Crazyhouse castling rules

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Nordlandia
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Crazyhouse castling rules

Post by Nordlandia » Sun Oct 20, 2019 12:05 pm

I was advised to consult this forum after a lengthy conversation on "discord" with mixed opinions. Do you think that's okay to being able to castle with dropped rook in crazyhouse?

There is mixed opinions on this and few sources say it's legal while other sources say it's forbidden.
A Rook dropped onto either Rook home square is considered not to have moved; so one may castle with such a Rook. A similar rule applies to a Pawn dropped onto the second rank: The Pawn inherits the two-step-move option along with the risk of en passant capture.
What is your say on this?

Sources:

http://www.bughouse.info/academy/rules.html

https://www.chessvariants.com/multiplay ... andem.html

http://bughousechess.wz.cz/CompleteBugh ... sRules.htm

Toadofsky
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Re: Crazyhouse castling rules

Post by Toadofsky » Sun Oct 20, 2019 12:10 pm

Indeed, this seems the best place (at least that I'm aware) to reach out to chess engine & UI developers, as well as the larger community, to hear their thoughts on the matter.

I don't mind coding into multi-variant SF whatever we decide upon.

Ferdy
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Re: Crazyhouse castling rules

Post by Ferdy » Sun Oct 20, 2019 12:49 pm

Nordlandia wrote:
Sun Oct 20, 2019 12:05 pm
A Rook dropped onto either Rook home square is considered not to have moved; so one may castle with such a Rook. A similar rule applies to a Pawn dropped onto the second rank: The Pawn inherits the two-step-move option along with the risk of en passant capture.
The issue with missing rook is that the castling right is also missing even in FEN. When one drops a rook, does it restore the missing castling right? also in FEN? I think a dropped rook should not restore the castling right? Castling usually involves virgin squares. For white, A1, E1, and H1 should be virgin squares from startpos. During a game the moment A1 is emptied or a capture happened, it is no longer a virgin square. Dropping a rook there does not restore its virginity - this is HGM's term :)

In the case of a pawn on the 2nd rank, there is no such thing as 2-step rights and it is also not represented in FEN. So a pawn dropped on the 2nd rank can have 2-step capability.

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hgm
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Re: Crazyhouse castling rules

Post by hgm » Sun Oct 20, 2019 1:47 pm

The way I understood the Crazyhouse rules is that the Pawn has a location-dependent move (so it can always do a double-push from 2nd rank, no matter how it got there), while castling rights depend on history. Obviously returning a Rook to a1 through a board move should destroy its castling rights; it would be illogical if returning it there through a drop move would revive those.

adams161
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Re: Crazyhouse castling rules

Post by adams161 » Sun Oct 20, 2019 11:45 pm

my understanding is that the rook and king must not move to be able to castle. if the rook leaves that square the rights to that side castle are gone. Dropping it there to me seems no different than simply moving it back there with a regular move. So i have programmed my pulsar chess engine which plays crazyhouse to consider the rights gone once a rook or king moves.

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Nordlandia
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Re: Crazyhouse castling rules

Post by Nordlandia » Mon Oct 21, 2019 5:11 am

Let say black captures the rook on h1 with the bishop on b7. White recaptures the rook later on and drop it back in the corner. Now the king and the rook has established link / connection again. Castling can in theory be available once again on that side (Kingside castling for white).

Other sources suggests dropping the rook on the starting square is considered to not have been moved earlier.

One argument for this is that Queenside castling is in most cases considered too dangerous in Crazyhouse. One can drop heavy pieces in the corner. So kingside castling is usually essential in Crazyhouse.

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Ovyron
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Re: Crazyhouse castling rules

Post by Ovyron » Mon Oct 21, 2019 7:34 am

My take on this: the rules of the game depend on the site the game is played on. We already have different chess servers implementing the game with different rules and still calling it "crazyhouse."

So, whatever definition of the game "crazyhouse" is the correct one, the important decisions have already been made when the variant was implemented in chess servers.

The major servers that have implemented crazyhouse are FICS, Chess.com and Lichess, if you want to play crazyhouse, those are the places you visit. And when they implemented the rules of the game, they decided that castling rights aren't restored for dropped rooks.

This has resulted in 99% of ZH games being played without restored castling rights. If a chess server changed the rules of the game to restore castling rights, then all the past games without it wouldn't have been "crazyhouse" games anymore, so what should we call them?

Note I used the word "change" in my last paragraph, did that sound weird to you? No, because the fact would be that those chess servers would need to change the rules of the game to accommodate for the different ruling.

What is being suggested is a rule change.

It then sounds like crazyhouse with restored castling rights is a variant of that game (can it even be played somewhere?) so my suggestion would be for people to implement this variant in their servers and give it a different name (drop chess, mad chess, reinforcement chess, turnabout chess and schizo-chess are apparently available) and test it out. If it works and people prefer the variant you just let crazyhouse die and move on.
Great spirits have always encountered violent opposition from mediocre minds.

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Nordlandia
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Re: Crazyhouse castling rules

Post by Nordlandia » Mon Oct 21, 2019 11:37 am

They probably didn't consider this rule "appendix" back in the early internet server days. No excuse for for that.

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hgm
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Re: Crazyhouse castling rules

Post by hgm » Mon Oct 21, 2019 1:28 pm

Not sure what 'appendix' you are referring to. But it probably did not exist when the major servers came into existence.

What makes you think they have any authority even now? Every idiot nowadays can make a website with a fancy domain name, and advertize whatever rules he pleases on it.

Also note that in the early days rules have not been the same everywhere. In the seventies I have participated in a tourament of a bughouse-like game ('doorgeefschaak') organized by the dutch Chess association, where it was not allowed to drop pieces with check.

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