Comments by JorgKnappen

I think I finally found it, it must be Nadvorney's Spherical Chess as described here

https://www.chessvariants.com/boardrules.dir/spherical.html

@Georgi Markov

Thanks for your publication on Sultansspiel and Kaiserspiel, and special thanks for publishing it in an open access journal. Now I finally know where that ominous "Ludwig Tressau" comes from.

However, I think that the common publishing place Leipzig is not suitable to draw far-reaching conclusions: At that time, Leipzig was the hub of German book publication and had the largest concentration of publication houses all over Germany. Also, Ludwig is the most probable expansion of the initial L. and may be an interpolation by Oettinger. The second most probable expansion would be Louise or Luise, a feminine name, and the fact that the author hides consistently behind the initial makes this possibility even more probable.

Having said this, Tressan is an extremely rare surname in Germany, and Tressau is even more obscure. I searched some huge databases of personal names (telephone directory and DNB Normdatei) and Tressan occurs once or twice, but Tressau has no hits at all. It should be feasible to identify that specific "L. Tressan/L. Tressau" using genealogical databases without sifting through too many hits.

While adding some tags here and there, I am thinking of tagging some more square boards and I need agreeable names for that tags.

Two are quite clear:

16x16 hexadecimal (from Greek)
20x20 vigesimal (from Latin)

But what about the other numbers 11, 13, 14, 15, and 18 (I leave out 17 and 19 just now, they are probably too odd)?

I'm thinking of

11x11 onzenal (from French)
13x13 treizenal (also from French)
14x14 quatorzenal (again from French)
15x15 femtenal (from the metric prefix "femto" 10^{-15}, ultimately from Danish 15)
18x18 attenal (from "atto" 10^{-18}, ultimately from Danish 18)

What do you think?

I don't like the khaki/smoke scheme and I think this can be pinned to the following two factors:

1. It does not from a well-defined board boundary on the present background colour (this is probably easy to cure with an outline)

2. The colour difference between the interior of a white piece and a light board square is just noticeable, but not really a contrast. This does not look right.

What has happened to the diagrams here? They show 10x19 boards with a lot of blue non-squares to me.

Here is one genuine German Franz Tressan from Verden an der Aller: https://portal.dnb.de/opac.htm?method=simpleSearch&cqlMode=true&query=idn%3D110743078X

My pieces are free to reuse and I feel flattered that you like them.

I find the square board tags quite handy, they allow a quick navigation to other games on the same board. Going to the game info page and selecting the right category (best working is the number of cells in the case of square boards) takes longer.

And I really love the piece tags.

As far as I can see there is no rule that forbids moving the King back to the place where it came from (at least, when the King move wasn't motivated by escaping check). So a situation can occur where the two players just move the King between two squares in an endless loop and the game makes no progress.

The name of the author is still kind of a mystery. I think the author is best identified as "L. Tressan" (Ludwig is obviously an interpolation and not really sourced). In the comments on Sultan's game (Sultanspiel) we had a longer discussion on the mysterious "L. Tressan".

Also, the title of Tressan's book contains a typo, it should read "seine" instead of "siene".

I think movement diagrams from the light blue squares would be a good addition to the game description, those squares are qualitatively different from the dark blue and white ones.

This piece (Nr. 87 "King Cheetah") is featured as Pegasus in Beastmaster Chess by Glenn Overby II (2002)

@H.G.Muller Thank you for the interactive diagram!

There is an alternative German plural to Mann, it is Mann/Mannen with an archaic flavour and a restriction in meaning, it is a soldier or a servant of the king only, but not any male human being.

The Evangelist has also the can-mate property because it covers all range-1 squares like a Mann does, and King+Mann can mate a lone King.

@HaruN Y: Thanks for the interactive diagram here and for Zabel Chess.

Interesting variant with innovative promotion rules.

The rules are inclomplete with respect to double check and pincers on both Kings, it should be specified what happens than. Technically, the fake King is in check but not necessarily checkmated in such a situation.

The rare case of double checkmate should also have a special mention in the rules: Is this the end of the game with a win for the checkmating party, or will the game continue with the fake King demoted to a pawn and the checkmating piece being removed?