Comments by JorgKnappen

I want to coment on the rule 'When stalemate wins, repetition of
positions
is forbidden'. This rule is known to Go players as Superko rule. Alltho
it is implemented in some official Go rule sets (e.g. for New Sealand) it
is considered problematic. The reason is that humans are not good in
tracing
repeated positions except in the most simple cases.

In my opinion the FIDE rules are perfectly right: One can claim draw on
repeated position, but there is no automatic consequence.

A superko rule theoretically rules out a draw (or in Go terms: a no
result),
but in chess there are just too many positions available to eliminate
draws
effectively in play between humans.

Nice summary.

I just want to add name and date for Janusschach:

It was invented by Werner Schöndorf in 1978.

Another game using this piece is my Quintessential Chess, designed 2002
for the 84 squares contest. I decided to use the name Janus for this
piece.

The game resembles much to Pillar Chess (described on this site)
and >>Das trojanische Spiel<< (commercial, german game, having a link
in the german section of this site).

I have considered the erl queen (as I prefer to call the slip queen),
but discarded it because it is off-theme: it can triangulate, what
a switching piece cannot.

I drafted the erl queen for the sweeping switchers, because there I
needed
a piece with the can-mate property.

This is an excellent pedagocical presentation of Ralph Betza's
funny notation as it is. Thanks to Glenn for this.

I am just designing a doucecimal chess variant (on a 12 times 12 board)
and wonder how many moves I should reserve for the modified 50 moves
rule. 

I think, there should be sufficient moves such that knight and bishop and
king still can mate a bare king. The number of moves theoretically needed
is surely known, has someone the numbers ready for different board sizes?

According to Cazaux's book on chess variants (in french) it
is a species of cat, latin name Panthera unica, french once.
Don't know german or english names.

--JKn

I don't know any better name for the slip bishop, nor do I know any game
or problem that uses this particular piece.

I have different sources to Grande Acedrex, suggesting that the Unicorn
of Grande Acedrex is really a bent rider and not the piece described in
the webpage on chessvariants.com 

--JKn

The excellent is for asking this really good question. I want to list these
favorites:

1. Chu Shogi A big shogi variant introducing lots of interesting pieces.
And it has a players' community as well (even organised and with
tournaments). 

2. Tai Shogi A very big shogi variant with pieces no westerner has even
dreamt about like the hook movers.

3. Sons of Mithra A chess variant with very much flavour in it. It has
creative pieces, creative methods of capturing, and the traces of sound
playtesting.

4. Seperate Realms Chess A good example of how a rather restrictive idea
leads to an excellent game.

5. Perfect 12 I love Cazaux' style in chessvariant design and this one is
a good example. Don't miss the other games by him!

Since you already found the Nachtmahr page, here is an explanation: In
order to move from b1 to e4, the Crooked Nightrider must contain the
diagonal narrow crooked nightrider. In order to checkmate the poor king
from e4 it must contain the straight narrow crooked nightrider. We cannot
conclude whether it contains more components from that little bit of
information, hence in a strict interpretation the two components mentioned
make up Betza's Crooked Nightrider.

The latter list features the Spiralspringer very well. Note the difference between german terminology and the terminology used here; what in german is called eng is called wide here, and what in german is called weit is called narrow here.

Note also, that Ralph Betza's Crooked Nightrider (combined narrow straight and diagonal crooked nightrider) is called Boa by problemists with the following reference given: R. Bedoni, Phé­nix (45) X 1996 S. 3344

A nice piece and a good name for it. Congrats!

Hey Sam, you just rediscovered the Rhino, have at look at the Piecoclopedia
entry for more information about this really nice piece:
http://www.chessvariants.org/piececlopedia.dir/rhino.html

In fact, mating with the mirror-rhino can be more complicated than mating with a simple FN, because
the additionaly attacked zebra square provides lot of stalemate traps. A key position in the mirror-rhino's mating manoeuvre is the following:

Black King on a1,a2,or b1; White king on c3, mirror-rhino on f6.  Black to move.

Only now the white king can complete the confinement of the black king

--- BTW, the rhino is not colourswitching at all, it is a slider continuing its way after WN squares to
C NN2 .... Adding the wazir to the Gnu essentially gives it the can-mate property.

This is a forward reference to X Chess by Jeremy Gabriel Good

http://www.chessvariants.org/index/msdisplay.php?itemid=MPxchess

where many pieces of Seenschach are set on another innovative hourglass shaped chessboard.

I am looking for a certain circular chess variant I have seen in the 1980s.
It was published in a physics students' journal (if I remember correctly
from Bochum) in germany. The board consisted of a full circular disk. The
'squares' in the innermost disk were triangular sectors. It used standard
chess pieces.

The most striking feature I still remember is that the bishop changes the
square colour while crossing the center. Does anyone know this variant?

The Teutonic Order did not have archchancellors. Their leaders are (they are still extant!) titled Hochmeister which is translated into english as grandmaster---not a name suited for a chess piece. The Holy Roman empire had three archchancellors, the most important of them was archchancellor of the germans. This post was filled by one of the 7 electors, the archbishop of Mainz. He was responsible (among other duties) for the organisation of the emperor's election and he substituted in emperor in the time of an interregnum (together with two vicars).

No, I have not been aware of the reference you mention, but now I know it and I shall build it into the notes when I revise the text.

The Rhino is an interesting and inspiring piece and this article is well written.

Correction: NW is emperor, prince is the NF in problemist's tradition.