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MatPlus.Net Forum X-Files: Anticipations Pam-Krabbe-Rochade, aka Extra-Long, Castling-Anticipated By 65 Years!
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(21) Posted by James Malcom (Rewan Demontay) [Friday, Jan 8, 2021 03:33]

Nikola, there are no details other than having one side do a PKC, while the other side castles on either side. The order of promotion and capture of the original is irrelevant. It just happens to be generally easier to promote after, it seems. It is also easier to verify a PG if PKC is the last move.

Oh, and as to your PG 7.5, Jacboi C+'s the first 7.0 moves, no orthodox solution in 7.5.

Nikola Predrag, Previous Post As Implied
PG 7.5
(= 14+14 )

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(22) Posted by Andrew Buchanan [Friday, Jan 8, 2021 09:17]

Very nice Nikola, may I match your Bl kside with Bl qside?

(= 14+14 )
PG in 7.5
HC+ Natch:
0 sols in 7.5,
1 sol in 7.0, retracting 8.P-K
0 sol in 6.0, retracting 8.Ld3-g6 Dh2xTh1 7.P-K.
I think this is sufficient to validate
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(23) Posted by Nikola Predrag [Friday, Jan 8, 2021 18:08]

Thanks Andrew, btw what is Prenix?
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(24) Posted by Andrew Buchanan [Friday, Jan 8, 2021 18:43]

Phoenix is where an officer is captured, and *then* a friendly pawn promotes to that same kind of officer. But what if the pawn promotes *before* the officer departs? The term "phoenix" doesn't seem appropriate, since there is no rebirth, so several years ago the new term "prenix" was invented and accepted in the Retro Mailing List.

[Rest of post is shifted to "Nature of promotions" thread.]
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(25) Posted by Nikola Predrag [Friday, Jan 8, 2021 20:27]

Thanks Andrew, I had guessed so but Rewan's comment made me doubt a bit.
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(26) Posted by Joost de Heer [Saturday, Jan 9, 2021 10:38]

Some special cases have a different name:
If the promoted piece is captured without ever moving, and the promotion is exactly determined, it is called a Schnoebelen promotion.
If a p(hoe|re)nix is on the home square of the piece it replaced/will replace (or it can be proved that it visited that square), it's called a Pronkin.
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(27) Posted by Andrew Buchanan [Saturday, Jan 9, 2021 11:33]

Hi Joost,

There are more also specific terms. Schnoebelen promotion is a kind of Prentos promotion (= capture by officer) which is a kind of Ceriani-Frolkin promotion. Being Schnoebelen doesn't stop the promotion *also* being Prentos & C-F. There are many other thematic properties like Pronkin, Anti-Pronkin, Donati etc to classify. Joy.

[Rest of post is shifted to "Nature of promotions" thread.]
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(28) Posted by James Malcom (Rewan Demontay) [Saturday, Jan 9, 2021 17:46]

Joose, Andrew, and Nikola please stop hijacking this thread with all this talk of themes and keywords and such, and take it elsewhere. This thread is about Pam-Krabbe castling. It is interesting stuff, but you're literally taking over this thread, especially with Andrew's above long post.

Post 23 is fine, but all below it and this is draining the spirit out quickly.
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(29) Posted by Andrew Buchanan [Saturday, Jan 9, 2021 17:53]

Sorry James, you're right. I think it's mainly me, not Joost or Nikola :-) I will set up a new thread for this, and shift my own recent comments there
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(30) Posted by Nikola Predrag [Saturday, Jan 9, 2021 20:27]

Rewan, after I wrote a few sentences, you accuse me of hijacking this thread. How do you dare? Please think before writing! Consider that I'm offended (not seriously, don't worry).
I have no problem accepting harsh criticism and words when there's reasonable ground for that (even if not completely correct).
So please, explain what's my fault in your view.
Or you just want me to shut up?
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(31) Posted by Andrew Buchanan [Sunday, Jan 10, 2021 10:19]

Sorry for distracting everyone with my peerless (& endless) prose yesterday: when the Singapore monsoon ends I will be able to get out and about cycling again. Please don't fall out on my account :D

Here's another little P-K task...

(= 14+14 )
PG in 7.5
Natch v3.2 says
0 sol in 7.5
1 sol in 6.5 (R: 8.Qh8-e5+ 7.0^6)
0 sol in 5.5 (R: 8.Qh8-e5+ 7.g7-g6 Qh7xRh8 6.0^6)
I think this suffices for HC+ checking, any other cases?

Or can you mate the P-K castled king with a shorter Unique Proof Game, leaving standard material?
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(32) Posted by Hauke Reddmann [Sunday, Jan 10, 2021 10:53]

@everyone: please calm down, thread drift is a phenomenon
known since the earliest days of USENET, I'm guilty too,
but given the extremely low traffic of MPF compared to,
say, :-) I don't see
imminent danger of a thread becoming unusable.

