Jordus, you attributed quote to wrong person.

I agree with DrStraw. Suicide is logically impossible because a group can't have zero liberties. It's that simple.

Your description of what a play is doesn't describe Go the way it is normally played (though it does sound a lot like New Zealand rules).
The way Go is usually played is actually more simple. A play is

• placing a stone on an empty intersection, then
• removing all opposing stones that have no liberties, if any.

"Removing all own stones" is not a step in the traditional game of Go. It is something New Zealand rules introduced for the sake of being cute and simple. It is a clever trick, and I admire its cleverness. But I don't like it. It reminds me of those mathematical proofs where instead of doing three obvious steps you do one step which makes no sense, yet, by magic, everything simplifies and the problem is solved. Such proofs are cute but not helpful.

You forgot the third step when suicide is forbidden: backtracking. A play then is

• placing a stone on an empty intersection, then
• removing all opposing stones that have no liberties, if any, but
• not allowed if there would now be any own stones that have no liberties (you have to choose a different intersection initially).

Tradition is not the only source of go rules. Traditional rules have evolved, and they have changed in sometimes surprising ways. There was a different perception of how the rules work in the 19th century than in the beginning of the 20th century, and in turn different than in the middle of the 20th century and even in turn than in the end of the 20th century. There were times when people actually thought a moonshine ko could be alive. The Go rules are not invented, but discovered, and tradition is not adoration of the ashes, but passing on the fire.

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A good system naturally covers all corner cases without further effort.

There's no "backtracking" because that's actually the zeroth step - you verify the legality of your move before you make it. Verifying that a move is legal before making it is a natural part of the game (allowing suicide doesn't get rid of this step). Taking off your own stones is not. You'd have to stretch across the whole board to drop them into the opponent's lid!

When you remove the opponent's stone you gain them as captured stones, which count in your favor at the end of the game. If you remove your own stones what happens to them? You are the one who removed them not the opponent. So you have two options:

1) Stones with no liberties are removed, sometimes going to the person doing the removing and at other times going to the opponent of the one doing the removing.
2) Stones with no liberties are removed, sometimes being removed by the person making the move and at other times by the opponent of the one making the move.

Neither option is elegant. Go is all about elegance. Inelegant rules such as these have no place.

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Still officially AGA 5d but I play so irregularly these days that I am probably only 3d or 4d over the board (but hopefully still 5d in terms of knowledge, theory and the ability to contribute).

Which lid I put the stones in should really make no difference in "elegance". Besides, suicide is in all but very rare situations just a bad move, so in the event of a player playing such a move, unusual motions are appropriate.

I think that forbidding suicide is just a needless restriction, even if most of the time that restriction only prevents bad moves.

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A good system naturally covers all corner cases without further effort.

Elegance is a rather subjective term, I can completely understand people considering suicide inelegant. I suppose I consider it that way myself.

I'm well aware that there are perfectly good rulesets allowing suicide, but its forbidding is not a 'needless restriction' to me. Since there is no obvious reason to allow or disallow it (other than perhaps this subjective 'elegance' which I agree with), it's just a choice whether to allow it or not. A set of rules to allow a player to capture his own stones is a needless addition just as much as disallowing this act is a needless restriction. But you have to choose one, as a necessary clarification.

If we come from a different way, the two choices present themselves like this:

Axiom: There can never be stones without liberties on the board.

No suicide: If a play of one player causes stones of the opposing player to be without liberty, those stones are removed. If a play of one player would cause only own stones to be without liberty, that move is illegal.

Suicide: If a play causes stones to be without liberty, they are removed. Removing opposing stones takes precedence.

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A good system naturally covers all corner cases without further effort.

How about this?

Axiom: After a play there can never be a stone without a liberty on the board.

No suicide: If placing a stone on a point causes an opposing stone to have no liberty, all such stones are removed.

Suicide: If placing as stone on a point causes a stone to have no liberty, all such opposing stones are removed. After that, all stones without a liberty are removed.

----

I think that rules that allow suicide are more complex than rules that do not.

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The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

This is a fascinating debate (and a civil one at that).

I think both sides have some good points, and I'd really like to see a group of professionals (say 5-9) from different countries opine.

With respect, your "no suicide" rule is incomplete. It doesn't define what happens to a placed stone ending up with no liberties. And Harlequin's suicide is in fact shorter and less complex than your example.

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To sig or not to sig, that is the question.

Let's have a look at the Japanese Rules, which do not mention "suicide" at all.

Article 5 (capture) of the 1989 (edited) ruleset claims that the player, who has taken the last liberty of one or more opponent's stones with his move, must take these opponent's stones off the board. The "move" is completed after the removal. So there is NO coexistence of both colour's stones with no liberties.

Combined with the last sentence of article 4 (stones that may exist on the board) - quoted by DrStraw - it goes without saying that you are not allowed to make a move, which takes the last liberty only of your own stone(s).
By the way: If you ever would, these stone(s) must remain on the board. You are not allowed to take them off the board, because they do not belong to your opponent's stones. And your opponent is not allowed to remove them, because he did not make the last move.

In other words you might say that a player must never do something, which colloquially is called "suicide".

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The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

Sure it does. The axiom says that placing a stone so that it ends up with no liberty is not a (legal) play.



It is also inaccurate. Harleqin's first language is not English, I think.



There is a simple English interpretation that says that if a play causes stones of both players to be without a liberty, all the stones without liberty are removed. (That is within the meaning of the first sentence.) The opponent's stones are removed first. (That accords with one meaning of precedence. )

Edit: Deleted inaccurate statement.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

I have to admit that I tried to make the text more compact at the cost of precision. Your version is better.

I think that your "no suicide" is lacking explicitness. The fact that the japanese rule text does it in a similar manner indicates to me that actual tradition is not to think at all about suicide.

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A good system naturally covers all corner cases without further effort.

In the "Suicide case", the axiom is pointless and can be left out, as it is always true as a result of the rules. In the "No suicide" case, it is required.

I think either case can be written roughly equally elegantly and concisely, and neither option is really more complex than the other.

The Japanese Kanji used in the books for something like "to play a stone" is 打. It's original meaning is "to hit", "to strike".

It's left part is 手, what means "hand"; it's right part is 丁, what means "nail".

So the Kanji gives an idea of "something to be struck (with the hand)".

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

着手 are the Kanji in the rules. The second one means a play. The first one has a meaning of putting, fixing, or attaching, which seems like the operative one.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

Actually, I was following you.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.

着 litarally means "arrival" or "clothes". The latter surely has something to do with "attaching". So the meaning may be something like "the hand that attaches" (a stone to the board).

In a Japanese book, where I found the rules in Japanese, 着手 is explained as 石を置く, what means "to put a stone in place".

_________________
The really most difficult Go problem ever: https://igohatsuyoron120.de/index.htm
Igo Hatsuyōron #120 (really solved by KataGo)

If you want it even simpler:

1. Place a stone on the board
2. Remove any opposing stones without liberties.

With these rules, not only is suicide allowed, but the stone(s) placed into suicide will actually remain on the board! Any such stones will then be removed by step 2 of the opponent's next move!

(Yes, this means you can kill some groups that could otherwise not be killed, but the same is true for the current "suicide" vs. "no suicide" rules. It is a valid set of rules )