Comments/Ratings for a Single Item

Note that there is no indication whatsoever that the first step of the Grant-Acedrex N-then-B would be non-capturing in the Alfonso codex. This just states (after describing the real-life animal as a Rhino):

First, like leaps like a knight. It may remain on
that square if it wishes or may also continue to any square on the diagonal(s) of that square,
maintaining its movement in a forward direction from that square

I don't know where Betza got the idea (which he then himself rejects) that the piece could have been divergent.

Given that the game had no Knights, leaving the piece vulnerable to Knight attacks would not have been important. But making its Knight move non-capturing would leave it vulnerable to all of the Gryphon's moves. It would also diminish its usefulness for defense, which would help make the game more decisive. Since the Gryphon is the most powerful piece in the game, there is less need to diminish its usefulness for defense. After all, it is the main piece that a player will use for offense if it is available. But if the Unicorn could capture with its Knight move, there would be more tempatation to use it defensively, and that could make the game more drawish. So, I think that Gryphon/Unicorn is a better choice for a game than the other two pieces used together.

Indeed. The W-then-R and F-then-B would have overlapping paths, which could be considered a design flaw.

All these pieces have a leap followed by sliding. Of course there also are the 'hook movers' of the large Shogi variants, which have both legs of their move a slide, which makes them immensely powerful.

In the same place was described a piece called the Unicorn, moving as Knight then Bishop. Supposedly the Unicorn couldn't make a capture using its Knight move, but I'll ignore that silly rule.

Not described there is a piece which makes a one step Rook move and then continues outwards as a Bishop. For lack of a name, I'll call it the Aanca (13th century Spanish for "Gryphon"). Although the Aanca is not described, one can suppose that the same mind who conceived the Gryphon and the Unicorn probably also considered the Aanca.

I don't know if Betza ever visualized movement diagrams for these pieces. Assuming non-overlapping paths of movement, the Unicorn covers most of the same spaces as what he calls an Aanca. One of the main differences between them is that the Unicorn cannot attack any of the same spaces as a Gryphon, whereas the Aanca and the Gryphon can both attack the same spaces as a Knight. This would have been an intelligent design choice, and not a silly rule, for the following reasons:

• It makes the Gryphon and the Unicorn complementary like the Rook and Bishop are.
• It gives the Unicorn greater mobility in tight spots, which could increase it's usefulness in the midgame.
• It leaves the piece vulnerable to the Knight and keeps it from forking pieces like a Knight.

So, it seems likely that the designer did consider the "Aanca" and for the reasons I gave, rejected it in favor of the Unicorn.

Likewise, the Gryphon and what might be called the Hippogriff cover nearly the same spaces under the assumption of no overlapping paths. So that paths don't overlap, its orthogonal move could continue only in the direction of the longer part of the Knight leap. Like the Unicorn, the Hippogriff would have more mobility in tight spots, and its short-range attacking power would be crippled. If it were allowed overlapping paths, it would be a monster piece that could force checkmate against a long King, because it could attack adjacent ranks or files.

To prevent confusion it is probably best to drop the name Aanca from English completely. We could have:

• F-then-R: Griffon
• N-then-R: Hippogriff
• W-then-B: Antigriff
• N-then-B: Monoceros

There are some other possibilities with 90-degree bends:

• W-then-R: Ultragriff, the logical extension of the series Hippogriff -> Griffon -> Ultragriff
• F-then-B: Chirogriff. (Entirely new move pattern, chimera of a Bat (Chiroptera) and a Lion, with claws at the tip of its wings.)

Logically the degenerate cases (which make a 0-degree bend) also belong in this class

• D-then-R: Ski-Rook
• A-then-B: Ski-Bishop

I think I have to revise the spelling in Apothecary Chess Modern then for both Griffin and Aanca!

So, Ancaa (or Anqa) is not really another word for Gryphon (or Eagle for that matter), but a mythological creature with no parallel to a mythological creature known to English speakers. This would make sense, given that mythological creatures are made up, and different cultures are unlikely to have the same ones. It's sort of like translating the Korean Gumiho (nine-tailed fox) as a werewolf or the Japanese Oni as a demon. In that case, I don't object to using each name for a different piece. It's just a bit awkward that Betza lifted the name from the Spanish name of a piece he was using the English name for with the description given for it.

