Fairy Classification: preliminary questions

If the project of creating some better database of fairy elements might succeed? If we’re ready to jump into it? Who would be ready to join the team? What is the order and what’s the freedom? And what’s is the main purpose of this database?

Let me quote the words of Chris Tylor’s comment which has just appeared: “I now propose that we go back to basics and make the overall aim of our new database not so much to produce order as to give light – to show users new properties and applications of a range of fairy elements, together with the way in which they relate to other elements (or perhaps stand alone), and maybe in the process point users to ways in which new advances might be made.”  – Agree!

Let’s summarize the most important ideas from about 80 comments to Fairy Statistics post:

1. Statistics about fairy elements

2. INTRO to the classification: questions to the definitions of the classes, by Dmitri Turevski

3. Preliminary Classification, suggestions by Chris Tylor and Shankar Ram

4. Sources of information for classification and definitions

If we’re getting into this project, from the moment when the new database appears and has some entries I can start presenting it on JF. So, it might get in use before the whole project might be considered as finished or being up to date 🙂

For now I’ve created a GoogleSheet document Fairy-Classification for online work. The statistics and preliminary classification groups already included for future correction. I’d like to ask Shankar Ram to accept my invitation to be the main moderator of this project. The right to view/edit the document will be granted to all members of the team.

Welcome to join the project!

Your comments and updates are highly appreciated!


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shankar ram
shankar ram
October 26, 2020 02:34

Julia,
A journey of a thousand miles begins with a single step“. And I congratulate you on taking it!
Suggest we call it “The Fairy Chess Taxonomy Project“. (See also)
Of course, I accept your invitation with thanks!

Some additions to the sources:
http://problem64.beda.cz/silo/dawson_caissaswildroses_1935.pdf – TRD’s 1st book in his Caissa series, introducing various elements present at the time
http://problem64.beda.cz/silo/dickins_a_guide_to_fairy_chess_1971.pdf – A Pdf of A.S.M.Dickins’ pioneering work
https://www.dieschwalbe.de/lexikon.htm – Hans Gruber’s great labour of love! Updated till 26-Jul-2020.
http://problem64.beda.cz/silo/dickins_short_history_of_fairy_chess_1975.pdf – Some history

Last edited 1 month ago by shankar ram
shankar ram
shankar ram
October 26, 2020 06:46

I will attempt to answer Dmitri’s questions:
What is a fairy?
A fairy is any set of aims, ways, pieces, conditions and boards that differ from the current set used in the game.
What is a stipulation?
A stipulation is a combination of an aim and the way of achieving it.
What is a condition and what is a piece?
A condition is the set of rules, restrictions and limitations applicable during the play in a game, end game study or problem. The current set of rules, regulations and limitations used in the current definition of the game is assumed to apply and only those that differ are mentioned in the definition of a condition.
A piece is an entity that occupies a square in a chess board and is able to move to other squares, capture other pieces and also change its nature(e.g: pawn promotion). The way it does all these is clearly defined.

Borderline and other cases:

  • SingleBox: Since it is not in the current set of game rules, it is a fairy.
  • HelpSelfmate with final s#2 ( instead of s#1): This would be a new stipulation.
  • Reflex: Can be considered both as a combination of a stipulation(s#) and a condition(both sides must #1 if possible) or as a stipulation in its own right.
  • Series movers: Can be considered as a stipulation(one of the sides moves continuously to reach a position fulfilling the aim) or as a condition where one side passes till the last move.
  • Imitator(piece or condition?): This is a well discussed borderline case! I don’t think any final consensus was reached.
Last edited 1 month ago by shankar ram
Dmitri Turevski
Dmitri Turevski
October 26, 2020 10:30
Reply to  shankar ram

1a) So selfmates are genuinely fairy by this definition. This is fine, but it radically differs from the current classification used in WCCI, WCCT & FIDE Albums.
1b) What is current rules? FIDE rules of chess? There may be a problem with that: these rules are constantly changing (and problemists have no government over that), does it mean fairy classification is expected to be amended retrospectively?
2) This is so vague that its practical usefulness is really questionable. This vagueness had prevented you from having a definite answer regarding the series/reflex. I would really recommend digging up the old MP threads with the mathematically beautiful approach to stipulations by Kevin and Petko. The core idea is that there are only two ‘ways’ – direct and help (that is against best/worst defense), but any valid substipulation can be an ‘aim’ in its own right, all the rest are conditions. Helpselfmates are obvious, less obvious may be that #2 is in fact direct-(direct-#-in1)-in1 – that is exactly how the solving programs handle it internally leaving no place for ambiguity!
3) A dummy is not a fairy piece by this definition which is somewhat counter-intuitive. On the other hand, if only occupying a square and having a definite behavior are required then holes and magic squares would become pieces.

