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.

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.

First of all, the write-up of the rules is a bit too sketchy and a lot of interpretation is needed in order to bring this game to play.

Second, it is a straight and boring win for white under the following interpretation of the rules: If a piece is watched by a knight (friend or foe) it must move and this zugzwang cannot be lifted by capturing the knight unless the capturing move is also also executed by a piece forced by a knight.

The sample game starts as follows:

1. e3 e6 
2. d3 d6   The first two moves are forced. Taking double step
3. Na3 Nh6 Other black responses won't help either
4. c3 f6
5. Nb5     Now black must move the pawns on a7, c7, and d6 while
           white has three free moves. Afterwards, the knight moves
           to c7 pressuring Ra8, Ke8, e6. White has free moves again.
           Eventually white blocks a pawn and the game is over.           
           Alternatively, white can bring out its queen to checkmate the 
           black King.

A great idea and a great story together with the traces of playtesting. This makes an excellent new chessvariant.

Of course, a cooperative game can be regarded as a puzzle for one player only (fighting againts the dice), but my experience (from playing Rengo) shows that reading the partner's ideas adds another twist to a game.

A very interesting note worth reading again from time to time.

What makes me wonder here are the remarks about old shatranj and that
K+4F (same colour) should win against K+R. I tried this by hand and found no way of confirming this claim. 5 Ferzes of the same colour are a different thing: A chain of Ferzes along the long diagonal can confine the rook in one diagonal half of the board (with the help of the King and noting that it is forbidden to give permanent check in Shatranj). Then, the net of Ferzes can be tightened until the rook is caught in a net and can be taken by the King.

There is still considerable counterplay by an active defending King, and exact play is needed.

I think, the mentioned scenarioes are worth a computer analysis.

--Jörg Knappen

An excellent to this game!

Maybe the author has not read the comment below, otherwise he would have been frightened by the task he has underdone. On the other hand: Can a Spartan be frightened?

http://www.chessvariants.org/piececlopedia.dir/chess-different-pawns.html

--JKn

References

• Index of Ralph Betza's work on piece values
• A Pawn is as Strong as the Hand that Holds It Part I
• A Pawn is as Strong as the Hand that Holds It Part II
• A Pawn is as Strong as the Hand that Holds It Part III

Unfortunately, no one seems to know the circular chess variant I have
sketched in the previous message of this thread. The board was similar to
this one:

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

and the rules for going through the center were similar like in this
variant

http://www.chessvariants.org/shape.dir/globe.html

First, look at the recognised chess variants here:

http://www.chessvariants.org/rindex.html

Then, all national chess variants with a player community and some
tradition; i.e., Makruk, Sittuyin, Shatar (Mongolian Chess).

You may also look at contest-winning chess variants and contest finalists,
see here:
http://www.chessvariants.org/index/mainquery.php?type=Contest&orderby=LinkText&displayauthor=1&displayinventor=1&usethisheading=Contests

Unfortunately, Ibis is a well established and published name for the (1,5)-leaper, see e.g., here:

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

We tacitly assume that strength can be measured by one number and that the numbers can be compared using a transitive relation like 'greater than'. However, this needs not to be true, see here for a simple game with dice:

http://en.wikipedia.org/wiki/Nontransitive_dice

So here is a new chess variant challenge: Chess with nontransitive armies

Design a chess variant with different armies such that, whatever army your opponent chooses first, you can choose another army having an advantage over your opponent's army. (To avoid the first move problem assume 2 games where either army moves first once)

Charles,

I will not ask you to assign the name Ibis to the Zemel (we can live with multiple names for the same piece), but IMO you should consider giving the (1,8)-leaper another name.

Fergus,

you underestimate the strength of the fairy problemist's community very much. Fairy chess problem do not only occur in the mentioned journals (note that I posted recently a list of fairy pieces and fairy conditions hosted by Die Schwalbe); they are even included in FIDE albums (where you can earn points for becoming a chess problem grandmaster).

And there are lots of active composers for fairy problems around, they are creative with new pieces (like the Zabel pawn), and they are younger than Dawson :-)

If you are really interested in chess problems, the language of the journal is a minor issue: The diagrams speak for themselves and the conditions or special pieces use some standardised notation. The journals or problem books often have bilingual or trilingual glossaries.

I vote for the cat, alltho the other images are also good.

