Comments by GerdDegens

"Could a Bishop move from d1 to e8 along the path d1-c2-b3-a4/4-b5-c6-d7-e8?" (a4/4 is a typo, h5/5 is correct)

Yes, that is possible, but only in two moves. The first move goes up to square 5 and in another move up to e8. It's like normal chess. The bishop started from a white diagonal and after a second move the bishop stands on a 'black' diagonal. This means a color transfer (Color Change or whatever is correct) has taken place.

"Assuming ‘d4’ is a typo for ‘a4’, then my reading of the rules agrees that it could indeed take this path, or instead a path d1–e2–f3–g4–5–g6–f7–e8."

The path d1–e2–f3–g4–5–g6–f7–e8 is absolutely correct - but in two moves. Move 1 via d1-e2-f3-g4 to square 5, then move 2 via g6-f7 to square e8.

"And so e.g. a rook can checkmate a king on h8 from h1, h2, h3, or h4, but not h5 or 5?"

That's not according to the rules. Correct is: a rook can checkmate a king on h1 from h8, h7, h6, but not from h5 or 5.

The parallel situation looks like this: a rook can checkmate a king on a8 from a1, a2, a3, but not from 4 or a4.

I have indeed trouble with your question. I don't understand how "B b4-b3" or "B b3-b5" has anything to do with a bishop's moves.

I want to answer your question like this and hope that I'm on the right track. You ask what a bishop can do with one move.

Let's start from d1. The bishop can move to the left via c2-b3-a4 to square a5. The following move is also possible: d1 via c2-b3 to square 4. From there, the color change takes place in a second move by reaching the squares b5-c6-d7 to e8. To the right, the bishop can go to square 5, via e2-f3-g4.

If you think that's an asymmetry, then that's the result of the new board geometry. The opponent has the mirrored move options and thus equal opportunities.

Did I understand and answer your question correctly?

Thanks for your explanations, I didn't know that. This abbreviated notation makes sense.

The moves "B b5-b3" and "B b3-b5" you mentioned as examples are not legal moves in my variant. With the exception of the rules for the new squares 4 and 5 and for the switches 4/a4 and h5/5, the FIDE rules are valid exclusively.

"Let's say a bishop is on a4/4."

Let me be specific: a bishop doesn't stand on a4/4; he stands either on 4 or a4. The player must clearly mark the location.

If the bishop is on 4, then his path goes via b5, c6, d7 to e8. In the other direction it goes via b3, c2 to d1.

If the bishop is on a4, then he can choose; he can go down to d1 as before. He can move upwards to a5 in a first move, to go via b6, c7 to d8 in a second move. The other option is to move to f8 via c5, d6, e7.

There are no other move-options.

"Whenever a move passes through a4 from below, it can be continued normally, or like the upper board half was not shifted."

That is correct!

"a4' cannot be reached from below."

Of course, a4' (I'll call it 4) can be reached from below. For example, if you start from d1, you can reach the switch 4/a4 upwards. The player must then decide whether to occupy square 4 or square a4 and mark this clearly through his positioning. After that he either stands on 4 or on a4. Then the player can proceed as described in the reply to Fergus Duniho.

"Can a Rook move through a switch on a single move?" Yes, of course. Otherwise, a rook on a1 could not checkmate a king on a8 in one move.

R a1-a8 = legal; R a1-b8 = legal; R a8-a1 = legal; R b8-a1 = legal

"What I meant is that a4' cannot be reached from a3."

Why not? A rook, pawn or queen starting from a3 and occupying the switch must decide which square of the switch is to occupy - 4 or a4.

"a move into the lower board half would always look as if you started from a4."

That's not true: A rook on a8 that wants to move to the lower half of the board can occupy square 4, but not a4. A rook on b8 can occupy a4, but not 4. Incidentally, in this direction the distinction between 4/a4 makes no sense for a rook (or queen). The switch only works in one direction. Either from the lower half of the board starting from a1, a2, a3, or from the upper half of the board starting from h8, h7, h6.

May I refer to an earlier answer, which I hope answers your question:

"Let's say a bishop is on a4/4."

Let me be specific: a bishop doesn't stand on a4/4; he stands either on 4 or a4. The player must clearly mark the location.

If the bishop is on 4, then his path goes via b5, c6, d7 to e8. In the other direction it goes via b3, c2 to d1.

If the bishop is on a4, then he can choose; he can go down to d1 as before. He can move upwards to a5 in a first move, to go via b6, c7 to d8 in a second move. The other option is to move to f8 via c5, d6, e7.

There are no other move-options.

If I may summarize from my point of view:

I gather from the comments that my version is not easy to understand. But that's not a disadvantage a priori. It remains to be seen whether the possibility of checkmating the king with just one piece will play a role in chess. The same applies to the bishop, who can now change his color diagonal.