Dmitri Turevski
Dmitri Turevski
October 27, 2020 05:51
Reply to  Julia

The wikipedia link above educates us that the taxonomy is also about the study of the underlying principles.

Of course the WFCC rules are not cast in stone, the question is where have they gone wrong? Shankar Ram suggests (if I understood his answers correctly) that selfmates should be classified as fairy (the aim to mate own king differs from that in a game). Vlaicu, on the contrary, suggested that helpselfmates should not be classified as fairies (and he’s not alone in this).

I’ve simply brought up the underlying principle (fairy = legality of moves differs from that in a game) that supports Vlaicu’s suggestion. It was not about battling at all.

Similar arguments can be made as to why the Reflex is a condition (not very different from the Maximummer) and dummy is a piece and neither is a borderline case.

shankar ram
shankar ram
October 27, 2020 17:38

Dmitri,
Will reply in more detail later.

For now:

I remembered a third way of defining a Reflexmate: W & B play in opposition to reach a position where they can h#1. This seems to be sufficient. No additional condition like “should #1 if possible”. The moment a h#1 position is reached, the contract is met. Of course, there’s no need to muddy the waters further by adding this definition here!

Selfmates and Helpmates are in separate sections in FA, WCCT, WCCI, World Cup, YCCC, Olympic as also in most columns due to historical/convenience/familiarity/popularity/volume/judging/etc. reasons. Not because they are inherently “non-fairy”. I think the term “Heterodox” used by Vlaicu in his post may refer to such cases which are not orthodox, but have become so familiar that it seems strange to call them fairies.

Last edited 1 month ago by shankar ram
Dmitri Turevski
Dmitri Turevski
October 28, 2020 08:45
Reply to  shankar ram

That’s very interesting, thanks, I believe I did not know this one!
However, that’s not exactly a “h#1”, it’s a “h#1 Half-duplex” – that is, other side is to fulfill the stipulation from that point. This could be an important difference.

shankar ram
shankar ram
October 28, 2020 09:57

How so? For example, in a r#2, there are 4 plies: W1/B1/W2/B2. After the key, after any B1, the position is a h#1 for W. Similarly, in a genuine reflex try, only 3 plies are required: W1/B1/W2 and the position after W1 is a h#1 for B.

Dmitri Turevski
Dmitri Turevski
October 28, 2020 13:05
Reply to  shankar ram

That’s exactly my point.
h#1 stands for helpmate in one. “A helpmate is a type of chess problem in which both sides cooperate in order to achieve the goal of checkmating Black” (this is from Wikipedia, but similar definition can be found in virtually any other source).
Therefore, a type of problem where both sides cooperate to checkmate White is not a helpmate.
It may be called “a h#1 for W”, however, “h#1 half-duplex” sounds more conventional to me, as that’s how it is recognised by Popeye for example (Stipulation h#1 Option HalfDuplex).
It’s a nice and subtle trick though 🙂

shankar ram
shankar ram
October 28, 2020 18:40

…where they can h#1“. “They” = W or B. So the mated side can be B or W. That’s my interpretation. But I agree it may not stand scrutiny!

Dmitri Turevski
Dmitri Turevski
October 28, 2020 14:22
Reply to  shankar ram

It also seems that “W & B play in opposition to reach a position where they can h#1 [for W]” w/o additional conditions only works for semi-r#
In opposition play black defend not by not letting white to reach the aim, reaching the same aim themselves achieves them nothing. In a reflexmate black defends because white is forced to mate and checkmate ends the game. In the above definition nothing forces white to checkmate after 1. W1? B1!

This can be more easily understood if we change the aim from checkmate, to “reach a certain square”, for example.
Black cannot defend by reaching this square themselves first! White is still might be able to reach the aim after that.

nicolas dupont
nicolas dupont
October 28, 2020 15:48

Yes, r# is double-face. The semi-r# is a “normal” stipulation/goal and there is a (white) reflex in addition. Note that this additional condition can be defined for other stipulations, even for proof games, as shown in 1257.
Hence it looks like the basic stipulation is semi-reflex, and reflex should be handled as a condition which apply to (almost) different kinds of stipulation. Saying otherwise r# should not be classified as a stipulation, but as a mixed stipulation “semi-r#” and condition “white reflex”.
On the other side r# is not fairy to my mind, just because each solution under this genre is a valid ending of an OTB game (ending because the diagram position is generally not the initial position of the chess game).
The case where the goal is not checkmate/stalemate is interesting. It is always classified fairy, whatever is the stipulation, and I agree with that. Indeed a solution where the goal is not such a terminal move does not correspond to a valid ending of an OTB game. To my eyes this is the right method to classify the fairy/not fairy genres. 