Great work! You should submit your package also to CTAN; 

http://www.ctan.org

there are some more chess-related TeX and LaTeX packages (and as a bonus, a Go package), but they don't handle chess variants AFAIK. (Chinese Chess is there; Shogi is missing on CTAN).

In fact, a bishop limited to 3 steps can be found in Taikyoku Shogi (The
monster version) under the name Rikishi (Wrestler). On the other hand, a
piece named Rikishi or Wrestler with different moves occurs in Tai Shogi
and Maka Dai Dai Shogi: Here it is a limited bishop who can move also one
square horizontally. In Ko Shogi, the Rikishi or Wrestler is lion mover. So
sticking to Bishop's Dog for the limited bishop is probably the best
choice.

This also gives me the opportunity to advertise Derzhanski's list again:

 http://www.chessvariants.org/piececlopedia.dir/whos-who-on-8x8.html

The huge advantage of this list that you can actually find pieces when you
know how they move; either
by searching the move notation or by estimating their strength and scanning
the appropriate strength region.

First, an excellent to the 2 new pieces, the knave and debtor. The two are nice findings and worth the consideration of other chess variant authors as well.

It is not an excellent for the whole game, because I think board design, piece mix and rule setup don't work as well as they could. For most pieces, 10x10 is already a too large board making them slow. The standard chess bishop and queen aren't good counterparts to knave and debtor. The standard chess rules on stalemate also don't accomodate knaves and debtors well: How many of them do you need to force the checkmate of a lone king?

Knave and debtor have a strong 'shatranjian' feel; probably a very good variant is taking standard shatranj and replacing the knights with knaves and the alfils with debtors. Note that the original shatranj has only 2 alfils (where 8 are needed to cover the whole board); in the same manner shatranj with knaves and debtors has only two of each species. In shatranj, stalemate and lone king are wins, which reduces the number of draws.

Hi Charles, I think the knave and debtor pieces are worth more thought and some playtesting, too. I currently think of publishing 'Knavish Shatranj' as outlined in my first comment as a game with your pieces. You and the others around here may come up with more games featuring knave and debtor.

A very inspiring game!

P.S. Thinking about the knave rotated 45 degrees ... a left-right asymmetric piece with camel and alfil moves, colourbound and knavish bound at the same time.

@Christine: Unfortunately, I do not even own an operating system necessary to run Zillions of Games; therefore I cannot make and test zrf files. 

@Charles: Yes, replacing Knights and Alfils with Crabs and Alibabas should make another army for Shatranj with different armies. Now waiting for more radical approaches touching the rook and the wazir, too.

Nice to see you back again!

I am updating the rating to excellent, because seeing the elegance of the knave and debtor pieces is obviously a non-trivial task. In fact, Abdul-Rahman Sibahi and Joe Joyce discussed the pieces (without naming them) here briefly

http://www.chessvariants.org/index/listcomments.php?itemid=MPcomplementarit

but they didn't see that they are exceptional. Perhaps it needs some hexagonal thinking to see it.

@charles: ... but can the rhino and the king force this position?

Yes they can, and they can do so easily: Essentially, after forcing the opposite king to the edge of the board, the rhino pushes forward using the wazir move.

A maybe funny question:

What happens to a pawn when it is converted into an undead piece? Say, a white undead bishop attacks a black pawn: Does the black pawn turn into an undead white pawn or does it turn into an undead black pawn under white's control? The difference between the two is the inherited directionality: By becoming an undead white pawn the black pawn turns 180 degrees and marches against his old camp; while an undead black pawn under white's control continues to march against the white camp (and may block white pawns in their progress).

Another question: 

Can an undead piece attack a life piece of its own camp? Because this action may strengthen the piece by taking its life it might be a favourable move.

Patzer has definitely german relations, there is the verb 'verpatzen' in
german, meaning to crab, to mull, to fluff, to foozle, to snafu. I don't
know its further etymology, it is quite possible that it is either yiddish
oder rotwelsch.

David, that's a aice X-mas present for all of us!

There is one minor poiint I want to correct (it is not your fault; already Jeliss has this particular sentence wrong):

>null piece (Exotic): n. Piece that, combined with any other piece leaves it unaltered = Dummy = (0,0) leaper. Not the same as zero. Link(s): All the King's Men. [index] Source(s): [ATKM] Unique ID: [CVT-10825]

A dummy is a piece without any move; as a leaper it is an \emptyset-leaper, not a (0,0)-leaper. A (0,0)-leaper has one move to its starting square, essentially the piece-bound licence to pass a move.