Jean-Louis will probably be able to say more on this, but new translations of the Alfonso Codex have created a sort of consensus that Murphy was indeed completely wrong, and that the 'Unicorno' piece is an N-then-B. It depends a little bit on the interpretation of 'forward', whether this means "in the direction of the promotion rank" or "outward". The manuscript also contains descriptions of the real-life animals on which the pieces are modelled. And from this it is obvious that it is intended to depict a Rhino, even though the illustrator of the manuscript obviously had never seen one in his life, and hasd no clue as to how it looks. The move is supposed to reflect the behavior of the real-life animal, "starting with a leap, and then charging forward in a straight line". That doesn't suggest a reversal of direction after the leap; no real-life Rhino would be agile enough to do that. So it is pretty certain that 'forward' meant 'outward'.

@Greg: Interesting list. One thing I noticed is that it says

Anqa (Arabian) - Legendary Huge Satanic Eagle with Human Face. sometimes can resurrect herself like phoenix did.

So accoding to this Aanca is not Spanish for the mythical Elephant-eating bird, which was called 'Roc' in Arabic, but an Arabian name itself for an entirely different beast. And this latter beast is actually very close to what in Greek / Roman mythology is called a Harpy. This suggest the correct the correct translation for Aanca is Harpy.

[Edit] I looked up the translation of the Alfonso Codex, and from the description of the Aanca is is obvious that this is the Elephant-eating bird. So so much for the accuracy of the list... This is the quote of the translation of the Unicorno description:

The rhinoceros is a very large and very strong beast with two horns – one on its forehead and
one on its nose. Its nose horn is so strong that it can spear an elephant in the gut and lift it from
the ground. The forehead horn is very sharp and cuts powerfully. This rhinoceros is as large as
an elephant and ash coloured. It has ears like a pig and when it is angry its eyes turn as red as
ruby. When it begins to run it runs far after it gives a jump like a horse and so does its piece. The
rhino’s move is composed of two different steps. First, like leaps like a knight. It may remain on
that square if it wishes or may also continue to any square on the diagonal(s) of that square,
maintaining its movement in a forward direction from that square.

I remember having looked at the original text, and although my 13th-century Spanish is just as bad as my modern Spanish, it is still enough like Latin / French / English that is is easy to verify this translation is entirely correct. I had no doubt about that at all.

What I dislike of 'Arachnid' is that it is not the name of a species, but an entire class of species, which not only contains spiders, but also scorpions and other orders of animals. Like calling a piece 'Insect', 'Mammal' or 'Bird'. Or even perhaps 'Vertebrate'.

BTW, the thesis that names from mythology would be better known breaks down completely on this list; for almost any creature in it you can be very sure no one ever heard about it. So the question arises: why bother picking an existing historic mythological creature if  no one ever heard of it anyway? The more I think about it, the more I start to like 'Antigryph' (or 'Antigryphon', if you want): a piece that moves opposite to the Gryphon.

Like the Murray Lion, the Betza Unicorn may have been created through a misreading. The Unicorn described in Murray's account of Grande acedrex is not a bent rider. The description of the Gryphon says "A move compounded of one step diagonally, followed by any number straight." If the Unicorn were also a bent rider, its description should say something like, "A move compounded of a Knight leap to an empty space, followed by any number diagonally." But it doesn't say anything like that. Instead, it says "First move = Kt (but cannot capture), afterwards = modern B." This is saying that on its first move, it moves as a Knight without capturing, and on each subsequent move, it moves as a Bishop. Of course, it is possible that Murray bungled the description. But based on Murray's description, the Unicorn is not a bent rider.

