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Re: Engines playing Musketeer Chess, good price

Posted: Sat Feb 15, 2020 4:22 pm
by hgm
Ferdy wrote:
Sat Feb 15, 2020 11:46 am
Ferdy wrote:
Fri Jan 17, 2020 7:27 am
Specific rule when the king is in check and this king has a musketeer piece behind it for gating. Rules at site will be updated soon.

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Code: Select all

****c*l*/r3kBnr/1pp1pB1p/p1np2p1/P5qb/4P3/3P1P2/1PP3PP/RN1QK1NR/*C****L* b KQkq - 0 1
Black to move its king is under attack.
* Black can only gate (the cannon, see image above) if the king can capture its attacker (White bishop at F7 square).
It seems like winboard 4.20200207 misses the rule on gating when king is under attack. If black plays Kxf8 or e8f8, it should not gate the cannon. The only move that can gate the cannon is by the move Kxf7 or e8f7 (a move where the king itself captures its attacker).

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What silly rule is that? It defies all logic. I propose to drop that rule.

Re: Engines playing Musketeer Chess, good price

Posted: Sun Feb 16, 2020 1:36 am
by Ferdy
hgm wrote:
Sat Feb 15, 2020 4:22 pm
Ferdy wrote:
Sat Feb 15, 2020 11:46 am
Ferdy wrote:
Fri Jan 17, 2020 7:27 am
Specific rule when the king is in check and this king has a musketeer piece behind it for gating. Rules at site will be updated soon.

Image

Code: Select all

****c*l*/r3kBnr/1pp1pB1p/p1np2p1/P5qb/4P3/3P1P2/1PP3PP/RN1QK1NR/*C****L* b KQkq - 0 1
Black to move its king is under attack.
* Black can only gate (the cannon, see image above) if the king can capture its attacker (White bishop at F7 square).
It seems like winboard 4.20200207 misses the rule on gating when king is under attack. If black plays Kxf8 or e8f8, it should not gate the cannon. The only move that can gate the cannon is by the move Kxf7 or e8f7 (a move where the king itself captures its attacker).

Image
What silly rule is that? It defies all logic. I propose to drop that rule.
The idea is something similar to castling rights where if the king is under attack and is forced to move, it loses the right to castle. In here black loses the right to gate but with one exception that is, it could still gate if the king itself captures its attacker.
This adds tactical awareness to the game when a musketeer piece is dropped at king file, hoping to get it centralized after a gate move but with a risk of being not able to gate.

But of course it is up to the inventor.

Re: Engines playing Musketeer Chess, good price

Posted: Sun Feb 16, 2020 5:27 am
by hgm
Does this have any effect on real games at all? The position you show does not look like it was from a game, as black should have captured Kxf8/E on the move before he was checked. Allowing a gating piece to be attacked is usually losing anyway, even when it is still allowed to gate, as the Musketeer pieces belong to the most valuable ones, and it will be captured after gating. Besides, allowing your King to be forced to move before you castled would be bad anyway, for the loss of castling rights, so you would not do it for that reason alone. Postponing gating is an unnecessary risk; postponing castling is an unnecessary risk.

This just seems to be 'rules for the sake of rules', a complex rule addition that would never be invoked in practice. You might as well add rules that if the opponent King is bare and on a square of opposite shade from your own King, you are allowed to remove one of your own pieces instead of a normal move...

The way to check if a rule affects the game is to play an engine that knows the rule against one that doesn't, and measure in which fraction of the games the latter one would infringe the rule. My gues is that you could play tens of thousands of games that way without ever seeing a gating on King withdrawal after check.

Re: Engines playing Musketeer Chess, good price

Posted: Sun Feb 16, 2020 6:55 am
by Ferdy
The sample position is not from real games. It is just a composition to show the rules. For human vs human games this is interesting.

