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Capablanca Random Chess. Randomized setup for Capablanca chess. (10x8, Cells: 80) [All Comments] [Add Comment or Rating]
H. G. Muller wrote on Sat, Dec 4, 2021 10:13 AM UTC:

I have made an attempt to implement Fischer castling in the Interactive Diagram. There is no special XBetza notation for this; a shuffle game has to be specified with a 'nominal' setup. This setup defines (together with the XBetza normal castling definition) where the king must end up, and what the castling partners are (the corner pieces, which must be of equal type). If such a castling is defined, any shuffle that involves the king will then be restricted to make the king end up between the castling partners, and will activate Fischer castling.

To support the shuffle rules of Capablanca Random Chess I enhanced the Diagram's shuffle feature: An exclamation point before a piece in a shuffle specification now either means that pieces of that type should be equally distributed over square shades, or, when there only is one such piece, that it must remain on the shade it is already on. This way Q and A can be forced on different shades by putting them so in the nominal position, and order an extra shuffle of only Q and A to determine which one goes on which shade. The shuffle specs are thus QA,N!BR!AC!QK.

Initially a Diagram always shows the nominal position; there is no spontaneous shuffle. To shuffle you have to press 'Restart' in the AI control bar.

[Editor's Note: Disabling this diagram to keep it from interfering with the one on the page.]

<script type="text/javascript" src="/membergraphics/MSinteractive-diagrams/betza.js?nocache=true">
<div class="idiagram">

H. G. Muller wrote on Thu, Dec 2, 2021 07:26 PM UTC in reply to Thomas from 06:04 PM:

Umm, I did not even know this rule existed. WinBoard restricts the shuffle only to have the Bishops on different colors. I agree the rule makes no sense. I have also seen descriptions that did not allow the Bishops to be on adjacent squares. (That also seemed to make little sense.)

The Interactive Diagram would have to struggle to enforce this rule, because there is no way to tell it directly that a pair of pieces of different types would have to be placed on different square shades. As a work-around you could 'mark' the shades by piece type, by defining the nominal start position with a back rank RBRBNKNCQA, so that RNQ are on dark squares, and BKCA on light. You can then order a sequence of shuffles, RNQ,BKCA,QA,!BNRKC .

The first shuffle solely serves to put Q on a random dark square, the second to put A on a random light square, and the third then randomly swaps the two. The remaining pieces then have to be shuffled the usual way, i.e. the Bishops would have to go on opposit shades (indicated by the ! prefix).

I guess it would be useful to extend the shuffling capabilities of the Diagram with a prefix to indicate the piece should stay on the same color as it was in the nominal setup. Sy This would be indicated by #, then the shuffle instructions could be K#QC#AR!BN,QA, with a nominal setup where Q and A start on different shades.

Thomas wrote on Thu, Dec 2, 2021 06:04 PM UTC:Excellent ★★★★★

But why the limitation to set up queen and archbishop on different coloured squares, when they can change the square colour by moving like rook resp. knight?

💡📝Reinhard Scharnagl wrote on Sat, Jan 26, 2008 08:52 AM UTC:
In the case of a real free castling there is the possibility to also have castlings, wherein the king is making only one single step. Then an encoding as e.g. Kd1 is not sufficient to distinguish a castling move from a simple King's move. Moreover in traditional chess O-O and O-O-O is used. Thus the representation should be very related to that. using O-O-x has more common parts to those traditional forms than O-x. Thus I am preferring that. 
By posting here I intended to investigate the status quo of writing down castling moves in variants, before I would start to implement such abilities in SMIRF's successor application Octopus.

aronymous wrote on Fri, Jan 25, 2008 11:11 PM UTC:
How about this : Ko-a for castling to the a-file , and Ko-b for castling the b file, and so on ? or O-a , O-b .. etc

💡📝Reinhard Scharnagl wrote on Fri, Jan 25, 2008 05:02 PM UTC:
Hi Sam, there seem to be different kinds of free castling, thus including one-step-castlings. This is one reason and another, because a castling should be obviously in its notation Thus I would prefer adaptions to the classic notation. Another question is, that a GUI should be more flexible in accepting several kinds of notations. Nevertheless I try to unify such notations into a common mimic.

