Igo Ranks Explanation, Math and Estimation

    Keywords: Theory

Okay, there has been much discussion on the strength of professionals, especially one that play in Europe and frequently play amateurs.

When they sometimes lose, certain people like to basically say that that pro is not a "real" pro.

While I used to consider such speculation about rank a waste of time, time which could better be spent studying go, I have an excuse.

I'm a bit of a math fan so I couldn't pass up the opportunity when I found out how much fun it was (possible scenes of mathematical calculation may proceed-- if you don't like math, look away now. I mean it. Yes. Go on, shoo.)

The System, and What we Know

To help, I'll throw in some martial art belt colours (from which martial art, I don't know):

7 Dan (-6kyu) Full Black Belt

6 Dan (-5kyu) Black Belt with Brown Stripe

5 Dan (-4kyu) Black Belt with Red Stripe

4 Dan (-3Kyu) Black Belt with Blue Stripe

3 Dan (-2kyu) Black Belt with Green Stripe

2 Dan (-1kyu) Black Belt with Yellow Stripe

1 Dan (0kyu) Black Belt with White Stripe

1 Kyu to 5 Kyu Brown Belt

6 Kyu to 10 Kyu Red Belt

11 Kyu to 15 Kyu Blue Belt

16 Kyu to 20 Kyu Green Belt

25 Kyu to 21 Kyu Yellow Belt

30 Kyu to 26 Kyu White Belt

The "Problem", and Other Mere Kyu Thoughts

Many wonder about how strong pros are compared to amateurs. A few people get confused as to why a 6 Dan Amateur can Have a good record against a, say,3p. Then there is the debate about how these days there is barely any difference between 1p and 9p or 1p and top pros.

All these discussions can also be filled with errors.

I am glad to say that by doing research on igokisen.web.fc2.com, 361points.com, gooften.net, gogameguru.com and other sources, I have finally made a judgment day, un-changeable, un-deniable overview of Go Strength. I Wish. Unfortunately, what you are about to read is speculation from some random 7 kyu who doesn't have a single clue of what he is doing, so feel free to take it with a grain of salt.

edit: now 4 kyu

But remember, what ranks measure in its most basics sense is the expected percentage of correct decisions made for a given position compared to someone of a different rank-- a crude explanation, but trying to put something abstract into numbers can pose great challenges, circular dominance being an example, one reason it can seem like an uphill struggle. We have to simplify for now.

Please forgive the fact that people in Europe aren't as clued up about Insei in Korea, China or Taiwan, so most insei evidence comes from Japan.

Down to Business

Okay, let's face it. We have to temporarily completely disregard professional grades as an indicator of strength. Yes, you may say that "9p tend to be stronger than 1p, most of the time" or something like "But pro grades equal 1/4 of a stone", but look at it this way. Everyone knows p ranks are NOT for marking strength but one's EXPERIENCE times the AVERAGE STRENGTH he/she has had since becoming a pro

So that amounts to these grades being a haphazard way to show strength. It's just not what they're for. It's like using floor cleaner for washing up liquid. To stay on the safe side, it's best we avoid using them altogether.

But there is a small problem-- well, at least that's what I think. These days, professionals never play handicapped games against each other (I think), the only time you'll find that is if, for example, a dad is playing shidougo with his son like in Hikaru no Go. In the past, handicaps were a severe way of handling first move advantage, and in beat-down series, the loser can sometimes face damage to his reputation. It's no wonder pros today stay away from handicaps, because it's like condescending the opponent.

However, we can still us an extension of amateur Dan grading to the pro world, without the need for pro v pro handicapped games. We can also use the ones in the past that are already there, a good substitute (not a modern representation of pros).

What might help us is the fact that we know that the difference between a 20 kyu and 19 kyu is much, much smaller than that of a 5 Dan and 6 Dan. What is "difference"?


Let us state that one unit of skill is equal to that of a 30 kyu and 29 kyu for now, just to help us.

How many Units of Raw Skill, URS for short, does it take to get from 1 Dan to 2 Dan. I wonder. What may be good to know is that the amount of stones you give someone probably relies one your percentage of skill relative to the opponents skill.

