Comments by HGMuller

Well, in case you ever run into trouble with the size of the promotion popup: in terachess-view.js there are the following lines:

  45         // Reducing the promo frame which was overflowing the board screen
  46         View.Game.cbPromoSize = 1100;

So I suppose this is the way you can resize it.

This Manticore is really something. It doesn't have the 'potent' property that would allow it to force mate in combination with any piece that can roam the entire board. But it has all the other properties that are useful if the right kind of partner is present. I yet have to find a piece that it cannot force checkmate with:

• It cannot have a W move, because that would make it 'semi-potent', and the Manticore is 'forking'.
• It should also not be able to make a W move in a 3-move tour, for the same reason.
• It cannot have a D move, because that would make it potent by itself.
• It should also not be able to make a D move in a 3-move tour, for the same reason.
• It must not simultaneously attack two squares separated by a D move, because that would make it forking, and the Manticore is semi-potent.
• It should not simultaneously attack two squares separated by an F move, as the Manticore can trap a King on a2-b1.

I thought I had a piece that satisfied all these criteria, in the form of a Crab that was missing one of its moves (fsrbN). But it found a trick to circumvent the normal requirements, by the fact that the N move the Manticore makes is lame, and can be blocked at the W squares. It blocks this move with the Crippled Crab from attacking the corner in a position that otherwise would have been a stalemate, and then deliver a discovered check there.

It seems a lame piece can sometimes do better than a normal leaper!

It indeed behaves very strange. King and Queen are allowed to capture their own Bede.

I think it is not able to recognize to whom the pieces belong when you use non-alphabetic characters in their labels. Piece IDs are supposed to be letters. When you ask for trouble, you usually get it...

I'm lightly torn on whether to include this information on the page too; it's not the main subject of the page but it's interesting and it'd be a shame to have it hidden away in a comment.

I was wrestling with this problem too, when adding checkmating paragraphs for other minors in the Piececlopedia. For majors it is easy, and you can simply say "this piece can force checkmate...". But for minors it is really useful information with which other minors it has to be paired to be able to force checkmate, and when it can not. But the paragraph tends to get long, and repetitive between pages, when you have to explain the details every time.

Perhaps the part of the explanation that applies to many pieces should be made on the Applet page itself. I could add paragraphs there to say something like "The XXX can switch its attack from one square to a square orthogonally separated by two steps, which allows it to checkmate in combination with almost any piece that can roam the entire board", and similar things for semi-potent and forking pieces, which initially are hidden, and which could be opened by a request in the query string when they apply, the XXX automatically replaced by the piece name.

[Edit] I have now done this, and took the liberty to switch on the explanations for semi-potent and forking through the URL in the Steward page.

When I added the checkmating paragraph I also added the mention that this piece nowadays is also known as Lancer.

Perhaps someone who knows how to do this can add a link to the page in the Piececlopedia index under that name.

I still don't like it. The problem of poor visibility of the thin lines has been addressed here by changing the fill color, but this is out of style with the rest of the Alfaerie set.

If such different coloring were to be used, I would want to reserve it for indicating divergency (as I believe the pieces in Desert Pub do).

I am now using a standard sentence as Checkmating paragraph for most pieces, like

The XXX cannot inflict checkmate on a rectangular board with only assistance of its own King, and is thus a minor piece. Even with a pair of XXXs you cannot force checkmate on a bare King, but paired with another minor this is sometimes possible. Try it!

What exactly the role of the XXX is, is then explained on the Applet page, as well as what property the other piece would need. Obviously the second sentence would be different if a pair of XXX can checkmate, and in that case I would preferably use the pair as an example.

Only if there is something interesting to remark that is specific for the piece, the paragraph is longer.

Concerning weak pieces: it turns out Ferz + Wazir can force checkmate on 9x9, provided the Ferz is on the shade of the corners. (And not at all otherwise.) On 8x8 this end-game is generally a draw, but that is because the checkmate can only be performed in two of the corners, so that in general the distance to a deadly corner is much larger than on 9x9. On 6x6 the deadly corners are again close enough to shephard the bare King there when it has taken refuge in a safe corner.

I have been running the open-source FICS code on my server for a while, mainly to organize on-line tournaments for computer programs. I did add a lot of variants on it too, such as Capablanca 10x8 variants, Spartan Chess. No one would ever play those, of course, but there were hardly any human visitors of that server anyway, and I never organized computer tournaments for those on that server.