But if I see it correctly, then there are no bugs in the variant and the set of rules is consistent. Complicated, yes, but conclusive.

Let me emphasize again: A change between 4 on a4 or h5 and 5 is not possible.

Some examples.

Bischoff on d1 to the left:

Standing on a4 after the move, a color transfer is not possible. Standing on 4 after the move, then a color transfer is possible. Because from there you can continue in the next move via b5, c6 etc., a color change has taken place.

Bishop on d1 to the right:

The move can go up to 5 (and not h5, this square cannot be occupied). The next move can be continued via g6, f7 etc. There has also been a color change.

For the other half of the board everything is vice versa.

Does that answer your question?

I had already answered that before, as follows:

A rook/queen on the rank 4 can only occupy square a4 and not square 4. This applies to the switch h5/5 vice versa.

"So, I gather that the following are all legal moves:

B d1-4, B 4-d1, B e8-5, B 5-e8"

That is absolutely correct.

"So, it looks like the diagonal from 4 to the first rank is a different color than 4, and the diagonal that goes from 5 to the last rank is a different color than 5, and that is how the color changing is done."

By the way: The squares 4 and 5 do not have a uniform color. The squares are each composed of both colors. This is the only way to make a color change possible.

Dear En Bw, thank you for your comment, which is absolutely correct.

I don't think that the moves to a5 and b5 are legal since they are on the same line. Merging the squares 4 and a4 would not change that. On the contrary, the possibility of being able to detect movements on the same line or the same diagonal would be diluted.

8. N c5-A4

According to my definition, the switch can only be operated from 'below'. After that, the move N c5-A4 would not be possible. N d5-a4 would be possible. However, in my reply to Bn Em I proposed an extension of my definition.

17. N a4-c3 ---> N a4-c2

18. N f5-c4 ---> N f5-d4

"En Bw" - sorry, won't happen again.

"That's interesting; given that a rook is allowed to move sideways from 4 onto b4 and beyond, that means that a rook on 4 can threaten a rook on b4 without being attacked back. Is this intentional?"

That doesn't seem logical indeed.

Assuming a rook is on 4 and an opponent's rook is on e4, my definition means that the rook on 4 can attack the rook on e4, but the reverse is not possible. That's inconsistent. It is probably appropriate to add that the switch can be operated not only from 'below' but also from the side. This would eliminate the inconsistency.

The moves B a4–c2; R a6–4 are legal moves, they are conform to the rules.

Move 17: N a4-c3 doesn't seem legal, but N a4-c2 would be legal.

Move 25: N f5-c4 doesn't seem legal in same way, but N f5-d4 would be legal again.

You can agree on almost everything, certainly to make the game playable and programmable. Regardless of that, I can only say my point of view and describe my intentions.

"A switch is an overlapping pair of spaces that in some ways operate together as a single space."

From my point of view it looks different. The square a4 of a switch is an independent square and is completely identical to the square a4 in normal chess. 4 (A4) is a composite square consisting of a half and triangle part of a4 and the new triangle due to board geometry. The new square 4 (A4) gets the same play options as all squares of the game board - 4 (A4) is considered equal.

This means that the squares a4/4 (A4) must first be seen independently. These independent fields get an additional function when they work together and act as a switch, as described.

My intention is therefore not compatible with the proposal to merge fields 4/a4 (A4) as proposed by Jean-Louis.

It is possible to agree on the sides from which the switch should be accessible. We have clarified access from below and from the side, access from above is also not a problem and is already part of my proposal. The only question is whether it is access to the switch as a unit or to the individual square of a switch. According to my intention, the second applies.

"Allow pieces access to the spaces of a switch from any direction, and when a piece moves to a switch, allow capture of any piece on the switch even if the capturing piece moves to the other space. For example, if a bishop is on A4, and a Rook moves to a4, consider the Bishop on A4 to be captured."

As described, access to the switch from all sides is not a problem. It is possible to agree on the proposal, but it does not fit my intention. However, if the game becomes more playable and programmable - so what.

To the Knight: I can't allow anything here, but I can say what my point of view is. If we stick to the fact that the squares of a switch should be seen separately, then knight moves ending on the same line are not possible. However, as the game becomes more playable and programmable, compromises should be possible.

"One last rule change I would suggest is to let Rooks, Queens, and Kings use their ability to move horizontally to switch between the spaces constituting the switch. This would basically involve lifting one more restriction on movement to the spaces making up a switch. "

I have problems with that. I have emphasized that the squares of a switch represent independent squares. This would rather mean that moves between the squares of a switch are possible. The independence of the squares on the one hand and the functionality of a switch on the other compete with each other. Regarding the direct change between the squares of a switch, I tend towards the superordinate function, so a direct change should not be possible. At least that's my intention. But here, too, compromises determine reality.