In what marks a significant advance for the field of AI, AlphaGo has today claimed victory in a five-game series, but not before South Korean Lee Sedol could land a few shots of his own. 

The Google DeepMind Challenge kicked off last week in Seoul, pitting Sedol against the purpose-built AlphaGo computer program in a best of five series. Google-acquired artificial intelligence firm DeepMind had set out to build the best Go player in the world, but doing so would require some novel approaches to machine learning. In fact, in 2014 experts estimated that it could be a decade before AI advanced enough to allow a computer to win at Go without a handicap. 

The team built an advanced search tree to sort through all the possible positions on the Go board, which equate to more atoms than are in the universe, along with deep neural networks. These networks process a description of the board through millions of neuron-like connections, with a so-called "policy network" picking the next move to play, while a "value network" predicts who will go on to win the game.