I don't know if that old source still compiles on CentOS; otherwise it would be possible to run it on the CVP server as well. But it would have to be changed a lot for allowing a wider variety of variants, and in particular easier implementation of new ones. Furthermore, the only client capable to run the variants is WinBoard/XBoard, while nowadays people lose interest for anything you cannot play directly in your browser.

2)"Can you think of any positions in which castling would be the only legal move (illegal in a no-castling variant)?"

It is pretty obvious that castling is never the only legal move: if you can castle you are not in check, and you can move the King one step towards the Rook, and the Rook anywhere between Rook and King. Unless you are talking about Chess960 and Fischer castling:

As Aurelian explained, this was Greg's initiative. He wanted to get rid of all these silly names obtained from trying to pronounce the Betza move notation. So in ChessV Bede became Cleric, Half Duck became Lion, and he asked if anyone had an idea for Fibnif. Aurelian came up with Lancer, and we liked it, because the Fibnif is a narrow piece, and in battle Lancers cannot easily turn sideways, because of their long lance.

It is not a variant. It is just orthodox chess played from a different starting position, a position that already is in the game tree of orthodox chess. Tournaments of such games are known as thematic tournaments, where you are obliged to play a certain opening line.

We are also not going to make pages for a 'variant' that only differs from FIDE by the Pawns in the King  file starting on e4 and e5.

I am not sure what you mean by that last sentence. If you would think 2 sec in a 3 sec Bronstein game, your clock will not advance. So I would say you did receive a bonus of 2 sec in that case.

In Bronstein TC the clocks just start running after a delay, each move.

That is the right principle. But as the quoted text says, I am not sure the ID would understand this, as bracket notation is not fully implemented.

Since it is always clear in bracket notation what belongs to the same leg, I suppose there would be no reason to forbid compound legs. The XBetza compiler already expands the moves like you did here, not for different atoms, but for different directions of the same atom. (So aK gives 56 moves in the move table!) Your Thaumaturge could then be written as [xKCZ-KCZ]. Of course there is currently no support for this at all in the ID (except for the WF case implied by K), but it is a thing to keep in mind when implementing direct compilation of the bracket notation.

I have now re-instated the buttons for selecting the second piece on the configurable 3-vs-1 Applet page. The fist piece will always the one specified by the URL, which is supposed to be the topic of the page. But the URL can specify the second piece through other=X in the query string, with a limited set of minors X. (And it will default to using a pair of identical pieces.) The user can then select another partner for the piece the page is about, from the repertoire offered by the buttons. (Which is pretty large.)

This pretty much finishes this configurable Applet page; I don't see any reason for letting the user change the board size. (Which can be configured through the URL, and would not be allowed to go above 10x10 anyway for capacity reasons.)

While adding checkmating info for most pieces in the Piececlopedia, I encountered some new mating patterns. (E.g. how an FAD can be used to checkmate in corners of the shade it is not on, or how lameness/sliding sometimes can allow mates that would be impossible with the corresponding unrestrained leaper. I could add these to the main 3-vs-1 Applet page, which already discusses the more common cases. But I wonder if it wouldn't be better to split up that page, to leave it purely for the 3-vs-1 Applet, and put the general theory in an independent article (to which it then refers). As it is the theory is already a bit hidden far down on the page, where people might never scroll.

The Applet page could use some enhancement anyway; the current one cannot do hoppers and bent (or ski) sliders. While the EGT code has already been upgraded to handle those. This is an interface issue, though. In the general 3-vs-1 Applet you must specify the pieces through the move-definition aid. I have no ideas on how this could be enhanced to allow specification of bent trajectories or hoppers. Perhaps there should be buttons in addition to the move-definition aid, similar to those on the configurable page, which could be used to select the most common hoppers and bent riders directly. (E.g. for the minors the Manticore, Osprey and Ski-Bishop moves.) Or perhaps better, to add such moves to the move set currently specified in the aid panel.

I now made a slight modification in the Diagram's AI (of betzaNew.js): the condition under which a move is always searched is changed from total gain > value of capturer (which in conquer could go on for ever, with a crash as result) to one where this only holds for moves that do not unload anything, and that moves that do unload something are only searched if they capture a piece of a type higher than their own. (This assumes pieces in the table are sorted by increasing value.) This thus discards the gain from the recruitment; in the old way RxR would gain you two Rooks, and would qualify; now it no longer qualifies, as R=R. It would still always search RxQ, but then two half-moves later not the reverse QxR, even though in the old way 2R might be more valuable than Q.

