V_V comments on AlphaGo versus Lee Sedol - Less Wrong

17 Post author: gjm 09 March 2016 12:22PM

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Comment author: V_V 09 March 2016 04:29:21PM 7 points [-]

What I'm curious about is how much this reflects an attempt by AlphaGo to conserve computational resources.

If I understand correctly, at least according to the Nature paper, it doesn't explicitly optimize for this. Game-playing software is often perceived as playing "conservatively", this is a general property of minimax search, and in the limit the Nash equilibrium consists of maximally conservative strategies.

but I was still surprised by the amount of thought that went into some of the moves.

Maybe these obvious moves weren't so obvious at that level.

Comment author: Error 09 March 2016 06:16:03PM 3 points [-]

I don't know about that level, but I can think of at least one circumstance where I think far longer than would be expected over a forced move. If I've worked out the forced sequence in my head and determined that the opponent doesn't gain anything by it, but they play it anyway, I start thinking "Danger, Danger, they've seen something I haven't and I'd better re-evaluate."

Most of the time it's nothing and they just decided to play out the position earlier than I would have. But every so often I discover a flaw in the "forced" defense and have to start scrabbling for an alternative.

Comment author: WalterL 09 March 2016 06:34:51PM 4 points [-]

This is very true in Go. If you are both playing down a sequence of moves without hesitation, anticipating a payoff, one of you is wrong (kind of. It's hard to put in words.) It is always worth making double sure that it isn't you.

Comment author: Vaniver 09 March 2016 07:20:34PM 2 points [-]

Maybe these obvious moves weren't so obvious at that level.

Sure. And I'm pretty low as amateurs go--what I found surprising was that there were ~6 moves where I thought "obviously play X," and 이 immediately played X in half of them and spent 2 minutes to play X in the other half of them. It wasn't clear to me if 이 was precomputing something he would need later, or was worried about something I wasn't, or so on.

Most of the time I was thinking something like "well, I would play Y, but I'm pretty unconfident that's the right move" and then 이 or AlphaGo play something that are retrospectively superior to Y, or I was thinking something like "I have only the vaguest sense of what to do in this situation." So I guess I'm pretty well-calibrated, even if my skill isn't that great.