#item7825120

Sadly this set is also missing the rules!  But I am attaching my most recent ruminations on what the rules were when I played the game in my youth :-)

Viking Chess Rules as best as they can be remembered – November 28, 2020

The goal of the game is to checkmate your opponent's king as in regular chess. 

Board: The board is made up of "rings" linking "crosses" (the spaces).  There is a centre space, the “star”, in the middle. 

Pieces: There is a king, 2 rooks (flat tops), 2 bishops (spikes) and 4 pawns per side.

All pieces start off the board.  

On their first turn (white goes first) each player places their king anywhere on the board on any space except the centre space (I believe that no piece could start on the centre star because it gives too much of an advantage to start there - but I am not 100% certain of the rule). 
In the second and subsequent turns, each player can either move an existing piece on the board or bring another piece onto the board as per turn 1.  

Different pieces move differently as follows:
-	Pawn moves one space in any direction 
-	Rook moves up to 3 spaces up or down, or one space to the side
-	Bishop moves up to 3 spaces around one of the rings, or one space up or down. 
-	King can move up to 3 spaces in any direction up or down

Once placed on the board a piece can enter the centre space or through it.

A player takes an opponent's piece by moving a piece into their opponent's piece's space.  Once a piece is removed from the board it cannot return.  I do not believe there is a rule to promote a pawn to a Bishop or Rook.

The King is the strongest piece on the board combining both the Rook's move (3 up or down) and the Bishop's move (3 around a ring in either direction). 

If the King is taken/mated the game is over.

Sorry if this isn't the best place to put this.

The best place would be on the page for the preset you are having a problem with. That way, an email could have been sent to the programmer. Since you did not do that, I emailed him for you. Hopefully, he will fix the bug.

Anyone else?

Thank you Fergus, you spotted our problem right!

Thank you for pointing that out. I have now reviewed Pritchard's encyclopedia myself and agree there is a resemblance to Jabberwocky chess, but with fewer circles and no Queen (the King becoming the most powerful moving piece). I think we are getting closer to the origin story here of this board.

Arne Basse, from what I understand was a furniture designer, not known for chess boards. But he or whoever came up with this game could have been influenced by Parton. The timing would have been right as the board was produced in 1966. I wish there was a way to find out more about whether there is an archive of his designs somewhere, presumably in Denmark.