Ratings & Comments

Indeed, a user promotion choice does overrule everything else. If a fixed promotion is required for pieces that would offer choice, the promotion query should be suppressed. Not only because it would prevail, but because it makes no sense at all to let the user choose and then do something else.

The mechanism the Diagram uses for this is to call WeirdPromotion() with the promo parameter set to 1021 (which is not a valid piece type), to inquire whether there is promotion choice. When this call returns 1001 the query will be suppressed, when it returns 1000 a query is forced, and in any other case it decides itself (based on maxPromote, promoZone and promoChoice).

In the AI it works slightly different; there (for a piece that could normally promote) WeirdPromotion() is called with promo equal to the promoted piece (as per promoOffset), and to suppress the promotion this would have to return 1022. It is the deferral (promo=0) that must be turned into a kamikaze move by returning 251, so that moves that would not naturally promote also get burned.

So when a passive burn is detected, WeirdPromotion() should return 1001 if promo == 1021, 251 if promo == 0 and 1022 otherwise.

@Fergus Have you any idea about what is going on!

No, rules 2-3 means that pieces cannot move from one "domain" to another except as in a 4d (asymmetric) game.

But it does look like I may have been wrong about the title: the domains are each infinite, while apparently the domains are supposed to be limited to an 8x8 grid.

Fergus wrote:

"... it looks like this game has 5 ranks, 5 files, 5 3D rows or levels, and 5 4D columns or realms."

Yes, I suppose it could be put that way.

I'm thinking of making Masindam puzzles soon !

I cannot use the item quick-edit script (as an editor) because the form does not have the new BoardRealms input (though perhaps the quick edit can be deprecated now that the author list population isn't so slow), and the database apparently won't allow it to be null. Again, I really think allowing nulls for non-game items would be best, and BoardRealms should be defaulted to 1 in any forms.

When representing a 4D game in two dimensions, which is what we're limited to on a computer screen, it makes sense to pair together a higher-dimensional label with a lower-dimensional one. This is especially so with something like Game Courier, which gives you only files and ranks to work with. This can lead to a coordinate like Dc23, which I hovered over randomly, which transposes the second and third dimensions. Bearing that in mind, it looks like this game has 5 ranks, 5 files, 5 3D rows or levels, and 5 4D columns or realms.

I also experienced this bug with contagious promotions. It seems the shogi promotion prompt is suppressing the WeirdPromotion result.

I edited my previous comment, for any who missed it.

The diagram on the page superficially resembles that of Sphinx Chess, but it has only two axes of movement, the vertical and the horizontal. If you follow the lines of movement of pieces on this board, you will see that multiple boards have been placed together to create a larger playing area on which pieces are still moving in two dimensions.

If I recall/recognize the diagram correctly, at the diagram's bottom e.g. 'Ae' indicates (4D) Board column A and (2D) board file e. The labels at the sides e.g. '15' indicates (4D) Board row 1 and (2D) board rank 5 (a column being like a file by my understanding). True for both the rules page diagram and the preset diagram.

edit: I had to re-read the labelling by zooming in on the bottom of the diagram, so I could tell lower case letters apart from numbers - my eyesight/laptop's not the greatest, maybe. Also, there are over half a dozen 4D CVs in the database, as I recall seeing (I got a few of my own published over the years). Not as many as there are 3D CVs, true.

The title of this page seems wrong on both counts: it is not infinite, and it is 4d, not 3d.

The introduction discusses infinite chess, but the eventual game description is clearly 4d (in an asymmetric, "2d+2d" way like Parton's Sphinx Chess).

Playing about with this diagram I did seem to have run into some strange bugs:

• Passive burning works correctly, but not when the promotion dialogue turns up. E.g. Rook General g4xg13 from the opening setup survives even though it lands next to the Fire Demon. If I promote it then move it next to the FD again it's burned as expected
• Under certain conditions (it seems to be contingent on whether it's a piece's first move), promotion seems to become corrupted: it gives me the promotion dialogue, but doesn't promote it regardless of which option I select. Subsequent moves allowing promotion (into/within/out of the promo zone) likewise ask but don't react, and the move seems to permute surrounding pieces in an unpredictable way, often with the same highlighting as for burn victims, though sometimes on squares with pieces still (or newly) on them. I think this is contingent on whether it's a piece's first move:
  • 1. RGg4xg13=GG works (besides the above bug allowing it to survive)
  • 1. Pg5–4 Pg12–g11 2. RGg4xg13 similarly works
  • 1. Pg5–4 Pg12–g11 2. RGg4–g5 Pg11–g10 3. RGg4xg13 triggers the bug

The two bugs together also mean that a piece subject to the second bug can never be passively burned within the promotion zone

Since a toroidal board does not count as a 4D board, I removed the 4D category from this page. A 4D board is one where each coordinate is designated by 4 values, each one representing a different dimension. But each coordinate in this game is designated only by its rank and file.

I have updated the database and relevant scripts to better accommodate 4D games by including a new field for the 4th dimension called BoardRealms. However, I'm not sure what value to give it for this game or what value to change BoardLevels to now that it doesn't have to do all the work for both the 3rd and 4th dimensions.

The Diagram I posted only does active burning. Sorry I was unclear about that.

Adam implemented the burning by embedding a custom script for WeirdPromotion. Where he first tests whether a piece lands next to a burner (and in that case returns 251 as promotion code to make it a kamikaze move), and otherwise returns 512 when the moved piece is a burner.

I only used the captureMatrix parameter in my Diagram. There is no formalized way yet to specify passive burning by Diagram parameters; you would have to supply a JavaScript extension.

Here's an Interactive Diagram for Tenjiku Shogi.