AlphaGo beats Lee Sedol again in match 2 of 5 • Hacker News Board

Re: AlphaGo beats Lee Sedol again in match 2 of 5

#411

Post by mtgx » Thu, Mar 10, 2016, 4:47 PM UTC

fhe wrote: post #239

As someone who studied AI in college and am a reasonably good amateur player, I have been following the matches between Lee and AlphaGo. AlphaGo plays some unusual moves that go clearly against any classically trained Go players. Moves that simply don't quite fit into the current theories of Go playing, and the world's top players are struggling to explain what's the purpose/strategy behind them. I've been giving it…

I believe that when Google talked last year about DeepMind playing those 70's Atari games, it also surprised the team with some of the tricks that it learned to be more effective in the game. So this is quite interesting stuff.

Re: AlphaGo beats Lee Sedol again in match 2 of 5

#412

Post by nandemo » Thu, Mar 10, 2016, 4:48 PM UTC

brianchu wrote: post #177

nandemo wrote: post #163

Earlier quoted context omitted.

I don't think so. Pros are already pretty good at the endgame. Yeah, they make blunders now and then, so it's possible that AlphaGo would gain a few points in the endgame in some games, but not enough to overcome a significant lead and not every time. In any case, I personally find it more interesting to see what we can learn from AlphaGo about the opening and the midgame.

Isn't that what I'm saying though? If you're tied/close going into the endgame, AlphaGo will probably win.

My writing was sloppy, let me rephrase it: in a pro match, whatever is the estimated score when the game goes into the endgame, that will likely be the final score.

Where I wrote that a pro will blunder "now and then" I should have written "rarely" -- I don't have data to back this up but I'd guess once in every n games for some n > 30.

Re: AlphaGo beats Lee Sedol again in match 2 of 5

#413

Post by lmm » Thu, Mar 10, 2016, 4:49 PM UTC

hutzlibu wrote: post #384

reacweb wrote: post #305

Earlier quoted context omitted.

In go, the purpose is to have more territory than the opponent. There is no point in humiliating the opponent by having a big advantage. I think the aim of the strange moves was to increase the confidence of the program in its advance, not to increase the advance.

But you could indeed humiliate the opponent by actually capturing ALL of his stones. But that won't happen, if the enemy knows at least the basic concepts ... Still, if you play well, you cover much ground - while trying to supress the area of the enemy and even crushing him. But classic go is nice in a way, that it gives weaker opponents a start bonus of some stones - so the game is balanced and domination usually w…

My brother once played the (then) British Youth Go Champion on a 13x13 board, and lost by around 180 points - literally scoring worse than if he hadn't played at all.

Re: AlphaGo beats Lee Sedol again in match 2 of 5

#414

Post by acheron » Thu, Mar 10, 2016, 4:50 PM UTC

Cookingboy wrote: post #116

Someone somewhere asked why a lot of people in the Go community is taking this in a somewhat hard way, here is my hypothesis: Go, unlike Chess, has deep mytho attached to it. Throughout the history of many Asian countries it's seen as the ultimate abstract strategy game that deeply relies on players' intuition, personality, worldview. The best players are not described as "smart", they are described as "wise". I thin…

> Now imagine the winning author of the next Hugo Award turns out to be an AI, how unsettling would that be.

Considering some of the recent Hugo winners, it turns out the story doesn't actually have to be good, so yeah, a computer-written story winning is probably closer than we think.

Re: AlphaGo beats Lee Sedol again in match 2 of 5

#415

Post by cjbprime » Thu, Mar 10, 2016, 4:50 PM UTC

rurban wrote: post #172

What I really liked about those games so far, and Michael Redmond commentary, is that AlphaGo not only beat Lee Sedol twice, but also Redmond. He is playing the same style as Sedol, he constantly predicts Sedol's moves and he is as surprised and does the same miscalculations as Sedol. He really needs some time to find out when he made a mistake, the same mistake Sedol was eventually doing. This is high class commenta…

> He remembers all the stones and immediately clears his own moves, amazing.

Chess grandmasters can often play simultaneously and blindfolded against 20 different opponents (and win all but one or two games). This is nowhere near the extent of Redmond's memory strength. :)

Re: AlphaGo beats Lee Sedol again in match 2 of 5

#416

Post by iopq » Thu, Mar 10, 2016, 4:50 PM UTC

pavelrub wrote: post #250

liviu- wrote: post #195

Earlier quoted context omitted.

>It was noted that even in 9x9 Go, with a comparable branching factor to Chess, traditional Go programs are still no stronger than on big boards. Are they not? MoGo beat pros of 9 Dan on 9x9 in 2011: https://www.lri.fr/~teytaud/mogo.html

Well, I guess it was more true before the advent of Monte Carlo Tree Search. Even so, note that even in the case of MoGoTW in 2011, it played blind Go (this helps the computer), and out of 4 games, won two games against a 9p player, and lost 1 game to a 5p player. Though it is perhaps better than MoGo's performance on 19x19, it still isn't very good, doesn't seem much better than MoGo on 13x13, and performs much wors…

The branching factor is much larger, around 75 legal moves after the opening, while chess has at most like 30.

