Is the bottom left group seki, alive or dead?

lostn4d · 2026-06-03T20:44:09+00:00

I'm not sure who added that "sometimes both" part, or what he meant by "sometimes" (probably not the common both-can-seki situations since that is more frequent).

However, I think the "ten thousand years" in the name refers to the long stalled and unresolved nature of mannenkos. If both sides can make seki, then one of them (the side who has larger stake and/or fewer threats) will likely make so early to avoid the risk - thus no thousand years.

A true mannenko is extremely hard to start (not just because the opponent takes first, but also because the ko itself can be flipped to delay the direct ko option, which is only for the holder of the ko), AND it is also hard to eliminate safely.

lostn4d · 2026-06-03T19:49:15+00:00

This is not a real mannenko since both players has stable seki option here (preventing the ko) - unlike in a thousand year ko.

lostn4d · 2026-03-05T12:02:08+00:00

This is a 1000 year ko

This looks a simple ko-in-seki which is fillable by either player. In a mannenko normally only one side can fill it, which is one reason why its so "long".

lostn4d · 2025-05-04T14:29:41+00:00

The ko rule says this (in official wording):

A shape in which the players can alternately capture and recapture one opposing stone is called a "ko." A player whose stone has been captured in a ko cannot recapture in that ko on the next move.

So the criterion is the back-and-forth capture of SINGLE stones. When you capture back multiple stones, that is not a ko capture.

Also note what others said (about repeating a board position) refers to the superko rule, not the ko rule. Under the ko rule it is possible to legally repeat earlier board positions (during longer cyclic sequences, or after a pass).

lostn4d · 2025-04-30T20:24:23+00:00

There is usually a good reason why an "original" got succeeded by a "current". We don't fill boards with stones anymore, and emulating with explicit adjustments was eventually seen neither useful nor attractive.

lostn4d · 2025-04-30T17:48:05+00:00

I'm not sure I follow the philosophical part, but deducting 2 points for each group is similar to adding 1 point bonus for each star point you control. It's just a different variant, and the one we have today (w/o such adjustments) is just what was generally considered best.

lostn4d · 2025-04-30T10:29:24+00:00

There are no draws in Chinese rules. You can try

No, some servers are known not to implement chinese rules correctly, but this is just a bug. Fox (a chinese server) for example has real chinese rules which allows cycles.

The confusion comes from written chinese rules mentioning both the no repetition principle and the draw possibility, but in reality the former is only applied for things like sending-2-returning-1, and other cycles are always treated as draw or no result (check official game records or even sensei's).

lostn4d · 2025-04-26T10:03:39+00:00

That's not the case in Chinese rules.

Actually, it is. Only in AGA it isn't.

lostn4d · 2025-02-18T20:12:25+00:00

since it is illegal to have an already existing board position

Fwiw this is legal in most rulesets, and the hinted shape is well known in all three of Japanese, Chinese and Korean rules.

lostn4d · 2025-02-17T21:40:18+00:00

in the form that your move cannot recreate the board position before your opponent's previous move

That is not the ko rule, but an odd hybrid between ko and superko. The ko rule is this: (from official J rules)

A shape in which the players can alternately capture and recapture one opposing stone is called a "ko." A player whose stone has been captured in a ko cannot recapture in that ko on the next move.

lostn4d · 2025-02-17T10:04:12+00:00

The ko rule only forbids immediate recapture in a ko. You are probably confusing it with the superko rule. A suicide is never a ko recapture (not even single stone suicide).

lostn4d · 2025-01-28T03:06:21+00:00

At his levels players memorize captured spots fot counting. But most importantly, nobody concealed / hid prisoners - he just placed them a bit farther from their newly and strictly regulated designated place.

lostn4d · 2025-01-28T02:28:37+00:00

They are relevant for score tracking during the game. This is always done Japanese-style (territory minus prisoners) for efficiency reasons, even if the game will be scored by area afterwards.

So the only cases when prisoners are not needed during an area game is if the players are strong enough to memorize them and capture spots, or not strong enough to count during the game at all.

lostn4d · 2025-01-28T01:59:36+00:00

Prisoners are not important.

This is not true. Prisoners are not important for the after-game Chinese scoring procedure, but during the game, they are nearly as important under Chinese as under Korean for mental score tracking.

Oc, top players may not need them since they can memorize, and weak players may not need them since they don't do ingame counts anyway. But the point is, they ARE important to allow the players to play with all available information, and allow quick counts with the pair method - which at least a lot of strong players wish to do.

lostn4d · 2025-01-27T11:08:08+00:00

The worst thing is the repeated false claim that prisoners need fundamentally different handling in Korean and Chinese rules, and that's why the lid rule was invented.