Sam Trenholme wrote on Fri, Jan 25, 2008 04:48 PM UTC:
For my own Schoolbook chess, which supports free castling, I just notate a castling move as the square the king moves to; for example, Kc1. Where the rook moves to is determined by where the king moves to, and the only time the king can move more than one square is when he castles, so this notation is unambiguous.

- Sam

aronymous wrote on Fri, Jan 25, 2008 02:42 PM UTC:
I suggest notating is as a King's move. Like 'Kb1'. This is a standard way to notate normal castling, btw.

Joe Joyce wrote on Fri, Jan 25, 2008 02:28 PM UTC:
Hi, Reinhard. Good that you're making free castling available in SMIRF. You might want to generalize all castling as 'OOx', where 'x' is the column ended upon, for consistency.

💡📝Reinhard Scharnagl wrote on Fri, Jan 25, 2008 01:33 PM UTC:
Well, having no suggestions yet, I made some myself:

All castlings placing the King three squares from the left white side will be written as O-O-O (standard).
All castlings placing the King two squares from the right white side will be written as O-O (standard).
All other castlings will be written e.g. O-O-b terminated by the King's target column letter, here 'b'.

Would that be acceptable?

💡📝Reinhard Scharnagl wrote on Fri, Jan 25, 2008 10:26 AM UTC:
I am just thinking it over, whether to support also free castling in SMIRF - the variation, where the King makes at least two steps, to enable an unambigious move entering via a GUI. Then a lot of other chess variants would be able to be supported. But there is a question left: how is the regular notation for those castlings? O-O and O-O-O would not at all be sufficient here.

SMIRF is downloadable at:

Sam Trenholme wrote on Thu, Aug 16, 2007 05:56 PM UTC:
I just gave this program a test spin last night. So far, it looks good; its mating power and willingness to make sacrifices makes for some very exciting games to look at. I'm glad to see an exciting Chess variant player.

Zillions' game playing style is, in comparison, sterile and drawish. To make a comparison, Zillions is Kramnik's ice and SMIRF is Topalov's fire.

💡📝Reinhard Scharnagl wrote on Wed, Aug 15, 2007 11:50 AM UTC:
Hi Sam, again I provide a link for chess variant insiders like you: link to locally make SMIRF BC-168b available. As often repeated there also is an improved version for real donators. ;-) Best regards, Reinhard.

P.S.: could you please specify the PGN notation concerning your 10x8 extended castling rules? Because traditional O-O or O-O-O would not be always sufficient, as I presume.

Sam Trenholme wrote on Mon, Aug 13, 2007 03:57 PM UTC:Excellent ★★★★★
It saddens me to see that the excellent SMIRF chess variant engine is no longer available for download. Fortunatly, I was able to download a copy of SMIRF when it was still free downloadable, and have finally had a chance to give this chess engine a test spin. The variant I have SMIRF play is my own 'Schoolbook Chess' (CRC setup #27621 with different castling rules).

SMIRF has a very romantic style of play, making bold sacrifices. For example, in thie game against Zillions of Games, where both sides have five seconds to make a move on a Pentium Core Duo 1.5Ghz, SMIRF has the black pieces and makes several bold sacrifices before finally delivering the mating blow to white:

1. e4 Ng6 2. f3 Nd6 3. d3 Af6 4. NI3 e6 5. Ng4 Ah5 6. I4 AI6 7. Nb3 h5 8. Nc5 Qc8 9. Ixh5 Axh5 10. NI3 Af4 11. g3 Ah6 12. h3 b6 13. Ng4 Aj5 14. Nb3 Mh8 15. Af2 BI6 16. Bj4

SMIRF gets ready to make his first sacrifice.

16... Mh5!? 17. NI3 Mxj4 18. Nxj5 Bxj5 19. Ag1 Mh5 20. Kf2 Mg5 21. f4

SMIRF now sacrifices both of his knights to continue the attack on White's King.