That said, who does the fastest G (SP optional) with
all three white castlings in Circe Rex Inclusive? :-)
(The two orthodox probably have been done.)
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(33) Posted by Andrew Buchanan [Monday, Jan 11, 2021 06:47]

Check in Circe RI only exists if the king’s home square is occupied (including by the king itself, but not I suppose including the checking unit.)

How about castling? I guess can’t castle if K in check. But can be never be an issue if intervening square or target square is attacked, as the K has left an empty square behind him?

Where is this kind of precise precision documented? Some of the understanding here I got from the Retro Corner, but it doesn’t address corner cases. Juliefairies definition is more opaque and doesn’t touch the question of check. It’s not obvious for a newcomer to the fairy world how check would adapt to Circe RI. Please can it be updated to reflect this and castling.

Happy to act as a reviewer for JF definitions if requested. JF needs someone sympathetic on the outside e.g. me to provide fresh naive perspective, and I am very naive :-)
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(34) Posted by Joost de Heer [Monday, Jan 11, 2021 07:36]

 QUOTE if the square on which the king stands, or the square which it must cross, or the square which it is to occupy, is attacked by one or more of the opponent's pieces,

Where do you see the word 'check'? IMO this definition works well even with Circe RI. It even works in variants where the king isn't royal, it only doesn't work in variants where there is no definition of 'attack'.
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(35) Posted by Andrew Buchanan [Monday, Jan 11, 2021 08:25]

Hi Joost,

Thanks for the reply :-)

From the Retro Corner
Rex Inclusive Circe
Here the capture & rebirth rule also applies to Kings, i.e. they may be attacked and captured as long as the home square is free. Only if the home square is occupied, a King can be checked.

Are you still a moderator of this, btw?

The definition of check itself must be changed under Circe RI, because the rule is expressed in terms of piece being attacked. E.g. a problem of Dirk Borst’s I looked at last night has wBc6+ bKe8-d7. And therefore it is natural to look at the definition of castling, and try to interpret in a manner consistent with this. Merely attacking is obviously meaningless in Circe RI.

In my opinion, to attract newcomers to fairy chess, we can’t just present existing FIDE rules and expect the novices to interpret them in the same way as expert practitioners do. We need to make the effort to explain how the interpretation should be made, including all corner cases. There is no “spoiler” here. The fun of solving actual problems remains intact - indeed it’s better and much more satisfying because the solver is on a sure foundation of knowing how these weird rules are meant to work.

I do agree we should try to ensure that fairy rules are written in a way that does allow for a natural interpretation to apply as much as possible, so that where four fairy conditions interact they can do so in as predictable and repeatable a manner as possible. We can’t explain everything upfront. I have some ideas about that too but that’s not the situation here: this is a single relatively common variant of the most common fairy condition of all, and it merits a proper explanation

So please tell me how Circe RI is meant to work
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(36) Posted by Andrew Buchanan [Monday, Jan 11, 2021 14:18]

(= 5+3 )
#1 Circe RI (2 sols)
(According to both Popeye & WinChloe.)
If in the starting position, wK is in check (e.g. +bBf2) then there are no mates.
Note that if -Be8 and Re7 shifted to e8, then it's not mate because 1. ... Ke2,Ke3,Ke4 is legal.

So castling seems to depend upon a notion of transient check (check => occupation of king's home square, which is already empty by the time the king passes through that square) and not on attacking (the piece or the square). A piece on the enemy king's home square cannot give check. These aren't the rules: they are consequences of a proper definition of check & castling in the context of Circe RI.
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(37) Posted by Hauke Reddmann [Monday, Jan 11, 2021 17:32]

Here is a PG (not necessarily S and surely not unique)
for three white castlings in CRI:
1.d4 e5 2.e4 Qg5 3.Bc4 Qxc1 4.Sf3 Qxb1 5.O-O exd4(Bd2) 6.e5 Qxd1 7.e6 Qxf1(Rh1)
8.e7 Qxg1+(Ke1) 9.Bf1 Kd8 10.O-O-O Qxf2 11.e8R Qxd2 12.Bc4 Qxc1(Ke1) 13.P-K
As you see, I waste time due to not being able to castle out of a check.
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(38) Posted by Michel Caillaud [Tuesday, Jan 12, 2021 00:16]

Quite an exciting idea Hauke! but I am afraid producing a sound realization will be quite demanding (if possible).

Here is something more simple to complete the basic cases with a theme not yet associated with the topic

(= 15+14 )
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(39) Posted by Joost de Heer [Tuesday, Jan 12, 2021 20:23]

Two castlings has been done before: (twice white 00) (white 000 and white 00)

Antisupercirce might be a good condition for all three castlings.
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(40) Posted by Andrew Buchanan [Wednesday, Jan 13, 2021 02:37]

Thanks - the PDB documentation for antisupercirce isn’t very good and it doesn’t mention type Cheylan - if someone can please tell me what it means I will update the glossary and get the animation working properly.
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MatPlus.Net Forum X-Files: Anticipations Pam-Krabbe-Rochade, aka Extra-Long, Castling-Anticipated By 65 Years!