chessjoker

Discussion of chess software programming and technical issues.

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hgm
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Re: chessjoker

Post by hgm »

True, but Rf8 covers that. And it still has some delaying tactics, starting with Jxd2+.

At the moment the Joker is on c6, it will recognize that it is lost pretty quickly. But the problem is recognizing it 6 ply earlier, so that it would refrain playing h5.
Pippo
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Re: chessjoker

Post by Pippo »

If for you is a consolation, this morning he sliced me :evil:

Anyway, I have set the time at 10 min and I think to let it so in the future
evert823
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Re: chessjoker

Post by evert823 »

Hi, just a small rule question.

Suppose Black has moved a Knight and White now promotes a pawn to Joker.

I suppose that this Joker, that was chosen as promotion piece, is immediately imitating a Knight.

After this promotion, it's Black's move again and Black wants to play his joker. In that case, Black's Joker is imitating White's Joker and that comes down to imitating a Knight.

Is this the correct interpretation?
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hgm
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Re: chessjoker

Post by hgm »

I wouldn't think so. White moved a Pawn. So the black Joker must imitate a Pawn. It is meaningless to say the Joker imitates anything when it is not your turn. There isn't any piece type that has any move when it is not your turn. And it can only become your turn because of a move of the opponent, and that move will decide what you are going to imitate in your own turn.

The only issue is really what the Joker imitates after a turn pass. A turn pass plays a role even in variants where it is illegal, because the fiction of a turn pass is needed to answer the question whether you are in check. And hence decides the difference between checkmate and stalemate, and whether you can castle.
evert823
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Re: chessjoker

Post by evert823 »

OK, but the first post in this thread states:
"- if a pawn promotes, joker copy the promoted piece"

I think that I can remember that Henk van Haeringen gave the same explanation about his version of the Joker. I'm not sure when, I think verbally during an OTB tournament.

In the scenario of promoting a pawn to a Joker and with this rule effective, I really think that the explanation that I gave is the only correct one.
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hgm
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Re: chessjoker

Post by hgm »

OK, I see. That is not the most common definition of an Imitator. But of course any designer of a Chess variant can make the rules as he pleases. But then questions like this can only be answered by the original designer, and I doubt that he is still around. I don't recall anymore how I implemented it in Fairy-Max.

Imitating the promoted pieces strikes me as quite illogical: promotion happens after the move; if a Pawn promotes to Knight it is through a Pawn move, not through a Knight move. The normal rule for Imitators is that they move as the last-moved non-Imitator. If the promotion counts as a Joker move then it wasn't the last non-Imitator move, so then your explanation would be correct.

It seems mostly a moot point, though; no one in his right mind would ever choose promoting to Joker. It is a very awkward piece. In a Pawn ending it is next to useless; it would not be able to stop a passer unless it was already in its path.