Fuego beat a pro in 2008 using MCTS actually.

Re: AlphaGo beats Lee Sedol again in match 2 of 5

#417

Post by astrofinch » Thu, Mar 10, 2016, 4:51 PM UTC

CyberDildonics wrote: post #390

astrofinch wrote: post #257

Earlier quoted context omitted.

There's also the fact that some of the unexpected moves were apparently more about solidifying against a loss than increasing the magnitude of a win. Which has its own kind of eerie implication: since AIs (like all computer programs) do what you say, not what you mean, the "intelligent species" can sometimes work really intelligently towards a goal that wasn't quite what you had in mind. (Gets especially interesting…

> the "intelligent species" can sometimes work really intelligently towards a goal that wasn't quite what you had in mind. That's called programming

Right. Skynet and Terminator are science fiction, but the slippery, unpredictable reality of how computers actually behave is right in front of your eyes as a programmer every day. Sometimes I wonder if science fiction writers do more harm than good: once they make a movie about some possible future, people feel free to dismiss it as "just science fiction", even if they have easily available empirical evidence that something vaguely like the scenarios described actually kinda has the potential to occur.

Re: AlphaGo beats Lee Sedol again in match 2 of 5

#418

Post by bduerst » Thu, Mar 10, 2016, 4:51 PM UTC

lpage wrote: post #406

forgotpwtomain wrote: post #303

Earlier quoted context omitted.

> It's both exciting and eerie. It's like another intelligent species opening up a new way of looking at the world (at least for this very specific domain). and much to our surprise, it's a new way that's more powerful than ours. I have been watching Myungwan Kim's commentary for the games - and it seems notable that a few moves he finds very peculiar immediately when they are made, he will later point out to as achi…

> he will later point out to as achieving very good results some 20 moves later This. It's a fairly common feature of any AI that uses some form of tree search/minimax, and the effect is very pronounced in chess. Even the best human players can only think 6-8 plies into the feature versus ~18 for a computer. What we can (could?) do is apply smarter evaluation functions to the board states resulting from candidate pla…

Wasn't the breakthrough with AlphaGo that it doesn't consider every board combination in the future? Because that there are too many combinations?

Re: AlphaGo beats Lee Sedol again in match 2 of 5

#419

Post by EGreg » Thu, Mar 10, 2016, 4:54 PM UTC

btilly wrote: post #408

Ensorceled wrote: post #322

Earlier quoted context omitted.

> AlphaGo plays some unusual moves that go clearly against any classically trained Go players. Moves that simply don't quite fit into the current theories of Go playing, and the world's top players are struggling to explain what's the purpose/strategy behind them. Could AlphaGO be winning in a way similar to left handed fencers having an advantage over right handers by wrong footing them rather than simply being bett…

Absolutely! And it doesn't matter in the end... Remember that AlphaGo has spent months developing its own style and theory of the game in a way that no human has ever seen. Its style is sure to have weaknesses, but humans will have a hard time figuring them out on first sight. Similarly chess computers do better in some positions than others (they love open tactics!) and one of the games that Kasparov won against Dee…

But when the weaknesses it has require looking 20 ply into the game, can anyone exploit those weaknesses? And furthermore, if the computer itself is able to see 20 ply into the game, then it can spot its own weaknesses and you need to look even further, making the question of whether it's really a weakness.

Weaknesses are only relative to capabilities of the opponent to exploit them. If a tank has a weak spot that rockets can hit, but it's being opposed by humans on horseback, is it really a weakness in that context?

Re: AlphaGo beats Lee Sedol again in match 2 of 5

#420

Post by kqr » Thu, Mar 10, 2016, 4:55 PM UTC

oneeyedpigeon wrote: post #197

derefr wrote: post #82

Earlier quoted context omitted.

> all the players will simultaneously consider the same branches A computer-assisted pool of humans might work. Feed each human a board state advanced by 1/2/3/N moves down the decision tree in some direction, and have them evaluate that particular sub-tree. It's a map-reduce problem!

> have them evaluate that particular sub-tree Is there a meaningful response that each one could give that would be optimal? I figure this would only stand a chance of working if the pool of humans were cloned from a 9 dan :-)

Each one needn't give a 9 dan response. Each person gives one response to the best of their ability, and scores the situation on a scale of like 1–100. Collect all the responses and distribute the new board situations over the same – or a different – group of people. The score is mostly used to value the quality of previous moves. If a branch leads from a situation most people rated as 60 to a situation where most people rate 10 it's not a good branch.