So someone with 125% of the skill of a 20 kyu gives the same amount of stones as someone with 125% of the skill of a 1 Dan. We seem to have hit a rock with this theory, so we will pause for now.

Evidence, Part 1

At Go of Ten and 361 points ( [ext] http://361points.com/inseidetails/ ), we find vital information about the strength of Japanese insei.

"The D class insei were not so strong, maybe around European amateur 1-2 dan. C class insei were about the average-strength European amateur. B class insei were very strong for a European amateur."

Here, we can deduct that the bottom of D class is 1-2 Dan, and the top of B class around 7 Dan. Sorin Gherman Didn't talk about E class, and never made it to A class. But that was 10 Years ago. What about NOW!

"I donít know exactly how I should go about approximating the E class rankings, so Iíd start with the EGR ranking system assumption that with a winning percentage of 93% (very close to mine with 40 wins and 3 losses), there is a difference of about 3 ranks. Then, since there are clear differences between some of the inseiís levels, including a variation of one rank to both directions is probably reasonable. Me being EGF 6 dan, that would mean that the average E class insei would be about EGF 3 dan, and the insei of class E would be between EGF 2 dan and 4 dan in general. By intuition also after playing the games, I think this approximation should be close enough." Antti Tourmanen, 6 Dan at the time when he was first insei.

What we can take from this is that insei have become stronger over the course of 10 years, because the lower tier of D class is supposed to be at 4 Dan (compared to 1-2).

Of Course, the actual strength fluctuates every few months, so we will never get a more exact estimate because insei keep changing.

But after Mr Tourmanen spent more time as an insei with the Nihon Kiin and moved up to C class, we may get a more accurate estimate.

edit 05 jul 2014: And now after getting into A class

As someone who became an insei an experienced 6 dan, and soon after leaving promoted to 7 Dan, we may be able to create some kind of rough chart using the EGF standard (that would need to be refined by some kind SL users who pass by and know about insei).

A 7d-8d

B 6d-7d

C 5d-6d

D 4d-5d

E 2d-4d Extra temporary class

Update 12/08/2014, All numbers in EGF Dans. Of course, the level difference in each class seems to get tighter the higher up you go.

A 7.0-7.5

B 6.5-7.0

C 6.0-6.5

D 4.5-6.0

E 2.5-4.5 Extra Temporary Class

F 1.0-2.5 Rare Extra Class. This is a rough estimate for class F, even rougher than those already in the table.

We can see that the top few that actually become pros are equivalent to the crude estimation of 7.5 Amateur Dan.

Okay, So now we have some kind of idea of the strength of new pros, how do we find the strength of top pros?

Evidence, Part 2

[ext] http://www.361points.com/blog/2010/03/28/how-strong-are-professional-players/

"Pal Balogh 6d received 3 stones from Luo Xihe 9p and won by 3.5 points. This is the only instance when the amateur player won in the series of the Shusaku Cup demo/teaching games that I saw

Out of the 9 games shown, only 1 game was won. Even if we decide to ignore the two games where the handicap makes black equivalant to only 8Dan and not 9Dan as in all the others, with just one victory in a teaching game against top pros, we begin to get the feeling that top pro are actually closer to 10Dan than 9Dan-- the top pros must have had a slight edge in all the games, in all probability.

Remember the word "top" pros, not "newly qualified pros" It takes a HUGE amount of skill to become 2 stones stronger than 8Dan, and that is what TOP professionals are. They're truly something else. That is why you will find top pros consistently beat new pros in qualifying rounds of major tournaments, A large URS difference worth two stones in strength, and that huge skill is put into the most subtle differences between the quality of moves, giving only a slight advantage compared to the new pro in amateur terms, but in the pro world, it's decisive.

Pavol Lisy once opinionated that Europe is 3 stones behind Asia, and it seems that the (limited) evidence supports that statement.

