Wednesday, March 9, 2016

Machines surpass humans in gaming world

This week is significiant as being the first time that a computer has beaten the world's best Go player.

The contest is a best of 5, with only the first game played, so it could all change, but at the time of writing AlphaGo, the machine that Google DeepMind have trained to play Go, is ahead.

Why is this significant?  In the 1990's chess IBM DeepBlue beat the world chess champion Gary Kasparov.  Two of the key ingredients of this success were brute force search algorithms, and a knowledge of chess strategy that was hard-wired into the computer program.

The number of possible Go games is much greater than the number of possible chess games because there is a much wider choice of moves in Go than in Chess.  When professional Go players are asked how they decide their next move, they say they rely havily on intuition, whereas a professional chess player will always know why they made a particular move, making it a lot easier to program a chess strategy to a computer.  So Alpha Go is impressive because it is playing a harder game, and one in which professional players depend on highly-developed sub-conscious decision making processes.

But what I find even more interesting is that the algorithms used to train AlphaGo are very general-purpose algorithms, that have been applied to a diverse range of Artificial Intellgence problems.  For example Google DeepMind used the same ideas / framework to train a computer to play Atari video games at the level of a professional video games tester.

Demis Hassabis said he was more impressed by Gary Kasparov than DeepBlue when Kasparov was beaten.  Gary Kasparov can do many other things apart from play chess - speak several languages, write books, tie his shoe-laces etc., whereas DeepBlue is a specialised intelligence for playing chess.  We are still a long way from machines being able to outperform humans in every domain, but I think it is fair to say that the last 20 years have seen a lot more progress in general-purpose machine intelligence than the last 200 years have seen progress in human intelligence.

Will machine intelligence reach some kind of saturation well below human levels?  Or will it catch up?  Or even surpass human intelligence?  The third option is starting to seem like an increasingly plausible idea to me.

For more, watch Demis Hassabis's recent lecture in Oxford,