I found a translation of the Alfonso document. This translation uses the name rhinoceros or rhino, and it says this,

The rhino’s move is composed of two different steps. First, like leaps like a knight. It may remain on
that square if it wishes or may also continue to any square on the diagonal(s) of that square,
maintaining its movement in a forward direction from that square.40

However, the footnote says, " Again, I thank Jean-Louis Cazaux for his help with my translation of the rhino’s move." For all I know, and he can correct me if I'm wrong, he based his understanding of the Rhino's move on Betza's understanding of the piece. Since he was just criticizing this article, maybe he got it from a source that got it from Betza. Anyway, that would put us in a vicious circle of not knowing for sure how Alfonso actually described the piece. That translation is too recent for Murray to have used. Is there a copy available of the translation or resource that Murray used to learn about this game? Or could Jean-Louis elaborate on why the original text supports this translation?

I like arachnid is better than acromantula.  I looked through my old D&D monster manuals and was supprised how few items begin with A.  "Apparition" is not great but not terrible.  For more conventional beasts, there is the ferocoius Ant Eater.  There is the Ankylosaurus dinosaur.  And there is a very long list here that I haven't looked through yet:

https://en.wikipedia.org/wiki/List_of_legendary_creatures_(A)

Not sure why you say that. Any suggestion from you that starts with 'A' would have been more than welcome. I had to go through a quite large set of mythical beasts before I found anything with an A at all.

Griffon is the commonly used English name for the F-then-R. There is no need to change that, as the name doesn't collide with anything else. If there was an exact translation of the historical name, it could be an argument (but not enough to justify changing a well-settelled name, IMO). But that is not the case here, and Griffon seems as close as you can get. Keeping the untranslated name (as the Spanish did for Alfil, and the English for Rook), would give either Aanca if we follow the Spanish (a bad idea, in view of the confusion sowed by Betza) or the Arabic 'Roc' (which most people would probably reject for being to close to Rook).

Only the W-then-B and N-then-B are in need of new suitable names, and Monoceros seems most suitable for the N-then-B, as it is an exact translation (to Anglicized Greek) of the Spanish name.

[Edit] Considering the lack of acclaim for Acromantula: I would also be perfectly happy with a fable animal of my own design for W-then-B. E.g. an Antigryph (or Apogryph?). Which is the opposite of a Gryphon (compare Contra-Grasshopper): A lion's head and fore-legs on an eagle's body.

OK, I understand. The idea should not come from me. Btw, the ferz-then-rook has also an 8-leg move. Good luck with your spiders, starting with A or not.

Why not my suggestion of Monoceros, ...

Because it does not start with an 'A'.

Besides, 'Monoceros' is just Greek for Unicorn. If we use those two names for different pieces, how should the Greeks distinguish them? As there seemed to be opposition against calling the Grant Acedrex N-then-B by its original name Unicorn, because we already associate that name with another piece, I think we should make Monoceros the English name of the N-then-B. This also sounds more like the originally intended Rhinoceros (which unfortunately was also already taken).

And note that I already have a piece called Unicorn in Team-Mate Chess. I tend to use this name for an augmented (or a royal) Knight (in this case WN), because XBoard has a piece image for it, and it is one of the most knight-like pictograms there that is not actually a Knight. I don't want two different pieces in Team-Mate Chess to have names that are just each other's translation in some other language. (Even though the move patterns are rather similar, the Acromantula just being a sliding version of the leaping Unicorn.)

I have the same so-so feeling than Fergus about inserting Harry Potter's here. Why not my suggestion of Monoceros, it is  a fantastic beast recognized in WP, it has a link with the Unicorn. As Unicorn is the N-then-Bishop in Alfonso's description, why not Monoceros for W-then-Bishop? The difference between the 2 moves is thin, so is the difference between the 2 names.

I am not so sure about that. I had no idea what a Kirin, Wyvern or a Manticore was before I looked it up. I doubt whether many people in the street where I live would know what a Griffon is. I think it is a safe bet that more contemporary people have read Harry Potter or seen the movie than that have read the Odyssee.

I don't see any difference between Harry Potter stories or other contemporary fantasy litterature and ancient myth.

