 Zen 2 was released on 27 August 2010, Zen 3 on 30 September 2011, Zen 4 on 27 July 2012, and Zen 5 on 13 December 2013.After the AlphaGo AI defeated professional players Fan Hui 2p and Lee Sedol 9p in 2015 and 2016, Yoji was inspired to upgrade Zen with deep learning algorithms.In November 2016, “DeepZenGo” played and lost a three-game match against Cho Chikun 9p; the AI won one game and lost the other two.