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AlphaGo Zero: Learning from scratch

deepmind.com

31–40 of 324 posts

Re: AlphaGo Zero: Learning from scratch

#31
So this is fun:

"AlphaGo Zero is the program described in this paper. It learns from self-play reinforcement learning, starting from random initial weights, without using rollouts, with no human supervision, and using only the raw board history as input features. It uses just a single machine in the Google Cloud with 4 TPUs (AlphaGo Zero could also be distributed but we chose to use the simplest possible search algorithm)."

Re: AlphaGo Zero: Learning from scratch

#32
post #22
post #18

Earlier quoted context omitted.

The core technique of AlphaGo is using tree search as a "policy improvement operator". Tree search doesn't work on most real-world tasks: the "game state" is too complex, there are too many choices, it's hard to predict the full effect of any choice you might make, and there often isn't even a "win" or "lose" state which would let you stop your self-play.

This version explicitly does not use tree search.

The new version does use MCTS, you should read the paper again. :)

Re: AlphaGo Zero: Learning from scratch

#33
post #4

"It uses one neural network rather than two." and "AlphaGo Zero only uses the black and white stones from the Go board as its input, whereas previous versions of AlphaGo included a small number of hand-engineered features." This is amazing! The technology they came up with must be super generic.

I will be interested to see what kind of algorithms they have used to allow AlphaGo to learn from its own moves. Are these pretty generics algos or are these very customized and specific ones that only apply to AlphaGo and the game of Go?

Re: AlphaGo Zero: Learning from scratch

#35

> Previous versions of AlphaGo initially trained on thousands of human amateur and professional games to learn how to play Go. AlphaGo Zero skips this step and learns to play simply by playing games against itself, starting from completely random play. So technically this version has lost every game it's ever won. Jokes aside, it's pretty interesting to note that they were able to combine the "policy" and "value" net…

https://blog.openai.com/ I believe their DotA 2 AI uses that approach

Thanks!

Re: AlphaGo Zero: Learning from scratch

#37
post #30

Is this evidence of a broader leap forward in machine learning, or are these advancements domain-specific? In other words, could these innovations be applied to other fields and applications?

I think the fact that it's no longer using Monte Carlo tree search is a huge step forward in the generalizability of the technique. But go is still - a perfect information game - with a relatively small input size (vs. arbitrary computer vision) - cheap to simulate - discrete action space - deterministic This isn't to take away from the magnitude of the achievement, but the nature of the problem itself makes the resu…

Math research shares those qualities, except small input size if you include the body of all the already-known theorems as an input. I don't know if we'll see much smarter proof assistants soon, but it doesn't seem absurd to me as a possible development.

Re: AlphaGo Zero: Learning from scratch

#38
post #22
post #18

Earlier quoted context omitted.

The core technique of AlphaGo is using tree search as a "policy improvement operator". Tree search doesn't work on most real-world tasks: the "game state" is too complex, there are too many choices, it's hard to predict the full effect of any choice you might make, and there often isn't even a "win" or "lose" state which would let you stop your self-play.

This version explicitly does not use tree search.

It does, during training.

Re: AlphaGo Zero: Learning from scratch

#39
post #7

I'm reminded of Eliezer Yudkowski's article "There is no fire Alarm for Artificial General Intelligence." Is this smoke? https://intelligence.org/2017/10/13/fire-alarm/ Yes, this is not an AGI. But the hockey-stick takeoff from defeats some players, to defeats an undefeated world-champion, to defeats the version of itself that beat the world champion 100% of the time is nuts . If this happens in other domains, like f…

Wait for Alpha StarCraft for some real panic. So far RL based method has limited success outside of simple games(Not to say Go is simple, but rather the presentation and control parts of the format).

Re: AlphaGo Zero: Learning from scratch

#40
post #22

Earlier quoted context omitted.

This version explicitly does not use tree search.

It does, during training.

Tree search is also used during play. In the paper, they pit the pure neural net against other versions of the algorithm -- it ends up slightly worse than the version that played Fan Hui, at about 3000 ELO.
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