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Google reveals secret test of AI bot to beat top Go players

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Re: Google reveals secret test of AI bot to beat top Go players

#171

Post by tel »

bluetwo wrote: post #21
dfan wrote: post #7

One thing that isn't made clear in this writeup is that Master plays in a very nonhuman style, as opposed to the version of AlphaGo that beat Lee Sedol, which mostly played like a strong human except for a few surprising moves. My first guess when I saw Master's games was that it was a program like AlphaGo that had its policy network trained from scratch rather than being bootstrapped by being given the goal of imita…

I don't know much about Go but I thought a comment about AlphaGo was interesting that it played in a way to marginally beat the player, which was different that most masters played, which is to clearly beat the opponent by as wide a margin as possible. Is this accurate? Does MasterP also use this style? Are there humans that can play this way? (I'm asking you because you seem to know what you are talking about here.)

All players play to marginally beat their opponent. Playing too aggressively when you're in the lead is "losing a won game" because it gives opportunities for your opponent to create turnarounds.

In the end of a well-played game the losing player will find that they perhaps get more points than they expect, but each time they win a tradeoff with a slight margin the position on the board becomes much more solid and fixed than it ought to be. A 10 point lead with a large variance consolidates toward an unfaltering 1/2 point lead.

Indeed, commentary on Master (P)s games seemed to suggest this was exactly how endgames went.

Early in the game, confidence in winning is usually correlated exactly with point margin... but at the same time, score in the early parts of the game is very hard to estimate. It's repeatedly noted that AlphaGo plays a very "influence oriented" game which means that it eschews confidently having many points for having lots of "power" on the board which will later translate to points.

So, all together I'd say that AlphaGo plays very well here and doesn't have too much of an obvious computational bias.

The one true oddity is once AlphaGo's internal win probability reaches 100% it starts playing idiotic moves. The reason is simple: it's just searching for moves which have the highest expected win rate and at this point nothing it can do is bad. It won't lose points or anything, but instead just plays moves that are obviously pointless.

Re: Google reveals secret test of AI bot to beat top Go players

#172

Post by tel »

halflings wrote: post #10
dfan wrote: post #7

One thing that isn't made clear in this writeup is that Master plays in a very nonhuman style, as opposed to the version of AlphaGo that beat Lee Sedol, which mostly played like a strong human except for a few surprising moves. My first guess when I saw Master's games was that it was a program like AlphaGo that had its policy network trained from scratch rather than being bootstrapped by being given the goal of imita…

Can you give some examples of what you consider non-human? Really curious since I don't know much about common strategies in Go.

AlphaGo often plays surprising moves. Typically high-level commentary describes the horizon of "surprising" here as playing wider, faster, and more influence-oriented than current professionals think is appropriate. AlphaGo is repeatedly praised for identifying moves which seem too unconcerned with the opponents threats and instead take more power on the board in a leisurely fashion. The first big surprising move it played was a "4th line shoulder hit" which was thought to give too much territory to the opponent (a "3rd line shoulder hit" is considered a very fine and popular move). AlphaGo showed that at the right time even the 4th line variant is good since is gave AlphaGo large influence at the right time and position.

A lot of go comes down to timing. AlphaGo doesn't seem to play moves which are inhuman in that they just make zero sense as much as plays moves which are more daring than humans would like to try. Then, infallibly, it turns out that AlphaGo's daring move had the mark of being amazingly well-timed.

Re: Google reveals secret test of AI bot to beat top Go players

#173

Post by daveguy »

21 wrote: post #120
nullnilvoid wrote: post #14

It seems that AlphaGo has got even better since when it defeated Lee Sedol. This time, AlphaGo is undefeated against other top players. However, it also gives other players a chance to practice against AlphaGo and finds weaknesses in AlphaGo, which is super important for any competition.

It would be super-weird if AlphaGo became worse that the previous version.

Neural networks have a bad habit of regressing. When training continues they tend to replace earlier skill with newer skill.

Re: Google reveals secret test of AI bot to beat top Go players

#174

Post by tel »

codehotter wrote: post #167
rdlecler1 wrote: post #84

I'd like to see if a small team of the worlds best go players could beat AG.

How much stronger is a team of top players than its strongest member? I wonder what the best way of coordination would be. Perhaps they can identify several promising lines and each player chooses one variation to calculate more deeply. From my own experience playing (as a weak amateur), I feel I'm rarely able to think so systematically -- often ideas I discover while contemplating one line are tried in entirely diff…

There's a very interesting book called The Go Consultants (http://www.slateandshell.com/SSJF003.html) which describes how professions have worked together during an extended time consultation game (2 v 2).

Re: Google reveals secret test of AI bot to beat top Go players

#175

Post by Diederich »

eutectic wrote: post #160
Diederich wrote: post #55

Earlier quoted context omitted.