Dmitri Turevski
Dmitri Turevski
October 28, 2020 21:22
Reply to  nicolas dupont

On the other side r# is not fairy to my mind, just because each solution under this genre is a valid ending of an OTB game

This would also be true for Maximummer.

nicolas dupont
nicolas dupont
October 28, 2020 22:12

Yes indeed, mainly because checks are orthodox and parrying a check too in Maximummer (unlike eg Monochromatic). But it doesn’t really matter for fairy/not fairy classification I think, because it is a condition and not a stipulation/aim. Each condition might be considered fairy even if no illegal orthodox moves are allowed (Maximummer is just a particular choice in the set of orthodox legal moves).
A funny thing is that, if one follow my own taste, reflex defined as a stipulation is not fairy, but reflex defined as the stipulation “semi-r” plus condition “white reflex” (my favorite approach), becomes fairy! Btw semi-r is a bad name to my mind because there is by no way something reflex in it.

Dmitri Turevski
Dmitri Turevski
October 28, 2020 23:45
Reply to  nicolas dupont

Is there such a thing as a non-fairy condition? I would assume no, but I’m open for ideas. (What is a condition? Alteration of the rules?)

I believe “reflex” in semi-reflex stands for black acting upon their reflexes: see prey – snatch prey, see checkmate – go for it. That sort of analogy. Can be semi if White refrains 🙂

nicolas dupont
nicolas dupont
October 29, 2020 01:21

“Is there such a thing as a non-fairy condition?”
Is there such a thing as a non-fairy piece, except the usual ones?  
For example one can define (if not already done) a “maximummer piece” – an orthodox piece with restricted legal moves. Each sequence involving maximummer piece(s) would be a legal orthodox sequence, but probably such a piece should nevertheless be considered fairy.

Dmitri Turevski
Dmitri Turevski
October 28, 2020 22:03
Reply to  nicolas dupont

white Ka1 Pa2
black Kc1 Sb3
how many last moves?
a) orthodox b) semi-reflex

nicolas dupont
nicolas dupont
October 28, 2020 22:35

Yes I see your point ha ha! -1 Sd4-b3+ is orthodox legal but semi-reflex illegal as black should have played -1 Sd4-c2# You’re right there is a slight difference between “being able to checkmate” in help-play and “being forced to checkmate” in semi-reflex.

Dmitri Turevski
Dmitri Turevski
October 29, 2020 01:00
Reply to  nicolas dupont

Yep, that was the point. But mustn’t the last move have been a capture?

shankar ram
shankar ram
October 28, 2020 18:47

But in a Reflex-[reach square xy] stipulation, W tries to make B occupy that square, and B does likewise?

nicolas dupont
nicolas dupont
October 28, 2020 20:06
Reply to  shankar ram

Yes, W tries to make B occupy that square, and B is defending except at its last ply. But B has 2 ways to defend. First to go far away from the goaled square (this is the semi-r part) and second to give white the opportunity to reach that square firstly (this is the white reflex part). In such a case white is obliged to reach the goal and the game is over. So the defense is successful because the true goal (B occupy that square) is not fulfilled.
As an example consider :
B: Ka6 W: Ba5 Sd6
r(b8)2
If white is playing eg 1.Sc4 black is escaping 1… Kb5. The key is 1.Bd8! Then 1…Ka7 is forced and black may reach square b8 at its second ply. This is the semi-r face.
The second face (white reflex) makes 1.Bc7? a wrong key. Indeed 1…Ka7 is still forced, but then white is forced to play 2.Bb8 (reflex move) and the game is over, so black is unable to reach the goal at its turn with 2…Kxb8.
The most important point is “and the game is over”. It is missed in the classical definition of an r# because redundant (black is unable to checkmate if it is checkmated by itself). But when the goal is not terminal, it is important to keep this rule in mind (and to mention it clearly once the reflex definition will be included in this workshop!). 

Dmitri Turevski
Dmitri Turevski
October 28, 2020 21:19
Reply to  nicolas dupont

But when the goal is not terminal, it is important to keep this rule in mind

Exactly! “Reach h#1 position” is not a terminal goal. So, if reflex is defined via h#1, this additional rule needs to be stipulated.

shankar ram
shankar ram
November 16, 2020 08:56

Chris Taylor has unearthed the following problem from the early days of JF:
https://juliasfairies.com/problems/page-17/#No.41. No. 42 by Zoran Janev.

DIRECT-HELPMATE (dh#)
White moves first, and black defendes himself, until the last move, when black and white play h#1.

