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Checkmating Applet. Practice your checkmating skill with fairy pieces.[All Comments] [Add Comment or Rating]
Aurelian Florea wrote on 2022-05-23 UTC

Thanks once again for the insight!


H. G. Muller wrote on 2022-05-23 UTC

There is one caveat: R2 (and WD) lose their mating potential on 12x12. Adding Camel moves cures this, even up to 16x16 (the largest the Applet can do). So I have little doubt R2-then-B would have mating potential there.

For B2-then-R very large boards actually make it easier. Because from a large distance you could use the R legs as if the piece were a Rook. Even an invulnerable one, because the bare King cannot approach it. And the F step can be used to tighten the noose around the bare King. So it should be a very easy checkmate.


Kamikaze Mortal Shogi. Send your Kamikazes on suicide missions in this Shogi variant. (9x9, Cells: 81) [All Comments] [Add Comment or Rating]
H. G. Muller wrote on 2022-05-23 UTC

My guess is that forbidding kings to face each other would not help. Exposed kings get checkmated very quickly in Shogi. So when the manage to cross it is always surrounded by a group of friendly pieces, from which they are chased out, and then again get new pieces dropped around the to survive.

I could imagine that the Kamikazes present the same problem as Pawns, when you are allowed to drop more than one of those in the same file.


Fergus Duniho wrote on 2022-05-22 UTC

Ever since I played a game with Greg that ended in an impasse, I felt this game may be too drawish, and I've sometimes considered changing the rules to fix this. The rule change I was thinking of was to forbid Kings from crossing to the other side of the board and to give them the ability to check each other from a distance, as in Eurasian Chess. However, it has come up that Shogi has its own rule for handling impasses, and there are alternatives to it.

The rule in Shogi is if each King has moved to the opponent's camp, which is the ranks the opponent's pieces start on, players may agree that an impasse has been reached and count pieces to determine the winner. Kings count for nothing, Rook and Bishops, promoted or not, each count 5, and other pieces each count 1. A player with less than 24 points loses. Because of the piece attrition in Kamikaze Mortal Shogi, it is possible that each side would have less than 24 points. So, instead, it could be played with the rule that whoever has more points wins. But I don't like this counting solution, and others don't too.

An alternative rule proposed for Shogi is called the Try rule. This involves winning by moving one's own King to the space the opponent's King began on. I don't know if this involves moving there only if it is safe or if it becomes a condition only after both Kings have crossed into the enemy camp. I would propose making it a winning condition only if both Kings have crossed into the opponent's camp and it moves there safely.

Similar to this is the Campmate rule, which allows a player to win by reaching the last rank with his King. I would propose the same conditions on it that I am proposing for the Try rule.

Another possibility for dealing with impasse is to reverse the directions that the opponent's pieces may move when the King moves into the opponent's camp. Additionally, pieces could be allowed to treat their own camp as a promotion zone when the opponent's King is there. These changes would discourage players from moving their Kings to the other side of the board without strictly forbidding it.

One more possibility is to allow Kings to check each other from a distance but to not forbid Kings from crossing to the other side. Instead, the ability of Kings to check each other from a distance would usually prevent both Kings from crossing to the other side, and if they happened to do so by having another piece between them on the same rank, this ability would provide an incentive for leaving the King more exposed.


Checkmating Applet (3 vs 1). Practice your checkmating skill with fairy pieces.[All Comments] [Add Comment or Rating]
H. G. Muller wrote on 2022-05-22 UTC

Good catch. This problem surfaced everywhere after a change in the general Diagram script. I did fix it in most places, but apparently forgot to fix it here. It should work now.

(The reason was that this applet abuses the routine WeirdPromotion, which would be called for every move, to invoke the routine that fetches the best move from the end-game table and play it. But at some point the Diagram script started to call WeirdPromotion twice, also once to figure out whether it should allow the user to choose a piece. This to also support unexpected promotions that involve a choice. So the WeirdPromotion routine included in this applet should be more careful now, and only invoke the routine for playing a move when it has not already been done.)


Parahouse. (Updated!) Shogi + Strong pieces. (9x9, Cells: 81) [All Comments] [Add Comment or Rating]
Fergus Duniho wrote on 2022-05-22 UTC

I see Campmate was mentioned in the comments to that video 5 months ago.


Checkmating Applet. Practice your checkmating skill with fairy pieces.[All Comments] [Add Comment or Rating]
Aurelian Florea wrote on 2022-05-22 UTC

Thanks for the analysis!


Checkmating Applet (3 vs 1). Practice your checkmating skill with fairy pieces.[All Comments] [Add Comment or Rating]
Aurelian Florea wrote on 2022-05-22 UTC

I see another problem. The computer moves twice!


Checkmating Applet. Practice your checkmating skill with fairy pieces.[All Comments] [Add Comment or Rating]
H. G. Muller wrote on 2022-05-22 UTC

Unfortunately it is not very easy to include the bent riders. For one, their retrograde moves are not the same as their normal moves. The current program assumes they are, and uses the same move generator for both. It would also raise the design problem for how to indicate the bent slides.

The current move-definition pane does allow you to define limited-range sliders such as R2, btw. Just define a regular Rook by clicking the W squares twice, and then for each paths click the H square to cut off the slide there. Usually the ability to jump doesn't have much use at this stage of the game; both WD and R2 can force checkmate in the same number of moves. It is just the statistics that changes a bit.

So R2-then-B can certainly force checkmate, as R2 already can. B2Z reaches a subset of the B2-then-R destinations, and it is also able to force checkmate. So I expect the B2-then-R to do it even faster, as the fact that it cannot leap directly to the Z squares should hardly hinder it.