> past the event horizon for human understanding I think this phrase is going to pop up more and more frequently.

This thread is literally the only Google search result for this phrase (for me)...

I searched for it in incognito mode and saw the same. Pretty interesting; it's such a nice, catchy phrase.

Re: Google reveals secret test of AI bot to beat top Go players

#176

Post by underyx »

koolba wrote: post #8

This seems like the beginnings of the plot of an anime I'd want to watch. Season two would probably start with the developer's getting complacent and a Chinese AI entering the scene.

No Game No Life[0] is somewhat related, it starts out with a mysterious and anonymous player beating everyone at online games.

[0]: https://en.wikipedia.org/wiki/No_Game_No_Life

Re: Google reveals secret test of AI bot to beat top Go players

#177

Post by hyperpape »

badminton1 wrote: post #101
hyperpape wrote: post #92

Earlier quoted context omitted.

Two things: 1) The two 9p professionals you mentioned achieved 9p status before the new promotion system you linked to. The new standards are much more stringent (though still based on lifetime achievement). 2) The standards differ by country. All the major countries now give out 9p ranks sparingly, but I think China especially may be quite difficult.

Sure but #1 is not so relevant since the old promotion system was also based in total number of wins rather than strength.

My understanding is that it was based on Oteai performance: there was an annual tournament and you had to score well enough against players of roughly your strength during a single year to improve. Winning half your games for 5 years in a row would not result in a promotion. Whereas today, you can grind out the requisite number of wins over the course of 2 years, 5 years or 10 years.

As such, the old system was, roughly speaking, based on your historical performance, not just wins.

But the bigger point is that it was very permissive. There were something like 70 9p professionals in Japan, and there will be quite fewer in the coming years (I believe Iyama Yuta is the only 9p aged less than 30).

Re: Google reveals secret test of AI bot to beat top Go players

#178

Post by inimino »

codehotter wrote: post #156
inimino wrote: post #148

Earlier quoted context omitted.

Professional go player Otake Hideo supposedly said he would ask for three stones if playing against God. That was before AlphaGo. My guess has always been that the real gap is much higher, and a perfect player could give 6 or even 9 stones to the world's top players. In perfect play there would be no such thing as joseki. I don't think it would be a game we would even recognize.

As play gets closer to optimal it gets more and more difficult to play more efficiently than your opponent. To play so much more efficiently than your opponent to overcome a handicap of 6 stones strikes me as extremely unlikely at pro level. At amateur level, say a 2d vs a 2k player would perhaps have a 99.9% winrate. To make it an even game, would take 4 handicap stones. But at pro level, I think it's possible for p…

In fact I agree, and if a perfect player were available, pro players would quickly get better at taking handicap!

What I really wanted to express is the amount of headroom available between top players and perfect play. When I say nine stones, I mean, whatever the win rate is between an idealized 9p and 8p player, there would be nine more such steps between the 9p player and god. Probably more. I don't necessarily mean that god would have even odds giving nine stones to top players, because that's a different game.

However, I have seen enough games where strong amateurs are taken apart with shockingly high handicaps by top pros, especially in faster games, to wonder. I think we simply fail to imagine how strange perfect play would be. Even if a pro spent the rest of their life thinking about the next move, they are unlikely to find the one true best move. A player that always played that move would be so far ahead of anything we've seen that we just can't imagine how much better it would be. Imagine knowing at move 10 that the best move, given perfect play by both, leads to a 3.5 point win in 256 more moves, while the second-best move leads to a 2.5 point win after 310 moves. Just stating it this way shows the amount of headroom there is above human play.

Re: Google reveals secret test of AI bot to beat top Go players

#179

Post by [deleted] »

codehotter wrote: post #156
inimino wrote: post #148

Earlier quoted context omitted.

Professional go player Otake Hideo supposedly said he would ask for three stones if playing against God. That was before AlphaGo. My guess has always been that the real gap is much higher, and a perfect player could give 6 or even 9 stones to the world's top players. In perfect play there would be no such thing as joseki. I don't think it would be a game we would even recognize.

As play gets closer to optimal it gets more and more difficult to play more efficiently than your opponent. To play so much more efficiently than your opponent to overcome a handicap of 6 stones strikes me as extremely unlikely at pro level. At amateur level, say a 2d vs a 2k player would perhaps have a 99.9% winrate. To make it an even game, would take 4 handicap stones. But at pro level, I think it's possible for p…

[deleted]

Re: Google reveals secret test of AI bot to beat top Go players

#180

Post by conanbatt »

aaron695 wrote: post #155
conanbatt wrote: post #127

Earlier quoted context omitted.

As a semi-pro player I can assure you thats not how you play Go.

You never study your up coming opponents previous games?

As a pro you study everyones games as a mean to get all the latest information possible, but there isn't really much you can do as a top pro to play against your opponents likings: the era were that could bear fruits ended decades ago.
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