This is closely related to the definition of a R# being discussed in this thread.
R#: W & B play in opposition to reach position where W can h#1
Dh#: W & B play in opposition to reach position where B can h#1
Of course, in a R# W is obliged to #1 if possible. But in the Dh# analogously, W should h#1 if possible, which is not mentioned in the author’s definition.

shankar ram
shankar ram
November 16, 2020 13:30
Reply to  shankar ram

But appears to have a cook 1.Ba3 c2 2.Bb2#
And short length duals 1.Bb4 ~ 2.Bxc3#
If we interpret as above. Maybe the author’s intention was a Dh EXACT#3!

Nikola Predrag
Nikola Predrag
November 16, 2020 16:10
Reply to  shankar ram

Zoran’s intention seems pretty clear from the author’s solution. But in the given definition, “until the last move”, might be puzzling.
dh(n)# means that Black would help ONLY by his last move before/preceding the n-th white move.
White is allowed to mate before n-th move but Black opposes by his first n-2 moves.
So 1.Lb4 indeed threatens 2.Lxc3#. Unfortunately, a short threat disables hypothetical possibilities of defence that would be specific for such stipulation – defending against h#1.5.
The try illustrates this:
1.La3? threatens h#1.5 – 2.Lc1(tempo) c2 3.Lb2# (obviously not the usual h# numbering of the moves) but 1.Lb~ refutes (by check). A defence against that threat is 1…e4 2.Lb4! Lf8 3.Lxc3#
There’s an antidual in the solution, due to a pin: 1.Lb4! e4 2.Ka3(tempo)? Lf8(?) 3.Lxc3???

Last edited 13 days ago by Nikola Predrag
Dmitri Turevski
Dmitri Turevski
November 17, 2020 06:36
Reply to  shankar ram

I agree, the intention clearly was something like Direct-(h#1)-in-exact-2.
“until the last move” should have been stipulated “until the (n-1)th move”.

shankar ram
shankar ram
October 27, 2020 18:00
Reply to  Julia

Amen to that, Julia!
Tamaso ma jyotir gamaya

Marjan Kovačević
Marjan Kovačević
October 27, 2020 20:25
Reply to  shankar ram

Shankar, your comments already bring some light! And smile!

Dmitri Turevski
Dmitri Turevski
October 26, 2020 12:32
Reply to  shankar ram

Some moves that are perfectly legal in an OTB game are illegal in r#.
Some moves (pass) that are absolutely illegal OTB are legal in seriesmovers.
Nothing of this kind happens in s# (the set of legal moves is always the same as in an OTB game).

There may be a pattern here 🙂

Coincidently(?), the WFCC puts the ser- and r# into fairies, but the s# separately.

Joost
Joost
October 26, 2020 08:21

One important thing should be considered: Interaction between stipulations, aims and conditions. Some combinations (e.g. Maximummer and reflex-mate: The reflex stipulation is ‘stronger’ than the maximummer condition; or circe+take&make: Which should be done first? The make-move or the rebirth? There are cases where the order is important; Anticirce + locust: For file-based rebirths (pawns, fairy pieces): Is the rebirth on the file of the capture or on the file where the locust arrives?) require a description of how the two elements interact.

Last edited 1 month ago by Joost de Heer
shankar ram
shankar ram
October 26, 2020 10:35
Reply to  Joost

Most combinations do not involve interactions, luckily! In the few that do, any ambiguity that exists, like the ones you mentioned, needs to cleared up. These have to be considered as special cases in our classification. We have to avoid further increase of fairy forms like “WinChloe version”, “Popeye version”, “type A”, “type B”, etc.

Georgy Evseev
Georgy Evseev
October 26, 2020 14:07
Reply to  shankar ram

Unfortunately, when such interaction exists we generally have a branching combinations. Sometimes it is just the order of conditions matter, sometimes it is the issue of interpretation. My favourite example is neutral pieces+Madrasi. The current common interpretation is based on the article by Petko Petkov, but it is not the only possible one. At the same time, it is impossible to propose another interpretation now, as the current one has become kind of “classic”.
Some issues even does not require interaction, for example: is zero-move allowed when it involves real movement (e.g. Rose or cylinders), etc.

Dirk Borst
Dirk Borst
October 26, 2020 10:20

This sounds like a very interesting and important project.How can I join in?

Maryan Kerhuel
Maryan Kerhuel
November 16, 2020 17:27

I would like to join the team working on the fairy classification

shankar ram
shankar ram
November 16, 2020 19:41
Reply to  Maryan Kerhuel

Maryan,
You need to create a Gmail ID and send it to Julia