South Korean Lee Sedol, the world Go champion in the past 10 years, on Thursday expected a"not easy" game with Google's computer program AlphaGo in the third of a historic five-game match scheduled for Saturday.
"It seems not easy,"Lee told a press conference after being defeated twice by the artificial intelligence (AI). But he didn't give up hope for his first victory, saying his winning possibility would rise more or less if he plays in his favor before the middle of the game in consideration of past matches.
Lee, one of the greatest Go players who have won 18 world championships for 21 years of his professional career, was beaten for the second time by AlphaGo, a computer program developed by Google's London-based Ai subsidiary DeepMind.
The human Go champion had been confident of his 5-0 victory over AlphaGo during the Feb. 22 press conference, but showed less confidence after listening to the DeepMind's presentations about the computer program a day before the opening match.
After the first defeat, Lee predicted a 50-50 victory and then, further downgraded his winning possibility after the second loss.
AlphaGo boasts of a deep learning capability that enables the AI to discover new strategies by playing games against itself and adjusting neural networks based on a trial-and-error process known as reinforcement learning.
During the Thursday match, AlphaGo showed anomalies and moves from a broader perspective which professional Go players described as looking like mistakes at the first sight but an intentional strategy in hindsight.
Lee said he was sufficiently surprised at the Wednesday match with AlphaGo and the Thursday match made him have nothing to say any longer.
The 33-year-old acknowledged his complete defeat, saying that he had never felt his favor for even a moment throughout the match.
He said he may have lost the games twice because he didn't find any weak points from AlphaGo, adding that AlphaGo made a completely play at the second match.
The"match of the century"between a human and AI, which kicked off on Wednesday, will last until next Tuesday. The next match will be held on Saturday in Seoul.