Lee Se-dol

Lee Sedol, or Lee Se-dol, is a South Korean former professional Go player of 9 dan rank. As of February 2016, he ranked second in international titles (18), behind only Lee Chang-ho (21). His nickname is "The Strong Stone" ("Ssen-dol"). In March 2016, he played a series of matches against the program AlphaGo that ended in Lee losing 1–4.