This is not correct. In the professional ranks 1p is often no weaker than 9p because often the young players start out at 1p and are very strong because selection pressure is much greater. The 9p rank in Japan also came partly out of just playing a lot for a lot of years so that accomplishment was not as great as it seems. In any case, active professional players for the most part are not dramatically stronger than one another. The range for the most part is about 2 stones, maybe 3.

Even though Fan Hui is not an active professional in the traditional sense this is an absolutely huge accomplishment and leap in playing ability by computers. BTW, Michael Redmond is not particularly strong by professional standards.

(Edit: The correlation between strength and rank now as noted below is due to promotions more often coming from acheivements: If you win at X you get promoted to 7p immediately, if you win at Y you get promoted to 9p. You cannot win a big tournament and keep your low rank. Here is an example of someone who went from 3p to 9p in one match: https://en.wikipedia.org/wiki/Fan_Tingyu. But professionals cannot give each other 6 stone handicaps when one is 9p and the other is 3p)

This is not quite correct either. 1p is of course generally much stronger than an arbitrary amateur dan (even some (many? most?) 9d amateurs) and you can advance up the pro ranks quickly by winning certain games, but you can see the histograms yourself that while there's a clump of 9ps everywhere but China there's still a distribution. http://senseis.xmp.net/?ProfessionalRankHistograms Another problem is you don't lose your 9p rank once you earn it. It would be nice if there was an international Elo system tracking all the 9ps of various countries to rank them properly... Maybe someone's tried to calculate rankings independently? Still, I think it's pretty uncontroversial that someone who's been a lower-rank pro for longer than a few years is going to be significantly weaker than their higher-rank peers.

There are two major attempts at international ratings today. Dr. Bae Taeil does ratings for Korea, and Remi Coulom produces ratings independently, based on the database at go4go.net (http://goratings.org is the site).

Taeil's method seems unusual, though it may well be justified . I think he's using a relatively complete database of games, but I don't know for sure. Coulom has a very well regarded mathematical model, but we know that there are some gaps in the database, which a) may skew international comparisons, and b) may result in inaccurate ratings for players with few games in the database (but those players are usually not top players in the world).

See my comment below: there are very few 1p players near the top, unsurprisingly.

I feel like this is mostly misleading. Look at a list of top players (goratings.org). The top fifty is mostly players 5p and up. There are a few 3p or 4p Chinese players running around, and apparently even 1 1p (Li Qincheng) but by and large, there is a relation.

The beaten player is ranked 633 (Fan Hui).

Yes. He's a case where you'd make exactly the right assumption if just told his rank.

Though I should warn: as a low level pro who moved to Europe, this database has very little data on him. His European results indicate that he's stronger than Pavol Lisy, Alexander Dinerstein, and Mateusz Surma, who all rate higher than him here.

I don't think it's overblown at all. They make it clear he is the European champion and never imply he is the best player in Go, just obviously very good. Looks like he has won the last 3 European championships in a row (https://en.wikipedia.org/wiki/European_Go_Championship).

Overall I think it was a well balanced article highlighting an impressive achievement, not sure why you felt the need to diminish it as not significant?

The version of AlphaGo used in the paper beats CrazyStone about 99% of the time. Even if we give CrazyStone 4 stones handicap, AlphaGo still beats it 80% of the time.

Very nice. How come you guys didn't enter the UEC Cup? (Edit: rereading this it kind of sounds snarky, not meant that way. Really impressive if you can kick CrazyStone's teeth in...)

Is that with 1200CPU's?

From the paper, no that's with "single machine AlphaGo" which is 48 CPUs and 8 GPUs. Distributed AlphaGo beats Single Machine AlphaGo 77% of the time. (Distributed AlphaGo being 1202 CPUs and 176 GPUs.)

It beats single machine alpha go 77% of the time with four stones handicap. Right?

Looks like the other way round - single machine alphago wins 77% of the time, when it gives 4 stones handicap.

It's worth clarifying your use of the "p" rating scale alongside the "dan" rating scale. Essentially, there's an "amateur dan" scale which is what's measured on public servers like KGS. Under this scale essentially all professional Go players rank at the maximum rank, 9 dan.

In parallel there's the professional ranking system which also uses the title "dan" but is bestowed by the professional Go associations of every country. These rankings are symbolic instead of quantified, although generally higher professional dan ranks cannot be anything but corresponding to higher skill.

So, a "European 2d" is a professional rank which may or may not have a good translation into a quantitative scale like ELO or "KGS dan" (I actually don't know). Generally, my understanding is that European professional rankings lag behind Asian ones as well by some amount.

You're generally accurate, except that Fan Hui is a Chinese 2p from the Chinese Pro Association who has played in Europe for several years. He's still generally a bit stronger than the homegrown European professionals.

Ah, gotcha! Didn't realize his rank was from the Chinese association.

Do you realize that AlphaGo has a 77% win rate against CrazyStone with a four stone handicap? It is far far stronger than CrazyStone and Zen.

Pro ranks are much closer than amature ranks. The difference between a 9p and 6p is probably less than one stone, and definitely less than three.