[Computer-go] Facebook Go AI

[Rémi Coulom]

It is darkforest, indeed:

Title: Better Computer Go Player with Neural Network and Long-term 
Prediction

Authors: Yuandong Tian, Yan Zhu

Abstract:
Competing with top human players in the ancient game of Go has been a 
long-term goal of artificial intelligence. Go's high branching factor 
makes traditional search techniques ineffective, even on leading-edge 
hardware, and Go's evaluation function could change drastically with one 
stone change. Recent works [Maddison et al. (2015); Clark & Storkey 
(2015)] show that search is not strictly necessary for machine Go 
players. A pure pattern-matching approach, based on a Deep Convolutional 
Neural Network (DCNN) that predicts the next move, can perform as well 
as Monte Carlo Tree Search (MCTS)-based open source Go engines such as 
Pachi [Baudis & Gailly (2012)] if its search budget is limited. We 
extend this idea in our bot named darkforest, which relies on a DCNN 
designed for long-term predictions. Darkforest substantially improves 
the win rate for pattern-matching approaches against MCTS-based 
approaches, even with looser search budgets. Against human players, 
darkforest achieves a stable 1d-2d level on KGS Go Server, estimated 
from free games against human players. This substantially improves the 
estimated rankings reported in Clark & Storkey (2015), where DCNN-based 
bots are estimated at 4k-5k level based on performance against other 
machine players. Adding MCTS to darkforest creates a much stronger 
player: with only 1000 rollouts, darkforest+MCTS beats pure darkforest 
90% of the time; with 5000 rollouts, our best model plus MCTS beats 
Pachi with 10,000 rollouts 95.5% of the time.

http://arxiv.org/abs/1511.06410

Rémi

On 11/03/2015 08:32 PM, Nick Wedd wrote:
> I think this Facebook AI may be the program playing on KGS as 
> darkforest and darkfores1.
>
> Nick
>
> On 3 November 2015 at 14:28, Petr Baudis <pasky at ucw.cz 
> <mailto:pasky at ucw.cz>> wrote:
>
>       Hi!
>
>       Facebook is working on a Go AI too, now:
>
>     https://www.facebook.com/Engineering/videos/10153621562717200/
>     https://code.facebook.com/posts/1478523512478471
>     http://www.wired.com/2015/11/facebook-is-aiming-its-ai-at-go-the-game-no-computer-can-crack/
>
>     The way it's presented triggers my hype alerts, but nevertheless:
>     does anyone know any details about this?  Most interestingly, how
>     strong is it?
>
>     --
>                                     Petr Baudis
>             If you have good ideas, good data and fast computers,
>             you can do almost anything. -- Geoffrey Hinton
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>
>
>
> -- 
> Nick Wedd maproom at gmail.com <mailto:maproom at gmail.com>
>
>
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