Dark Chess

[George Tsavdaris]

George, just to make sure:

After each moves, both players get an update of the board, right?

Right. For the squares of the board AND (of course) the pieces that stand on them!

The program at the link does not seem to do that.

Yes that program does not follow Dark Chess rules at all. I still haven't been able to figure out what it is doing and the pattern that displays the board, but i don't care anyway. It's just wrong.

It is not only that you cannot ponder effectively: you really get information by it you otherwise would not get. E.g. I play e2e4, and on the opponent's move e4 disappears from view (as it was unprotected). If Pe4 had been allowed to 'look around' after my own turn, I would now know that what captured it is not a Pawn. Otherwise it could be anything.

Yes it just plain wrong. The implementation of the rules of Dark Chess as also the logic behind its own rules.

There is a tricky point for a GUI about Dark Chess that supports engines.
What the external observer/viewer should see?
Since the viewer can't cheat and say to the engines the board position, one option would be to see the whole game, like what Winboard sees, i.e see everything, no dark squares. Each engine of course sees the darkness, different for each side.

So this is one option for the viewer of an engine-engine game.
But it's not very interesting since he will not be able to have the suspense and the tension the element of surprise gives when viewing the game from one side's perspective.

So in my opinion a setting where the viewer can choose the perspective of each engine, that is how each engine sees the board, would be a very interesting feature.
I.e to choose between normal view seeing all board and pieces, white's view seeing only what white should see and black's view seeing only what black can see.


Anyway since this will probably be my last post here in CCC until some things change and you don't post to Rybkaforum much, i want to say a big thanks for all the amazing contributions you have made by making Winboard a superb GUI in all aspects, as also Fairy-Max with its variant support.

I will watch your tournaments but just be silent. Until and if i will return posting here again(i guess these 2 guys will either be bored of posting crap or moderators will decide that enough is enough, so i guess CCC will soon be back to normal again) have a nice time with all the games!
Bye and see you....

[hgm]

Well, I do read Rybka forum too. It is just that there hardly is anything interesting there. No engine programmers, and no one that is interested in variants. I did announce the live Spartan games there, but (like I expected) there was zero response.

[hgm]

[adamh]

Thumbs up for your productivity!

1. Maybe a stooopid question but I am not a Winboard user. I just cannot understand how you would play a normal engine?? Unless Winboard shows all to the engine. Quite a handicap, but fine for prototype. Is this it?

2. UI improvement suggestion. You must have played the game to appreciate this, but at all sites the invisible squares are gray "?"s, which sucks. And in your first shot: all black..... It would be soooo much easier to think if the b&w square colors would be visible as in the screenshot in said link:
http://www.silvertreerpg.org/dark/

Even if he didn't get the game right, he sure got the display right, IMHO.

[hgm]

Yes, playing a normal engine is only for testing, as the darkening currently only works in Human vs engine mode. I would not be able to test at all if I sent commands that only a Dark-Chess engine understands, as no such engine currently exists. So I have to first debug the UI, before I fix the back-end. Unless I make a dummy engine myself, of course, which I will probably do at some point.

I am not sure about George's idea. Currently in Two Machines mode, I display the full position, because it is what I would want to see when observing an engine game. How does ICC treat this for observers of a Kriegspiel game, btw? Perhaps I should make an extension of thr 'flipView', where it does not cycle through 2 states (board orientations), but through 4:

white below, dark -> black below, dark -> white below, full -> black below, full -> ...

where the dark/full would only have effect in variant dark, when not playing. (So in all other variants people would have the normal alternating flipView behavior in other variants, and when playing the opponent would always be darkened.)

I am not sure about your second point. Actually I found the checkering of the darkened region in the silvertree program quite confusing. E.g. a darkened dark square amongst light squares, like a5 in the WB picture above, is hardly noticeable as darkened, so it is easily confused for an empty square. Why do you think it is helpful to have it? Perhaps a slightly less dark shade of black (like the black piece color) would do it. Are there any other opinions on this?

[George Tsavdaris]

I am not sure about your second point. Actually I found the checkering of the darkened region in the silvertree program quite confusing.

Utterly confusing for myself i would add.

E.g. a darkened dark square amongst light squares, like a5 in the WB picture above, is hardly noticeable as darkened, so it is easily confused for an empty square.

Yes absolutely you can't concentrate on thinking with all these almost similar squares.

Why do you think it is helpful to have it? Perhaps a slightly less dark shade of black (like the black piece color) would do it. Are there any other opinions on this?

I think the following one is the best to have. You can perfectly visualize the board this way. (the "best" word, does not go because the squares have the ? sign or something-no this is not necessary of course-, it goes because the square's borders are visible so you can easily visualize the board)


Your full black is OK too and i think we can use Winboard.ini options to change the color of the grid lines to something else than black in order the square's borders to be distinguished.
I haven't tried to change grid's line color anytime because black for the grid is fine in all other variants, but in Dark Chess and your implementation of black color(unless this can be changed to something else also e.g gray, so the squares would easily be distinguished) makes a sea of blackness that is a little difficult to think by visualizing squares.



BTW i decided that there is no reason not to post here in programming section since this subforum seems immune from moronic posts so it's safe.

[George Tsavdaris]

Even if he didn't get the game right, he sure got the display right, IMHO.

I like HGM, find this implementation a bit confusing. While thinking on that board with that implementation you lose unnecessary time for distinguishing between which squares are currently visible and which are not, in other words you can't have a complete feel of the board to think in patterns and every time you look at the board you got confused.

While with the complete darkness, i.e using the same color for every "dark square", your process of visualizing the board and analyzing moves is easier. The issue that black or white "dark squares" are not visible is non existent since our brain can work it out instantly because of the nature of the board as diagonals are of the same color and white and black squares alternate both in files and ranks.
Someone that knows Chess understands what i'm saying. That by seeing the square's borders, even if all board is dark you just know what color is every square and even much more easily if you see a part of the board then you immediately can visualize all board.
And as you don't lose time on thinking which squares are "dark" and which are not, this implementation i think is much more strong for playing the game.
In my opinion always.

[adamh]

Why do you think it is helpful to have it?

I think so out of practical experience I play dark-chess quite a lot at brainking. Do you play a lot?

If for example if you need to visualize long (obscured) diagonals or visualize the potential squares of a knight that just move out from sight, that is hard when obscured squares are a solid block. Or perhaps an even better example; you have captured you opponents dark-squared bishop you need to visualize the potential squares for his light-squared bishop.

I meant that it would be excellent to use the idea of displaying square colours. Not that this particular way is ideal. Two other ways to achieve it:

Display a full board with all your regular square colours with a "?" on hidden squares.

Display a full board with all your regular square colours (light brown and dark). For hidden square make them light/dark grey!

[hgm]

OK, this should do as a compromise, then: light and dark black.



Like I already remarked in the other thread: the user can now choose his display mode when he is not playing (e.g. TwoMachines mode, but also EditGame etc.) through Flip View (the F2 key). This cycles him through 4 states: two board orientations times 2 modes (dark / full). The dark side is always above.

[adamh]

Only if George gives you his permission