Cho Chikun
In November 2016, 8 months after Lee Sedol was defeated by computer program AlphaGo, Cho Chikun played a 3-game challenge match against program Zen. Cho won a close game 1, lost game 2 when his invasion into enemy territory was killed, and won game 3. Zen uses neural network techniques similar to AlphaGo, however ran on more modest hardware during the match.