The Infinity Machine by Sebastian Mallaby review – the story of the man who changed the world

I t was March 2016, and at the Four Seasons Hotel in Seoul, the world was gathered to watch the culmination of a battle 2,500 years in the making. On one side was the South Korean Lee Se-dol, the second-highest ranking Go player in the world. On the other was AlphaGo - a computer program developed by London-based artificial intelligence research company DeepMind. "Chess is the greatest game mankind has invented," game designer Alex Randolph once said. "Go is the greatest game mankind has discovered."