Why AlphaGo Zero is a Quantum Leap Forward in Deep Learning

The 1983 movie "War Games" has a memorable climax where the supercomputer known as WOPR (War Operation Plan Response) is asked to train on itself to discover the concept of an un-winnable game. The character played by Mathew Broderick asks "Is there any way that it can play itself?" The solution is the same, set the number of players to zero (i.e. There is plenty to digest about this latest breakthrough in Deep Learning technology. DeepMind authors use the term "self-play reinforcement learning". As I remarked in the piece about "Tribes of AI", DeepMind is particularly fond of their Reinforcement Learning (RL) approach.