Evidence, Part 3

[ext] http://www.wbaduk.com/FileUpDown/news/1c1(4).jpg [ext] http://www.wbaduk.com/FileUpDown/news/1c2(3).jpg [ext] http://www.wbaduk.com/FileUpDown/news/1c3(3).jpg

[ext] http://www.wbaduk.com/FileUpDown/news/2c1(2).jpg [ext] http://www.wbaduk.com/FileUpDown/news/2c2(2).jpg [ext] http://www.wbaduk.com/FileUpDown/news/2c3(2).jpg

courtesy of Wbaduk

You can see the full report here-- [ext] http://www.wbaduk.com/news/news_view.asp?menu_div=column&news_no=358 then [ext] http://www.wbaduk.com/news/news_view.asp?menu_div=column&news_no=361

Table 2

Updated 12/08/2014.

10 Dan _(-9kyu) World Class Top Professional, Grand Master

9.5 Dan (-8.5kyu) Top National Pro in Korea and likely in China, this seems to have been a wall for Japan's and Taiwans best pros.

9 Dan _ (-8kyu) Stronger Pro in Korea and maybe in China, in Japan and maybe in Taiwan it's "Top National pro level, and what I mean by that is that you're probably well-known among Go players in you're country, and can enter the main tournaments of or even challenge for title but not usually win open titles. It could also mean a former Top Pro.

8.5 Dan (-7.5kyu) "Average" in Korea and probably in China. Using the word average here becomes even worse. Stronger pro in Japan and maybe in Taiwan. The best amateurs in the world, many of whom failed to pass the insei test before reaching the age limit many years ago.

8 Dan _ (-7kyu) New Pro in Korea an maybe in china, "Average" in Japan and maybe in Taiwan, if a sane person could associate the word average with pro

7.5 Dan (-6.5kyu) New pro in Japan and probably in Taiwan, only a handful of non-Asians Have surpassed this level in the entire history of Go

7 Dan _ (-6kyu) Full Black Belt, Master, Top non-Asian player

6.5 Dan (-5.5kyu) 1p in the new European Pro system

6 Dan (-5kyu) Black Belt with Brown Stripe, Top Continental non-Asian player

5 Dan (-4kyu) Black Belt with Red Stripe

4 Dan (-3Kyu) Black Belt with Blue Stripe

3 Dan (-2kyu) Black Belt with Green Stripe

2 Dan (-1kyu) Black Belt with Yellow Stripe

1 Dan (0kyu) Black Belt with White Stripe, mastered the basics,

1 Kyu to 5 Kyu Brown Belt

6 Kyu to 10 Kyu Red Belt

11 Kyu to 15 Kyu Blue Belt

16 Kyu to 20 Kyu Green Belt

25 Kyu to 21 Kyu Yellow Belt

30 Kyu to 26 Kyu White Belt

The strongest pros fall somewhere in between the 9.5D and 10D zone, but for some reason almost all Japanese pros don't seem to be in the upper half of that scale.

"Not much harder than insei league..."

I'm sure no one has forgotten this--

"I remember that it was very hard to become a professional. I was almost 18 and it was my last chance to win the qualification among inseis. Of course, I did not think, that I can show good results quickly. I was surprised, that professional tournaments are not much harder than the insei league :)"

"Currently I am not stronger at all than other Korean junior players. Within 3 years I will try to win some tournaments for young professionals. I became a professional later than others, so I have to work harder and more seriously than them"

-Han Sanghoon

It seems to me that top Korean Yeungusaeng that become 1p are a bit stronger than A-Class Japanese insei who become 1p, but that still leaves some questions in believing that top professionals are two stones, or in korea one and a half stones stronger than newly qualified pros.

Okay, Okay...

There are many variables in a pro game, and each player has his/her own style with it's strengths and weaknesses-- in fact, so little is known about this Divine Game that when you get into pro ranks, a new pro can even rarely have an opinion which is better than a relatively strong pro. That is one reason why it's difficult to find the strength of pros. But one must simplify.

I know I am ignorant. And naive. There's no denying it. But maybe it's a start, I don't know, hopefully a strong player could help and correct me where I'm wrong, and that more people join the debate. There are many questions to answer, like what extra percentage of URS equals what amount of handi stones? One day we many know, and help solve this mystery for once.

*Sad Emotional and Sensational Ending Music to Make Everyone Sad Yet Still Strangely Excited about what the Future may Hold*

Me: I didn't ask for that.

Igo Ranks Explanation, Math and Estimation last edited by OneWeirdDude on December 6, 2017 - 00:06
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