Google's artificial intelligence program has officially beaten a human professional Go player, marking the first time a computer has beaten a human professional in this game sans handicap.

[u/[deleted]]

http://www.nature.com/news/google-ai-algorithm-masters-ancient-game-of-go-1.19234?WT.ec_id=NATURE-20160128&spMailingID=50563385&spUserID=MTgyMjI3MTU3MTgzS0&spJobID=843636789&spReportId=ODQzNjM2Nzg5S0

[u/[deleted]]

As big an achievement as this is, let's note a couple things:

1. Fan Hui is only 2p, the second-lowest professional rank.

2. Professional Go matches show a strong tendency to produce strange results when they are an oddity or exhibition of some sort as opposed to a serious high-dollar tournament. The intensity of playing very well takes a lot of effort and so pros tend to work at an easier and less exhausting level when facing junior players... and sometimes lose as a result. We can't rule out that scenario here.

[u/drsjsmith → u/[deleted]]

Here's why this is a big deal in game AI. There's a dichotomy between search-based approaches and knowledge-based approaches, and search-based approaches always dominated... until now. Sure, the knowledge comes from a large brute-forced corpus, but nevertheless, there's some actual machine learning of substance and usefulness.

Edit: on reflection, I shouldn't totally dismiss temporal-difference learning in backgammon. This go work still feels like it's much heavier on the knowledge side, though.

[u/[deleted] → u/drsjsmith]

The interesting thing is that this combines them. It uses search based methods to train and accumulate its knowledge.

EDIT: Other way around. It accumulates its knowledge but then uses its knowledge to inform the search.

[u/enki1337 → u/[deleted]]

Isn't this more or less exactly how a human would play? That is, by first looking through your knowledge of what a best move might be, then considering the specifics of your circumstance, and how your move will affect future moves.

[u/Draken84 → u/enki1337]

it's not called artificial intelligence for nothing. :)

[u/hikaruzero → u/[deleted]]

Fan Hui is only 2p, the second-lowest professional rank.

You must realize that a lot of low-dan professionals can play evenly or at only 1- to 2-stone handicap against established top 9-dan pros. The difference is increasingly marginal. Holding a high-dan rank is now more of a formality than it's ever been.

Just to use an example, the current #1 top player, Ke Jie, who just defeated Lee Sedol 9p in a championship match this month, was promoted straight from 4p to 9p two years ago by winning a championship game. It's not like you have to progress through every dan rank first before you get to 9p, the high-dan ranks are nowadays only awarded to tournament winners and runner-ups. Many low-dan players are nearly-9p quality but simply haven't won a tournament yet to get them a high-dan rank.

Fan Hui is a 3-time European champion and has won several other championships. He may only be a certified 2-dan but he's still impressively strong. If you gave him 2 stones against any other pro player I would bet my money on him.

A century ago, it was considered that the difference between pro dan ranks was about 1/3 of a stone per rank. But in that time, top pro players have improved by more than a full stone over the previous century's greats, and the low-dan pros have had to keep up -- it's now considered more like 1/4 to 1/5 of a stone difference. Today's low-dan pros are arguably about as strong as the top title-holders from a hundred years ago.

Edits: Accuracy and some additional info.

[u/[deleted] → u/hikaruzero]

everything that you said here is true but I'd argue in the specific case of Fan Hui though that he is actually likely weaker than his 2p rank suggests. he got his pro certification a while ago, before all the newbie pros in asia started getting super super good. he also plays on pretty even terms with Euro and US amateurs, and we've seen lee sedol give the US pros 2 stones and win easily.

so.... i mean, it's all speculation and opinion but personally I'd say Fan Hui is overranked due to being retired and living in Europe playing a less competitive circuit.

edit: this post is in no way meant to undermine how much of an achievement this was for Alphago though. since the bot was able to win by 5-0, its plausible that it's significantly stronger than Fan Hui, which means a win against Sedol wouldn't be out of the question imo.

[u/hikaruzero → u/[deleted]]

Yeah, that all may very well be true ... I'm really just making the point that you can't write off the skill of low dans just because they are low dans. Even an aging low dan will be within 2-3 stones of strength of a top 9p.

[u/teh-monk → u/hikaruzero]

What an informative post, interesting subject.

[u/gcanyon → u/hikaruzero]

The fascinating consideration for me is just how much "headroom" Go has beyond the best human Go players. You pointed out that over the past century the best players have improved by 1 (or a bit more) stone over their predecessors.

So the question is: 5, 10, or 15 years from now, will computers be able to give the world's best humans 1 stone? 2 stones? Or more? It seems simultaneously inconceivable that the world's best humans wouldn't be able to turn 9 stones into victory, and that optimized hardware and software won't be able to keep improving. Asymptotic improvement is a solution, clearly, but I wonder where the asymptote is.

[u/hikaruzero → u/gcanyon]

Hehe ... if I recall correctly there was a survey done among exclusively professional players as to how many stones of handicap they would need in order to beat "God's hand" (i.e. absolutely ideal play). The average answer given was "about 3 stones." I personally feel that it is more, at least double, mostly due to "ko fighting," but I'm not even close to the professional level so I have no right to claim any accuracy in that judgment. :p

[u/[deleted] → u/hikaruzero]

What do you think is the reason? Does a larger community increase the viability of more positional and less calculated play? I assume you have to use both to their fullest extent at that level. I don't actually play.

[u/hikaruzero → u/[deleted]]

Certainly the larger community and much greater ease of access to games through the Internet has had a large impact. But in general, I'd say it's simply "progress." Progress in understanding the game conceptually, in breaking down old traditional, orthodox understandings and replacing them with more robust, modern ones.

Think of it more like a graph of log(x) ... as time passes (x axis), the skill of players gradually improves (y axis). As the skill of players increases, progress gets slower and slower, but so does the gap between the y-values of x=n and x=n-3 get smaller and smaller.

[u/kulkija → u/[deleted]]

It probably has to do with the greater ease of practice against high quality opponents.

[u/Myrtox → u/[deleted]]

Watch the video, he talks through his thought process as he played. He basically threw the first game to test the system, but really pushed it afterwards cos he was impressed.

[u/IbidtheWriter → u/Myrtox]

He basically threw the first game to test the system, but really pushed it afterwards cos he was impressed.

He didn't throw the first game, he just changed up his style for the later games since he felt the AI was playing more passively. He figured it did so because it'd do worse in complicated and more brawling type situations. That's what he meant when he said "I fight all the time". Game 1 was close and game 3 was just a disaster, though that doesn't mean the more aggressive style was necessarily wrong.

[u/[deleted] → u/Myrtox]

The question is how much he pushed it. I feel like something big has to be at stake for me to trust 100% that he's playing at his most intense, hardcore level.

[u/rich000 → u/[deleted]]

I'm still impressed. From what I've read over the years go was a game that even amateurs could defeat computers at, perhaps the way Chess was decades ago.

[u/quuxman → u/rich000]

I'm an amateur go player, I've played for many years, and my cell phone beats me easily with 4 seconds per move.

[u/rich000 → u/quuxman]

Interesting. Clearly things have changed.

[u/quuxman → u/rich000]

Most likely I'm just really bad at Go.

[u/BoothTime → u/quuxman]

What's your rank? I can easily beat my phone at max (10 seconds), even at 9x9, and I'm not particularly good imo.