I hope this solves the problems with crashing in Conquer. (After refreshing your browser cache.) If not, let me know.

Well, it seems to me it should be quite obvious that the Queen's Gambit, or From's Gambit should not be considered chess variants. So I don't see any reason why this No-Castling Chess (not to be confused with the No-Castling Chess that has existed for many decades on servers like FICS and ICS, which is a shuffle variant) should be considered one. It doesn't bring anything new compared to orthodox Chess, much unlike Capablanca Chess, which is totally different in character, and the indeed more dubious case of Chess960, where at least most initial positions are not reachable from the FIDE position, so that it makes sense to have a separate server for it. But this No-Castle Chess can already be played on any server in the world that features normal Chess, most of them far better than Game Courier.

In any case it seems that the SAN generator should be fixed to handle this game, as it appears to mistake many moves for castlings...

But now that I have a position I can look in detail what causes the crash.

I suppose extension should be easy. The point is that the betza parser already considers orthogonal and diagonal moves one family. So rather than splitting up K into W and F by some preprocessing, it considers W and F a form of K with a different (incomplete) default direction set. So apart from the different interpretation of the directional modifiers and the default for it, they would all be considered moves with a (0,1) step, (even F!), yet to be (pseudo-)rotated in several orientations as specified by the direction set. Encountering an X suffix at that point would increase that step to (0,4). In fact KX already works now! It is just a matter of also recognizing S and T as atoms with radial symmetry, and step (0,2) or (0,3), respectively. Then the SX and TX come for free.

[Edit] OK, I added the S and T atoms in both betza.js and betzaNew.js. I must fix the Spiral-Chess Diagram now, though, as I represented the spiral move as S there, counting on the Diagram script ignoring that. But now it would give the King an extra Alibaba move...

The u is in the right place; unloading occurs on the start square of the move, unlike the other mode modifiers, which specify a condition on the destination.

I suppose I must still make the preprocessor that handles the bracket notation recognize the S and T, though; in translation to normal XBetza every leg in your move would have to be expressed in K steps, and it must know how many.

[Edit] OK, the S and T should now also work in the bracket notation as first leg, when a step or slide follows. Like K it works in a bit of a kludgy way; it determines the range of the leap, but the symmetry is actually determined by the atom in the second leg. So if you used K there, it would already have interpreted and A, D, G or H as if they were S or T. Based on the reasoning that if the first leg was a 4-fold atom, no matter how you bend, you would always know whether the next leg is orthogonal or diagonal, and use the corresponding 4-fold atom there rather than K.

Using X in the first leg of a bracket notation does not work yet.

KY is not supposed to work. I can find no logical meaning for it. Oblique moves already are 8-fold symmetric, and you can make all such move sets by extending the regular 4-fold atoms. To extend the radial 8-fold atoms to larger distance the X is already enough.

OK, you are right about the promotion, although the effect of that would (especially in Seirawan Chess) be very minimal.

You cannot get to a position with castling rights in No-Castling Chess, but you can get to a position as would be reached after castling. In orthodox Chess castling rights are not preserved forever, and usually expire when most material is still on the board. All positions that follow would also be reachable from the No-Castling initial position. But the point was really the other way around: that the No-Castling initial position could be reached from the FIDE setup. Not in the way you mention, because you could not get the Pawns back on 2nd rank, but by Nf3-Rg1-Rh1-Ng1 (repeated for the other three Rooks).

That some moves in this opening line are sub-optimal is not really relevant. In fact all opening lines but one must have sub-optimal moves in them, in Chess. The whole idea of thematic tournaments is that you want people to play from positions they would not reach voluntarily. In computer matches one often intentionally uses opening lines that are very poor for one of the players, bringing them on the edge of losing, before the engines are allowed to play the moves of their choice. And then play a pair of games with reversed colors to make it fair. This to eliminate the draw margin, which by the standards of modern engine play is so wide that virtually all games starting from an equal position end as draws. By starting on the edge the outcome can go either way (draw or loss), with about 50% chance, and a reversed pair of games has only 50% probability of ending in a draw, between equal players.

So no, poor quality of an opening line does not make a game where that opening line was played a chess variant.

Where is the Diagram you played this with? In your screenshot the board has 9 files, but the Diagrams in Conquer and Conquer II only have 8 files...