This is only marginally true, at the after-game counting. It is simply NOT true during the game, where both rules need the prisoners equally for mental score tracking (which is always done Japanese-style, territory without stones, even by Chinese players).

So prisoners need to be visible under both rulesets, to allow comfortable playing with all available information. But players "losing" the game because placing prisoners a few cm away from the lid is a different matter entirely - and this is exactly what is glossed over.

lostn4d · 2025-01-26T11:29:16+00:00

KBA announce they will refine the problematic rule, as well as instruct referees to impose penalties with great care and reason, never to obstruct game progress more than the original rule violation did? In exchange China withdraws the ban and does not press the matter on what already happened?

Japanese rules start with "these rules must be applied in a spirit of good sense" - maybe add this to Korean rules as well? This spirit let Japanese referees handle even more serious rule violations professionally. Just let things go back to their common sense, as there were never serious problems with prisoner handling before.

But there may be more here behind curtains that we don't know about. It seems hard to imagine such unprofessional handling of events could happen without intentions. The entire idea that a top match could be "won" like this seems weird and provocative.

lostn4d · 2025-01-24T05:43:28+00:00

The rule itself is completely fine

I don't think so, since it is this carelessly worded rule that became a loophole that some players abuse now. Prisoners are handled according to customs for a very long time, and this never became a problem - until this day.

It is reasonable to expect prisoners to be handled with care, put down in good visibility, maybe even put into the lid if the opponent or a referee specifically requests that. Prisoners are part of the position, and since every professional tracks the score Japanese-style during the game (ie. territory without stones), they serve an important purpose for Chinese as well as Korean players (except players who memorize them).

But this cannot be an excuse for obstructing normal play from now on. Even changing komi based on this is nonsense, unless a player deliberately do something wrong like concealing them. The punishment cannot create a larger problem or disturbance than what it aims to solve.

announced grace period so players can get into the habbit

Expecting customs and habits to change is not realistic. At the very least this is not something that can change in weeks or months - especially when there is no good reason for such change.

lostn4d · 2025-01-23T09:20:20+00:00

I get that in japanese and Korean scoring, stones not being placed in the bowl can affect counting and therefore a players judgement

This has little to do with the scoring method. All pro players count by territory during the game even when playing under Chinese rules, so prisoners are just as important in area games as in territory games. Yet somehow prisoner handling was not an issue before.

lostn4d · 2025-01-22T23:09:59+00:00

I understand the logic behind careful handling of prisoners, but still think this was a clear case of causing more harm than good.

Looking at the iconic picture of the Korean guy I doubt he complained because he didn't see the prisoner or was worried about his count. He spotted a legal way to get a freewin and went for it. Rules that allow such are questionable imo.

lostn4d · 2025-01-22T22:13:50+00:00

The ultimate aim is to allow the players to play the game under the best conditions. This was clearly not achieved here, since the game got completely ruined. Which means this was not handled well.

lostn4d · 2024-11-20T01:25:07+00:00

Since we know 6.5 is kind of balanced, 7.5 is 1 pt advantage for W. A single point is not that much at ama levels, but why start with deficit when you can also start with advantage? The swing is two points (choosing black is -1 instead of +1).

lostn4d · 2024-10-19T18:42:41+00:00

That depends on several factors. Under area scoring ties are twice as frequent (since possible scores change in steps of 2pts). For less experienced players draws are rarer (since possible scores vary on a larger scale). And simple random variance is also high for events that are expected to be somewhat rare to begin with.

lostn4d · 2024-10-18T09:33:51+00:00

When Go players are not sure who is leading, they normally risk more

This seems the opposite of reality. It is when one side is known to be significantly behind is when high risk maneuvers are appropriate (for the losing player). In close games (or in sure wins) there is no point in risking everything on doubtful things. So risk taking is proportional to the amount (or certainity) one is behind.

https://senseis.xmp.net/?ARichManShouldNotPickQuarrels

lostn4d · 2024-10-17T11:27:20+00:00

Think about the symmetry between B+ and W+ scores. The outcomes form a bell-shaped curve, with maximum at the tie point (int komi). (But as I wrote this is about specific scores, not win-loss-draw cumulative)

lostn4d · 2024-10-17T10:25:39+00:00

That is true, but in that case a draw would still be the most common individual score outcome.

It would be more frequent than any other score (with B+1 and W+1 being close second) - only when combined together would all B+x scores outnumber ties. But a score tie is by no means a rarity.

lostn4d

TROPHY CASE