Re: Engines playing Musketeer Chess, good price

Posted: Sun Feb 16, 2020 10:07 am
by gbtami
[/quote]
What silly rule is that? It defies all logic. I propose to drop that rule.
[/quote]

+1

Re: Engines playing Musketeer Chess, good price

Posted: Sun Feb 16, 2020 2:07 pm
by Daniel Shawul
For the record, nebiyu misses this rule too. e9f9 is a bad move but I don't see why it is not allowed?
Gating always occurs the first time the piece in front moves, right?
The idea is something similar to castling rights where if the king is under attack and is forced to move, it loses the right to castle. In here black loses the right to gate but with one exception that is, it could still gate if the king itself captures its attacker.
But castling and gating rights are different. You could lose catling rights while gating with all four moves: e9f8, e9d8, e9f9, e9d9. In all but one of the moves, it looses the cannon but why restrict the available moves to just one of them that won't loose the cannon?
This adds tactical awareness to the game when a musketeer piece is dropped at king file, hoping to get it centralized after a gate move but with a risk of being not able to gate.
Isn't that the same for all other gating moves that don't involve the king? The piece in front of a gating piece is always under pressure to move asap.

Re: Engines playing Musketeer Chess, good price

Posted: Sun Feb 16, 2020 3:10 pm
by Ferdy
Daniel Shawul wrote:
Sun Feb 16, 2020 2:07 pm
For the record, nebiyu misses this rule too. e9f9 is a bad move but I don't see why it is not allowed?
Gating always occurs the first time the piece in front moves, right?
Right except when the king is under attack, it could not gate. However if the check evasion is a king capture to the attacker, it can gate.

This is like a punishment for the side whose king is in check and the king is forced to move without capturing the attacker itself (king captures the attacker). Example is when a knight checks the king, here the king cannot capture the knight, so it could not gate if it evades the check by moving the king. This is part of the risks when one drops a musketeer piece (in the gating preparation phase) in the king file, as we know the king file is one of the central files of the board where deploying for example a chancellor (R+N) is very tempting.

Just a ref. for losing the right to gate is at https://github.com/fsmosca/musketeer-ch ... ht-to-gate
Legal gating is at https://github.com/fsmosca/musketeer-chess#1-gating

Re: Engines playing Musketeer Chess, good price

Posted: Sun Feb 16, 2020 4:36 pm
by Daniel Shawul
Isn't losing the gating piece when king is in check already punishment enough?
It would be simpler to just allow gating every time the piece in front moves, and then let the consequences (e.g. gating piece being immediately captured being one of them) prevail. If the king is incheck, obviously the gating can not occur by castling, but it should happen by all other means. In your example of a Knight checking a king, if the king moves and is allowed to gates, then the consequence is an exchange of a Cannon for knight. If the king is not allowed to gate, it would loose a Cannon so the punishment is more. It just adds more complexity, but there is no obvious need for the rule, sorry if I misunderstood your point.

Re: Engines playing Musketeer Chess, good price

Posted: Sun Feb 16, 2020 4:38 pm
by hgm
Ferdy wrote:
Sun Feb 16, 2020 3:10 pm
This is part of the risks when one drops a musketeer piece (in the gating preparation phase) in the king file, as we know the king file is one of the central files of the board where deploying for example a chancellor (R+N) is very tempting.
Except that when one drops a piece behind a King, one does it because one intends to castle quickly, long, long before the opponent has any chance to check you. One doesn't want to spoil ones own castling by making another move with the King just to gate. One doesn't want one's King to move, destroying the possibility to castle, even if it doesn't gate anything. It is generally advisable to gate under pieces that will be developed quickly, as not having gated does not only pose the risk of the opportunity being destroyed, but also lowers your instant tactical power. Having a Chancellor in the central files is good, but only if it is actually there (i.e. is gated). Even having a Chancellor in the corner is better than having an ungated Chancellor; ungated Chancellors are not only completely useless, they are in great jeopardy. They can be captured, but are not allowed to move. If you choose a gating square out of necessity, because the gated piece is needed there to neutralize a tactical threat, this would also only work if you gate it in time to fight off the threat.

It seems there is no use case for this rule in a serious game. Having the rule seems as pointless as adding a rule that you are allowed to remove your own queen on the move after the opponent moved a Kight backwards.

Re: Engines playing Musketeer Chess, good price

Posted: Sun Feb 16, 2020 5:04 pm
by Ferdy
Daniel Shawul wrote:
Sun Feb 16, 2020 4:36 pm
Isn't losing the gating piece when king is in check already punishment enough?
That is the point one has to take the risk when planning to gate at king file. The advantage however is that one can have a centralized piece after a successful gating.