@HG,

All my tests are working. Thanks!

I don't know if it is me, or if it happens to others too, but I confess: I don't catch nothing at all in the explanations of Time Controls. It is not a problem of English, I'm used to read complex scientific stuff in English. Maybe it is because I never played chess in official competitions and I'm lacking some notions.

I wanted to put a time limit because I've been frustrated in some recent games to see opponents stopping to play after being in a difficult situation. Doing so, they never loose. An unfair behaviour certainly, I wanted to avoid this.

So I set a time limit but frankly I don't understand at all what I have selected and the effect it may have. I just guess there is a limit somehow.

Why, people in Europe and America are against the ancient Historical games?

The kanji for 'Hawk' (鷹) in the piece Lion Hawk is the same as used for 'Falcon' in the Horned Falcon; while the 'Eagle' (鷲) appears in both the Soaring Eagle and the Free Eagle.

I am curious if the historical moves of the Lion Hawk and Free Eagle are not just Lion + Bishop and Queen + double-move Ferz respectively.

Could the Lion Hawk and Free Eagle instead have moved as Lion + Horned Falcon and Queen + Soaring Eagle respectively?

The Lion Hawk would be more powerful, able to move as a Lion and slide as a Queen except vertically forwards.

The Free Eagle would be slightly less powerful, moving as a Queen with the added Lion power covering two spaces each on the forward diagonals.

This could be the reference that the Free Eagle could move twice as a 'Cat Sword' (Ferz) in the Shōgi Zushiki and Sho Shōgi Zushiki, perhaps created from ambiguity in how the move is described.

To play games the way one plays correspondence games on lichess or chess.com, one simply has grace time without reserve time.

E.g.

If we have no (0) reserve time (Edit: In other words, no “spare time”, no “min time”, no “extra time”, and no “bonus time”), and we have a grace time of 24 hours, this means, as soon as one moves, the opponent has 24 hours to reply to your move. If they fail to reply within 24 hours, they lose the game.

Lichess makes things simple by having no reserve time whatsoever, and having only the following settings for grace time (which is simply the time needed to make a move before losing the game on Lichess) in correspondence games:

• 1 day
• 2 days
• 3 days
• 5 days
• 7 days
• 10 days
• 14 days
• Untimed

So, for dealing with “this guy never moves once they are losing”, having a grace time of 14 days ensures that both people have plenty of time to make moves (especially in today’s world with smart phones everywhere), but that forgotten games are won by the last person to make a move before forgetting the game exists.

Ignoring “Min Time”, “Bonus Time”, and “Bonus Period”, “Spare Time” is, using a Fischer (increment) chess clock the amount of time given for the game, “grace time” would be 0 (since a simple Fischer clock doesn’t have this), and “extra time” would be the increment (the amount of time given for each move).

Let me explain this with an example. We have a game with 5 days (120 hours) of spare time, a grace time of 24 hours (1 day), and an extra time of 1 hour.

The clock starts, and Alice (white) is playing Bob (black).

• Alice makes her first move as soon as the game starts. She now has 121 hours spare time: 120 hours at game start, then 1 hour added after making her first move.

• Bob replies 23 hours later. Since he replied within 24 hours, he loses no spare time, but gets one hour of extra time. So now Alice and Bob have 121 hours of spare time. Grace time is always the same for each move.

• Alice is busy the next day and needs 26 hours to reply to Bob’s move. The first 24 hours were against her grace time, so only the final two hours of her delay moving went against her spare time. She lost two hours of spare time (119 hours now), but gained one hour after making her move (so she now has 120 hours of spare time again; with grace time, if she doesn’t move within 144 hours, she loses).

• Alice created a lot of tactical complications for Bob, so Bob needs 72 hours to reply to Alice’s move. 24 hours is grace time, so we only look at the remaining 48 hours when calculating spare time lost. Bob lost 48 hours spare time taking so long to make his move, but gains one hour after making his move. 121 hours - 48 hours (delay moving after grace time) + 1 hour (extra time) = 74 hours left (with the 24 hour grace time, Bob needs to make his next move within 98 hours or lose the game)

• And so on.

(The time control that works best for me is 2 days: 48 hours to make a move or I lose. The problem with one day time controls without reserve time is that every day I have to make my move earlier in the day, but, with two days, if I make a move every day, it doesn’t matter what time of day I make the move. There are ways to have one-move-a-day without the issue of having to make my moves earlier and earlier each day, but our time controls are probably already too complicated).

I think this is unlikely. I have never seen the Edo-era description of Tenjiku Shogi, but I do know how such descriptions looked in general. They basically showed a drawing of the initial position, where each square contained a drawing of the way the piece moved, with the kanji of the piece name in the center. Sliding moves would just be radial lines, and it would be immediately clear whether the Lion Hawk also had orthogonal slides.