This is always confounding to see that zero is something different from the emptyset.

The only measure to get solid information about the strength of a certain piece is to playtest it (in human play and/or computer play). As far as I know, there are few divergent pieces really tested.

Mike Nelson's Seperate Realms Rook comes out on a value of about 75% Rook plus 25% Dabbabarider, suggesting that capture constitues about 3/4 of the piece value, while moving alone constitutes about 25%. But this particular piece has rather similar move and capture patterns; the more the patterns diverge, the more playtesting is needed, and there is probably no simple formula describing the results.

Note also that the results of playtesting depend on the testbed: What board is choosen, what is the oppenent's army, what pieces are in the same army (sociability effects).

Some time ago, either in a published CV or in a discussion a new piece type
called 'area mover' or 'areal mover' was proposed here. It was kind of
a lame hook mover (known from large Shogi variants): It only could perform
a hook move when the whole area (defined as the rightangle spanned by the
two orthogonal rook moves) was free of intervening pieces.

I tried to google the reference, but it wasn't indexed.

Can someone remember the reference to this kind of piece?

I have an answer to your 2nd question:

The R3 is named Kongo (Guardian of Gods) in Taikyoku Shogi.

There's also a B3, named Rikishi (Wrestler) in Taikyoku Shogi.

Note that the Taikyoku Shogi pieces move differently then pieces with the
same name in other larger Shogi variants.

Here's a first pack of additions, all from the following new source:


George Jelliss: Theory of Moves, Knight's Tour Notes 2001,
http://www.ktn.freeuk.com/9a.htm

Notes are mine and introduced by the tag Note:

Piece Names

caliph  - compound leaper (0,1)+(2,2)
          Note: This is different from Charles Gilman's caliph
          Note: synonyms are waffle (CwdA) and phoenix (large Shogi variants)

diamond - compound leaper (1,1)+(0,2)
          Note: synonyms for this piece are duke and kylin

emperor - compound leaper (0,1)+(1,2)
          Note: a synonym is marquis (Derzhanski's list drawing from Adrian  King)

ferfil - compound leaper (1,1)+(2,2)
         Note: most established synonym on the CVP is 'modern elephant'

frog - compound leaper (1,1)+(0,3). The simplest amphibian.

hospitaler - compound leaper (1,2)+(2,2)

prince - compound leaper (1,1)+(1,2)

pterodactyl - compound leaper (3,3)+(5,5)+(0,15). The simplest triple range amphibian
    Note: I love this piece *because* it is so 'over the top'

templar - compound leaper (0,2)+(1,2)

wazaba - compound leaper (0,1)+(0,2)
         Note: synonym woody rook (CwdA)

Piece terms

amphibian - A compound leaper who can reach any square on the chess board whose components aren't free leapers 

free leaper - A leaper that can reach any square on a given board. On the standard 8x8 board there are 5 free leapers: wazir, knight, giraffe, zebra, and antelope.

The lore apprentice (Zauberlehrling) of Lines of Relay is an offshot of the querquisite, I conceived it by misunderstanding its moves. See

http://www.chessvariants.org/index/msdisplay.php?itemid=MSlinesofrelay%28l

I am aware of the name Okapi for about a decade when I found it in several problem databases on fairy chess problems. However, a search here

http://www.softdecc.com/pdb/search.pdb

(enter PIECE='Okapi' in the query form)

reveals some problems going back to 1970, Most Okapi problems are authored by Erich Bartels, but other prblemists joined the crew. If you have ever seen an okapi (I did, the Franfurt/Main zoo is a proud owner of the rare species), it is a particulary well choosen name for a horse-zebra vompound.

Digging through references on Gazelle, I found it only as a synonym for Camel (the (1,3).-leaper) in Turkish great chess V

http://www.chessvariants.com/large.dir/greatchessv.html

This is confirmed by George Duke here:

http://www.chessvariants.com/large.dir/falconpatent.html

and George know more chess variant literature than I can ever dream of.

The Ferz-Knight compound has the synonym priest - again a very unspecific name. It occurs in Töws' Generic chess piece creation system and Derzhanski's list.

I once aggressively tracked names for compound leapers and noted them on paper, it looks like a good idea to put them on the CVP pages some time.