Checkmating Applet (3 vs 1). Practice your checkmating skill with fairy pieces.[All Comments] [Add Comment or Rating]
Aurelian Florea wrote on 2022-05-22 UTC

Yes! That was it!


Parahouse. (Updated!) Shogi + Strong pieces. (9x9, Cells: 81) [All Comments] [Add Comment or Rating]
Fergus Duniho wrote on 2022-05-22 UTC

Here's a video on the Impasse rule. Hidetchi, who made the video, states that he doesn't like this rule, and some people have proposed replacing it with the Try rule, which says that a player can win by moving his King to the position the opponent's King started from. What you're calling Campmate is similar to this rule. Instead of just saying "No Impasse," which is kind of cryptic, you could say, "Instead of the official Shogi rule for resolving an impasse, this game can be won by Campmate, which involves moving the King to a safe space on the last rank."


Checkmating Applet (3 vs 1). Practice your checkmating skill with fairy pieces.[All Comments] [Add Comment or Rating]
H. G. Muller wrote on 2022-05-22 UTC

Because you press the Piece1 or Piece2 buttons only once?


Archchess. Large chess variant from 17th century Italy. (10x10, Cells: 100) [All Comments] [Add Comment or Rating]
Parker KH wrote on 2022-05-22 UTCGood ★★★★

i think so


Parahouse. (Updated!) Shogi + Strong pieces. (9x9, Cells: 81) [All Comments] [Add Comment or Rating]
Daphne Snowmoon wrote on 2022-05-22 UTC

H.G.Miller //

I have spelled out the rules exactly. Is this allowed?


Checkmating Applet. Practice your checkmating skill with fairy pieces.[All Comments] [Add Comment or Rating]
Aurelian Florea wrote on 2022-05-22 UTC

It would be a very nice feature to include bent riders. The gryphon mates but I'm curious for pieces like R2 then bishop and B2 then rook. I think they are both major (WD is major to my knowledge so probably R2 is too, B2 then rook could be trickier).


Checkmating Applet (3 vs 1). Practice your checkmating skill with fairy pieces.[All Comments] [Add Comment or Rating]
Aurelian Florea wrote on 2022-05-22 UTC

Why trying to define pieces I always get capture only pieces?!


Cardinal. Moves as Bishop or as Knight.[All Comments] [Add Comment or Rating]
Aurelian Florea wrote on 2022-05-22 UTC

I have noticed the general method. Thanks!


H. G. Muller wrote on 2022-05-22 UTC

For larger board sizes you can try the general Checkmating Applet, upto 16x16. That also makes it more obvious what the general method is, for driving towards the edge, and then towards the corner.


Aurelian Florea wrote on 2022-05-22 UTC

Ok, thanks. It seems chessV in Grand chess cannot do it with small variantion. It probably does it with none, though! I tried that!


Parahouse. (Updated!) Shogi + Strong pieces. (9x9, Cells: 81) [All Comments] [Add Comment or Rating]
H. G. Muller wrote on 2022-05-22 UTC

I mean that you cannot expect the typical reader to know any of the rules of Shogi. So yes, you would have to fully explain those rules, or at least those that also apply to your game. It makes little sense to explain rules just to say that they don't apply.


Cardinal. Moves as Bishop or as Knight.[All Comments] [Add Comment or Rating]
H. G. Muller wrote on 2022-05-22 UTC

Use the "Try it" link in the Notes section, and start playing for black to see how it is done.


Aurelian Florea wrote on 2022-05-22 UTC

Does this piece and king mate a lone king? How? Is it similar to KNB vs K? Does it work on any rectangular board?


Eight-Stone Chess. Players can move neutral stones as well as pieces.[All Comments] [Add Comment or Rating]
Aurelian Florea wrote on 2022-05-22 UTC

This game is very interesting and it makes an interesting candidate for the interactive diagram. Probably the stones may be somehow implemented by holes. I'm not sure how neutral would be implemented in XBetza, though!


Parahouse. (Updated!) Shogi + Strong pieces. (9x9, Cells: 81) [All Comments] [Add Comment or Rating]
Daphne Snowmoon wrote on 2022-05-22 UTC

H.G.Miller //

Umm, so,

"The rest is the same as Shogi"

Do you mean to explain this sentence in more detail?


H. G. Muller wrote on 2022-05-22 UTC

For example, I don't think Shogi has an "impasse" rule. 

It actually does have such a rule. See for instance the Wikipedia article, which devotes an entire paragraph to it. Like 3-fold repetition impasse (= jishogi in Japanese) is both a game situation and a rule made to specify consequences for when that situation occurs.

It does not make much sense to have detailed explanation of rules that the variant at had does not have. One can doubt the wisdom of using Shogi as a reference. Many articles on CVP of course use orthodox Chess as a reference, and only describe how the variant they discuss deviates from it. But I think 95+% of the visitors of CVP will be quite familiar with orthodox Chess, while to most Shogi would be something as alien as Courier Chess or Metamachy. Even for Fergus, who must know 100 times more about chess variants than the average reader, the current description was not sufficiently clear.

So I would suggest to make a full rather than an incremental description of Parahouse in the Rules section. The current comparison with Shogi is then more suitable for the Notes section. This gets rid of the need to mention Pawn-drop mate and impasse, as Parahouse does not have those rules. It would have to mention that:

  • Pieces mandatorily promote when their move starts or ends within the zone
  • Pieces that are captured demote, change side, and get into the hand of the player that captures them
  • Unpromoted pieces can be dropped from the hand on an empty square, instead of a normal move.
  • Pawns cannot be dropped in a file that already contains one of the same color.
  • The game is won by checkmating or stalemating the opponent.
  • Perpetual checking is a loss for the checking player. (?)
  • Other (?) 3-fold repetitions are a loss for the player that last moved.

All in all that is not much longer than what you there is now.

 


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