How did Google's AlphaZero beat the world's best chess computer?

Google’s AlphaZero, after just four hours of training, last week trounced the highest rated chess engine in the world, Stockfish. How did it do this? 

CB article on AlphaZero suggests AlphaZero is playing a different

DeepMind's AlphaZero crushes chess

AlphaZero: Shedding new light on chess, shogi, and Go - Google

AlphaZero: Checkmate - History of Data Science

AlphaZero - Wikipedia

Dispatches from the frontiers of chess

Google says it built a 'superhuman' game-playing AI. Is it truly

Google's AlphaZero Destroys Stockfish In 100-Game Match

AI Ruined Chess. Now, It's Making the Game Beautiful Again

The Chess Player That Mocked Her Opponent

DeepMind's AlphaZero AI is the new champion in chess, shogi, and Go

Google's AlphaZero surpassed the sum of human chess knowledge

DeepMind's AlphaZero crushes chess

Google AI teaches itself 'superhuman' chess skills in four hours