My main concern with names from Harry Potter is that they are not going to be recognized as easily as names from folklore, mythology, or zoology. Although I've read Harry Potter now, I was already an adult when it came out, and I've already forgotten most of the monsters and magical creatures from it that I wasn't already familiar with.

Naming chess pieces after Harry Potter?  yuck

The name of the individual spider was Aragog. But when I Googled for that name, most references immediately mention that Aragog was an Acromantula. E.g. https://en.wikibooks.org/wiki/Muggles%27_Guide_to_Harry_Potter/Characters/Aragog . Since I am sold to an 'A', it is the name I will use in Team-Mate Chess.

If you want horns, Triceratops comes to mind. But I don't see why arachnids should be discriminated against.

I read the whole Harry Potter series last year, and I think I know what you're talking about, but I don't remember the name Acromantula. The piece does have a movement pattern that is suggestive of a large spider, though. Based on similar reasoning, I used the name Spider for the Alfil/Dabbabah compound in Interdependent Chess. I guess the name Acromantula is supposed to suggest an acrobatic tarantula, though that wouldn't account for the m in the middle. Arachnid would be a more familiar name for most people, though it's also pretty generic. Ultimately, the choice will be up to whoever uses it in a game.

Hmm, I'm not a fan of the spider, even a monstruous one. The link with Rhinoceros/Unicorn is too remote. We need an horn :=) But also because Musketeer Chess has proposed and is even selling a Spider already, even though I don't like at all the definition he used.
What about the Monoceros, see https://en.wikipedia.org/wiki/Monoceros_(legendary_creature) I'm pretty sure that it was never used in CVs (I'd be surprised) and there is an obvious parenthood with Unicorn.

How about 'Acromantula', then? In the Harry Potter series this is a monstrous men-eating spider. I like the spider connection, because spiders have 8 legs, and the W-then-B moves along 8 rays.

And it keeps me happy that it also starts with 'A', as the Fairy-Max implementation of Team-Mate Chess uses this piece with A as ID, and changing that would break backward compatibility with the previously saved games.

To Greg Strong: 

you wrote: "As Chess evolved the elephant was enhanced from leaping diagonally to sliding diagonally.  It was at a later point that the English name (and maybe other languages) was changed to bishop while other languages, such as Spanish and Russian retained the existing name."

As the matter of fact, no, it didn't happen that way, they didn't change the name after the move was changed. The name was changed much before.

Old chess, similar to shatranj, was transmitted to Christian countries and reached England about 1050. The "Fil" was soon called Bishop there and in other Scandinavian lands. For example, the famous Lewis set has pieces depicting Bishops. The modern move for that piece (although it had some forerunners in Grant Acedrex or in Courrier Chess) has been adopted about 1475-1500. So, during almost 500 years the piece called Bishop in English was played like the one we call Alfil in our chessvariants.com pages.

Btw, same thing for the Queen, called a Queen and played as a Ferz during 500 years.

Interesting discussion. I don't want to push for my choice of Eagle for F-then-R as Gryphon is more popular in CV community. Eagle is just my personal choice in the frame of Metamachy as it has some resonance with the Lion, carrying some heraldic meaning. Btw, my use of Lion, and also Elephant is also personal and I don't push. 
In the case of Aaca by Betza it is primarly the result of a wrong reading of Murray. There are more examples in that page that demonstrate that Betza read it very very quickly, the least to say. So, we shouldn't keep what is really a mistake.
N-then-B is exactly the Unicorn, drawn as a Rhinoceros by the medieval artist in the original codex. I don't see the need for another word, but if you believe so, why not Hippogrif. Finding another mythic animal for W-then-B is a good idea. Maybe one with a big horn.

Well, I suppose it depends on whether one considers it more important how the piece moves, or that it stayed in the array. The problem I see with the latter is that I consider Courier Chess as an important milestone on the evolutionary path of modern Chess, and consider the Bishop as a descendant of the Courier rather than the Alfil. But it is clear that I am outvoted here.

I still dislike Eagle for F-then-R, though. If a more bird-like name is desired, I would go for Harrier. This at least also exists in a chimeric (or should I say cyborg?) version that is able to take on Elephants...