Only complex moves, such as the Lion, would not be obvious from the drawing, and would be described by an additional line of text. I once have seen the picture for the Teaching King (a piece from Maka Dai Dai Shogi); it had lines in 8 directions, each with 3 perpendicular line segments crossing it for indicating the multi-captures of teh Lion Dog. (And the text line then said it would move like Queen or Lion Dog.)

The piece images are not showing up on the diagram for this game

I'm wondering if there's an easy way to balance a variant where each side would have a random selection of pieces (excluding pawns and Kings). The best I can think of is making ALL pieces contagious, like the werewolf in Werewolf Chess. Maybe pawns shouldn't be contagious. Does this seem like it might work?

It appears the CVP website has been switched from http to https. Since the piece images are on my own website, which is http, the browser now refuses to display them.

In this case I can easily fix it, because the same piece set probably is somewhere on the CVP website, and if not, can be uploaded as user graphics. But the same problem will now manifest itself in other places. In particular, the 'Diagram Editor with Scalable Graphics' will be broken. This refers to a C program on my own website thar dynamically generates piece images according to specification, and now also is no longer accessible. So far Fergus did not manage to compile the same program for the CVP website, so that it could run there.

[Edit] Interesting. On my PC with FireFox all this works. Perhaps I have switched off this pedantic security feature there; I don't really remember.

It appears that access to the render engine is now permanently boken for everyone using a browser with standard security settings, because of the move to https. It therefore becomes important to migrate the engine to the CVP website. So can we revive this effort?

If I knew what Linux version exactly is powering the CVP server, I could install it myself in a VM, and have a try at compiling the rendering engine. I seem to recall it is some version of CentOS (although that is not mentioned in this discussion?).  The renderer is based on XBoard's board rendering code. I do think XBoard is available for CentOS, which means it must be possible to compile it, or figure out how it was patched by the maintainer to make it possible to compile it.

@HG,

It is really annoying that the imitators are traded for nothing. Maybe you can do something about this when you find the time, like when the move button is triggered the value of the imitator is updated with the average of the values of foe pieces.

Thank you Samuel for your explanations. I would recommend to the Editors to put your example in the explanation of those time notions. Not only it is complex to have “spare time”, “min time”, “extra time”, “bonus time”, etc. but the explanations, sorry to say, are themselves so complex that after reading the end it is impossible to remember. In other word, it is not understandable.

In my opinion, the way it is practiced in Lichess is largely quite enough and sufficient for chess variants play.

I would vote for simplifying our process.

Thanks again

Are you sure this is the problem? Because what you describe is what I already do. (That is, I set it to the weighted average of the value of all pieces, where the weight is equal to the value. This because I assume that stronger pieces will be moved more often than weak pieces. And I subtract 30% of the variation in this, because I assume the opponent will adapt his move choice to make the imitator less useful, if he can, by moving more weak pieces than he otherwise would.) When you click the 'move' header in the piece table to see the values, you will see that the imitator does have a finite weight.

The procedure could be a bit improved. (E.g. I now take the average of all pieces, while it should really just be opponent pieces. But if that would be very different the game is decided anyway. And it does not take account of an imitator's fixed moves, if it had any (e.g. if you define WfI).) But whatever flaws it has now, it should never lead to thinking the imitator is worthless.

Perhaps the problem is simply that the AI doesn't search deep enough to see that an Imitator can be easily trapped.

The Japanese Jostlers pawn is a regular Shatranj pawn (though with a different promotion). The image editor doesn't allow me to mix piece sets, unfortunately.

I think I have found a bug in the diagram below:

https://www.chessvariants.com/rules/grand-apothecary-chess-alert

The AI, while playing black, promotes to rook at rank 4 (1 being the brouhaha rank). It supposed to de able to promote to rook since the 3 rank downwards. The weird thing is that I checked it manually with the diagram and it worked fine. The trouble is only when the move button is pressed.

Undertaker

The description of the Undertaker says it promotes to the Knightrider. I believe this is incorrect -- judging from the description of the Knightrider and the Dayrider, it should say the Undertaker promotes to the Dayrider.

A problem might be that if you allow both Pawn and Berolina as promotion choice, you don't only allow Berolina to promote to Pawn and vice versa, but you also allow Berolina and Pawn to stay themselves. Since the choice would make no sense on the last rank, where neither of these would have any moves, I suppose this is not a problem, but rather exactly what you want.

I don't see the way to ban promotion of regular pawns to berolina pawns and vice versa.

For me the CVP is really really slow. It's really a pain. What's going on?