21... Nxe4+! 22. dxe4 Mxe4+ 23. Kg2 Nxf4+! 24. gxf4 Mxf4+ 25. Kh2 KI8 26. c3+ f5 27. MI5

SMIRF sacrifces his bishop in order to keep his attack lively.

27... j6! 28. Mxj5 Qb7 29. Bf3 Qxf3 30. Axf3 Mxf3+ 31. Kg2 Mf4+ 32. Kh2

Black can now force mate; finding this mate is left as an exercise to the reader.

In another game, SMIRF plays ChessV, with SMIRF having the white pieces and each side given 30 seconds to decide their move on a Pentium Core Duo 1.5Ghz. Here is how that game went:

1. Ng3 e5 2. Mh3 Ne7 3. Nd3 Neg6 4. e3 d6 5. f4 exf4 6. exf4 Ad7 7. Af2 Axh3 8. Axh3 Ke8 9. Bg4 Bh4 10. Bd7+ Kd8 11. Qe1 Ne7 12. Bf2 Nhg6 13. Nf5 Bxf2 14. Kxf2 c6 15. Nxe7 Nxe7 16. Qe2 d5 17. Nc5 Ng6 18. Rje1 Kc7 19. Bxc6 Kxc6

At this point, even though White is down material, he can force mate. The mate, again, is left as an exercise for the reader.

Mark Thompson wrote on Mon, Aug 13, 2007 12:41 AM UTC:
Today in Germany a law forbidding vaguely-defined 'hacker tools' went into effect.


This is a real DEATHBLOW to computer-using German people, because it makes no distinction 'between, for example, a password cracker and a password recovery tool, or a utility designed to run denial of service attacks and one designed to stress-test a network.'

What may be worse, 'While making life more difficult for security consultants and sys admins, the new laws will, paradoxically, make it easier for police to use hacking tactics in gathering intelligence on suspects.'


Please try to avoid Germany's becoming a totalitarian country. Until this law is rescinded, I promise to drink no more Beck's--nothing but Heineken and Guinness. I hope you'll do the same.

💡📝Reinhard Scharnagl wrote on Sat, Aug 4, 2007 07:23 PM UTC:
A real DEATHBLOW to email contacts with US American people

Well, because I am not interested in having my email postings 'legally' verified by the CIA, NSA and other 'peace securing' organisations, even without finding any suspicion against my person, I will no longer correspond with people from USA by email. Please try to avoid the USA to become a totalitarian country. 

So please join boycotting that raising freedom killing USA practice. 


Stephen Stockman wrote on Thu, Sep 21, 2006 04:53 AM UTC:Excellent ★★★★★
u could be the lucky 12000'th visitor at my 4-way chess web-site

💡📝Reinhard Scharnagl wrote on Wed, Sep 20, 2006 05:36 PM UTC:
Hi Sam. Please note, that there is a rule number one (especially its second

1. the bishops have to be placed upon different colored squares; same rule
applies to the implicite bishop pieces: queen and archbishop (aligned to

A reader wrote on Wed, Sep 20, 2006 04:42 PM UTC:
Er, ..

'the queen is the the left of the queen.'

'the king is to the left of the king,'

This doesn't make sense !!

Sam Trenholme wrote on Wed, Sep 20, 2006 02:58 PM UTC:
OK, I've looked at the list and can sorta see why you had 12118 setups when I had 9820 setups. First of all, I consider mirror image setups to be identical, so I have removed them by requiring the queen to be left of the king (from white's side of the board) in all of my setups. This reduces the number of possible setups from 252,000 to 126,000. I note that you consider a setup and its mirror different--which it can be given certain castling rules.

I modified your list of crc setups to only show the ones where the queen is the the left of the king. For some reason, your list of 12118 setups has 6056 setups with the queen to the left of the king, and 6062 setups with the Queen to the right of the king.

Once I did this, I noted that there are some 3764 possible opening setups, where all the pawns are guarded, the king is to the left of the queen, and where there are no bishops together, that are not on your list of possible setups. I have put this list here:

This list uses 'M' for the rook + knight piece and 'A' for the knight + bishop piece.

