Comments by Jörg Knappen

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.

This game should be judged by its design criteria: Given a set of pieces (in hardware), create a solid and playable chess variant for them. It think it fits this purpose well, allthough I think keeping the original movements of the Omega chess pieces makes this a rather slow game, because the pieces are short-range on a 12x12 board.

On the Omega wizard: A pair of wizards and a king cannot mate a lone king (on any conventional rightangular board). The reason is that they must switch between odd and even ranks and files all the time. On the big board the wizard is clearly weaker than the bishop; on 8x8 it may be equal or slightly stronger because of its higher mobility and forking power.

I agree with him on the value of the Eohippos. It is one pawn above the knight, giving it a value of 4. When I designed the game, I assumed that the value of the Chancellor or Marshall were equal to the value of the Queen. Taking the horizontal movent away should cost about two pawns leaving it with a value of 7. However, I don't think any longer that the equality of Chancellor and Queen holds true. There is something in the Queen making her a perfect chess piece and giving her a higher value than the comparable chancellor. So a realistic judgement of the Fischer's value lies between 6 and 6.5 pawn units---not enough to win against a rook in an otherwise equal setting.

In the setting against the fabolous FIDEs, the levelling effect or elephantiasis correction strikes the queen. This might still even the game.

So when I have to name a piece, I always look for an established name first. Often I find one I like and use it, sometimes I want to differ and choose another name.

I use the lists of Derzhanski, Jelliss, Grimbert and Poisson (in approximately this order of preference) along with notes I have taken from several chess variants. A new list is published by the problemist's journal Die Schwalbe, compiled by Gruber and can be found here: 

http://www.dieschwalbe.de/lexikon.htm

Truelove's list only gives names and games, unfortunately, and I have never done the task of annotating it with move patterns.

I do not use the names made up by Gilman for several reasons:

1. They are not based on exhaustive research, in particular they do not incorporate the four lists I have cited above. So he does not give the relevant names to known pieces and he sometimes assigns a new movement pattern to an already used name.

2. I need translatable names, i.e., names that work in languages other than english. Gilman's names rely heavily on untranslatable puns and anagrams.

3. For use in game notation, the initial letters should be different for the pieces drafted. Gilman's names tend to start in the same letter for many pieces.

There is a minor error about the WL (Wazir+Camel) compound: This piece cannot checkmate, because it does not control two orthogonally adjacent squares. Therefore it is not a major piece under the definition used by Fergus Duniho.

On the other hand, a Wazir and a Camel and a King (three pieces!) can mate a lone King.

Yes, it is. Currently I think that the Chancellor/Marshall is somewhat (maybe 0.5 pawn units) weaker than the Queen. The Fers move adds about 1.5 pawn units of strength, plus another 0.5 pawn units for curing the specific weakness of the Chancellor/Marshall, leaving the Archchanchellor at about 1.5 pawns stronger than the Queen. This difference should be noticeable during the game, but it is probably not enough to decide the pawnless endgame K+Archchancellor vs. K+Q in favour to the Archchancellor.

Note that this comparison is made for the 8x8 board. On larger boards the Queen gains strength compared to the Archchancellor because all her moves are long-range, but most of his moves are short-range.

The specific weakness of the Chancellor/Marshall is that the King can directly attack it. Thus adding a move-only Fers to it does not cure this weakness. But adding it may equalise the Chancellor with the Queen (on 8x8, of course).

The european invention of the queen was precedented by the Japanese invention of the 'Free King' in large Shogi variants (like Chu shogi) by some centuries. What is more striking in this context is that the european obsession since Carrera, namely the Chancellor/Marshall and the Janus/Paladin pieces, does not occur in asian chess variants. This says---IMO---something about the quality of the pieces: The Queen/Free King is a perfect chess piece while the other two leave something open.

Back to Eurasian chess: It has a nice piece and rule mix and makes a great variant (learning from several other excellent games). For my taste, the Eurasian pawn is a bit too complicated and the rules concerning the pawn could be simplified. Promotion to captured pieces only has an old-fashioned look, at least.

Formidable pieces, I say.

The Quintessence lacks the can-mate property on regular rectangular boards. The necessary piece of analysis goes as follows:

There is only one mating position with King and Quintessence vs. King, namely Black: King a1, White: King a3, Quintessence d2. Note that the position with a white King on b3 is a stalemate because the white King now blocks the check against the black King.

To force the the black King to a1, the position prior to the mate must look like Black King b1; White King a3, Quintessence controls squares c1 and c2. This can be done with Quintessence on b4 or d4. However, there is no quintessential move from b4 or d4 to d2. Therefore no mate can be forced.