Harry Pot for Anefo ]] · CC BY-SA 3.0 nl

Won the world chess championship five times across three separate reigns, becoming the first world-class player developed entirely within the Soviet Union while working the whole time as an electrical engineer. He helped design the modern format for the World Chess Championship and built the Soviet coaching system that trained his eventual successors, including Anatoly Karpov, Garry Kasparov, and Vladimir Kramnik. Later in life he pursued computer chess and was awarded an honorary mathematics degree for the work.