- Sam

Edit: Fixed 'queen' and 'king' wording.

💡📝Reinhard Scharnagl wrote on Mon, Sep 18, 2006 10:01 PM UTC:
Hi Sam, here is a link to all those 12118 valid CRC arrays:

Which of them is not correct or doubled? Of course, I am not perfect, but
I need a precise hint if need be, if something really should be wrong.

Sam Trenholme wrote on Mon, Sep 18, 2006 05:51 PM UTC:
'There 12118 positions still are remaining'

My program counts 9819. Here are my restrictions:

* All pawns defended

* King between rooks

* No bishops together

* No RNBQMKABNR setup (patented; M = Rook + Knight; A = Bishop + Knight)

I'm curious where the number 12,118 comes from.

- Sam

💡📝Reinhard Scharnagl wrote on Fri, Apr 14, 2006 07:39 AM UTC:
There has been a question, why SMIRF is supporting two other castling
modes than merely the standard castling. Despite of that this is exceeding
genuine CRC questions, here is the answer: SMIRF also is supporting Janus
Chess, which needs 's' = symmetric castling, and MBC (Embassy), which
needs 'm' = modern castling.

CRC follows the traditioal approach to place the king after castlings
either two squares distant from alpha-side or one square from omega-side.

Derek Nalls wrote on Fri, Apr 14, 2006 06:02 AM UTC:
Out of the 3 options offerred for castling in SMIRF, I chose 'symmetric'
castling for Optimized Chess 8H x 10W.  This destroyed my plan to compare
the strengths of SMIRF and Gothic Vortex III at this game by letting them
fight it out at 3 minutes per move since the latter program exclusively
supports traditional or 'normal' castling as exists in Gothic Chess.

It is particularly gracious of Scharnagl to support symmetric castling
within SMIRF, esp. since he has stated clearly that he personally prefers
normal castling.  To date, I suspect that a good reason to prefer
symmetric castling has not been explained.

Any unique game is singular in nature, regardless of whether it exhibits
an east-west symmetry or asymmetry.  However, unlike E-W symmetrical games
which always exist as 1 unified, opening setup, E-W asymmetrical games are
split so they always exist irreducibly as 2 mirror-image opening setups
which can be transposed into one another.  Obviously, neither one is any
more or less proper than the other.  

Of course, most inventors only offer 1 of these 2 mirror-image, opening
setups as the asymmetrical game and most players, on the rare occasion
that a choice between 2 is offerred, will always prefer to learn using
just 1 of them.

Ideally, the king would be perfectly centered by E-W measure so that
castling would naturally be the same between the 'Mirror I' and 'Mirror
II' variants of Opti Chess.  Unfortunately, this is obviously impossible
as the '10W' in the game title gives a strong clue.  An odd, NOT even,
number of files must exist for it to be possible to perfectly center any
single piece E-W.

The opening setups in Mirror I and Mirror II have the 2 rooks balanced
perfectly, equidistantly, symmetrically E-W from the center of the board.

The opening setups in Mirror I and Mirror II have the king as close to the
exact E-W center of the board as possible which is unfortunately, the line
dividing the 5th and 6th files.  Consequently, the king rests on the 6th
file square in Mirror I and the 5th file square in Mirror II.

With normal castling, the king and rook will end-up on destination squares
that are asymmetrical from the exact E-W center of the board within both
variants AND on destination squares that are different when comparing both

With symmetric castling, the king and rook will end-up on destination
squares that are symmetrical and identical within and between both
variants.  Essentially, a simple average of the results of normal castling
for Mirror I & II is taken which yields whole numbers.  

By contrast, one can wonder (with dark humor) how the person(s) who
established the standard for normal castling kept from going crazy when
you realize ...

In deciding exactly where to drop the pieces kingside and queenside, in
turn, they had to decide whether it was more proper to round-off exactly
1/2 square's distance to zero square's distance or 1 square's distance.
Even Dr. Mark Thompson could not answer that one!

Derek Nalls wrote on Sun, Apr 9, 2006 03:00 AM UTC:
optimized chess 8H x 10W

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