Please fix default NZ rules komi for ranked 9x9 and 13x13

[gennan]

@BHydden

Obviously 1 hc stone is worth komi… what isn’t known is how much komi should be given to fairly compensate 2-9 stones

Maybe it’s not known exactly, but it’s not a complete mystery.

The formula V = (H * 2 - 1) * K seems to be a reasonable estimate (H = number of handicap stones, K = fair even game komi ~ 6.5 points, V = equivalent point value of the stones handicap). I think it’s good enough to be used by a rating system.

[teapoweredrobot]

Also @Samraku for a lot of work on calculating the correct value of reverse Komi

Score-based rating algorithm? (estimate score difference between 2 players)

Also https://senseis.xmp.net/?PointsRatingSystem

There was also this request:

Reverse komi to be rated

For one side, handicap games can be rated on OGS. For another side many players on OGS don’t like to play with handicap. But if you want to use a reverse komi your game will not be rated So I ask myself, why couldn’t we have a reverse komi system and rated? By extension, could we bid the komi (pie system, one propose the komi, other chose the color) and same, integrate the pie system for rated games?

[_KoBa]

By a random sidenote, i’ve been asking reverse komi for handicap setting automated for years now, it would be great addition on ogs and i’m sure many people would love having reverse komi as an automated and ranked option. Give us reverse komi!!

On a bit more to the NZ rules and komi… Yeah it too requires fixing, the way NZ rules is implemented here is just incorrect. >___>
@anoek i know you have lot on your hands, but could NZ rules be soon fixed for correct komi and jigos being possible? And maybe slip ‘reverse komi’ as proper handicap option?

[_KoBa]

I dont think komi on smaller boards is specified by some official NZ rules, but according to new zealand go society the following rules should apply:

" In an even game, 7 points (komi) are added to the white players territory.

In a handicap game, white passes the first n - 1 moves where n is the size of the handicap. There is no komi.

Go can be played on different sized boards than 19 x 19 with a corresponding different number of stones. 9x9 boards are often used for fast games or by learners.

The size of the handicap is up to the players concerned or the tournament director but where both players have NZGS ratings the best handicap is the difference of their ratings rounded up to a whole number. If the difference is less that 0.5 they may also choose to play an even game."

So komi of 7 in all even games, 0 if there is handicap. Board size doesnt matter. Unless players (or TD in a tournament) choose something else.

[anoek]

Once I get past my currenty fires I can cycle to that. When I get there though we should also take that opportunity to fix the 9x9 and 13x13 handicap/komi progression, they’re based on the Old Japanese Recommendation which decidedly sucks, however it’s going to take some notable exploration to find a proper progression.

[dragon-devourer]

KataGo analysis has already been done and reported here:

https://lifein19x19.com/viewtopic.php?f=15&t=17750

Our own friend @gennan nicely summaries the situation in a reply on that L19 topic:

@gennan

for odd board sizes 9-19, the fairest komi is 6+ for Japanese rules and 7- for Chinese rules.

With Japanese rules, 6 komi looks like perfect komi.
When draws are unacceptable, 6.5 komi looks like the fairest alternative (but then white has an advantage on smaller boards).

With Chinese rules, 7 komi looks like perfect komi.
When draws are unacceptable, 6.5 komi looks like the fairest alternative (but then black has an advantage, more so on smaller boards).

[Feijoa]

@anoek

we should also take that opportunity to fix the 9x9 and 13x13 handicap/komi progression, they’re based on the Old Japanese Recommendation which decidedly sucks, however it’s going to take some notable exploration to find a proper progression.

That would be great! The current thing is really weird (here’s my guess about the details), especially since it is limited to one specific komi value for each handicap, so not even the complete “old Japanese recommendation”.

That means, for example, that there’s not much of a handicap on 9x9 until you reach a 5-stone difference. A 5.9k playing a 1.0k has to play with no extra stones and 3.5 komi!

I think a few people on the forums have posted good handicap tables for small boards; anything that’s actually in use in a real club anywhere is probably a lot better than what we have now.

[Groin]

Today it seems there should be a real fundamental debate about komi. Should we follow the old japanese recommendation or should we follow AI with his high value fixed komi?

I would like to hear what today pros think about it and if the AI suggestion fit the ama world.

[anoek]

I do know our own black win rates under the old Japanese recommendation are pretty bad for 9x9 and 13x13, so there’s definitely room for improvement. Using an AI suggestion seems like a solid potential, but I haven’t dove into the subject enough to feel confident in saying what is right - I just know that the old Japanese recommendation is not very good.

[_KoBa]

Why would you use what ai thinks instead using the komi-values specified for different rules? Afterall ogs is offering bunch of different rulesets for games instead having some “ogs rules” like pandanet. For example NZ rules say that komi should be 7 on even games and 0 on handicap games, no mention about having exceptions for smaller or larger boards.

[shinuito]

I think “where does it say the Komi has to be 7” is the question.

@anoek

Has that been specified in the NZ rules somewhere?

While the Senseis library page says something about 7 Komi on 19x19, I don’t think it says something about other board sizes?

I guess this I supposed to be the official source

New Zealand Rules of Go

Go is played on a board with a 19 x 19 grid, by two players, one using a set of (about) 180 white counters, the other a set of (about) 181 black counters. These counters are called stones.

In an even game, 7 points (komi) are added to the white players territory.

In a handicap game, white passes the first n - 1 moves where n is the size of the handicap. There is no komi.

Later it does say

Go can be played on different sized boards than 19 x 19 with a corresponding different number of stones. 9x9 boards are often used for fast games or by learners.

and while it doesn’t seem to explicitly seem to say anything about Komi in general it’s probably implied that 7 is for even games. Diagram 4 is a 9x9 board

This was an even game so we add seven points to white and see that white has fourteen points more than black; thus white is the winner.

So I guess it would be fair to interpret the Komi to be 7 on other board sizes.

[Maharani]

Bumpity…