American Go E-Journal

Lee Sedol 9P made a comeback Sunday after three consecutive losses, to beat AlphaGo in the fourth game of the Google DeepMind Challenge. Playing as white, Lee won by resignation after 180 moves. AlphaGo held a strong position for the first half of the game, but commentators noted that Lee Sedol played a brilliant move 78, followed by a mistake by AlphaGo at move 79. “Today’s game was another example of AlphaGo playing a very interesting, good game,” said English commentator Michael Redmond 9P. “However, move 78 by Lee Sedol was really brilliant — and enabled him to win.“ Song Taegon 9P, the Korean commentator, said that “It seems Lee Sedol can now read AlphaGo better and has a better understanding of how AlphaGo moves. For the 5th match, it will be a far closer battle than before since we know each better. Professional go players said that they became more interested in playing go after witnessing AlphaGo’s innovative moves. People started to rethink about moves that were previously regarded as undesirable or bad moves. AlphaGo can help us think outside of the box.“ As in the previous games in this match, Lee used up all of his time and two periods of byō-yomi overtime, playing nearly two hours on his last period. With the match score 3-1, AlphaGo has already secured victory in the Google DeepMind Challenge Match, but Sunday’s loss heightens the drama going into the final game, Game Five, which will be played on Tuesday, March 15 at 1pm KST.
photo (left): AlphaGo’s Demis Hassabis and David Silver review Game 4 with Michael Redmond 9P; photo by Chris Garlock. photo (right): Lee Sedol, courtesy Geordie Wood for Wired.
Click here for Michael Redmond’s Match 3 Game Highlights and here for the Match 4 Livestream commentary by Michel Redmond 9P with Chris Garlock. Click here for complete commentaries on games 1-4, as well as brief game highlights for each round.
The fifth and final game in the 5-game Lee Sedol-AlphaGo match will be Tuesday, March 15, 1P KST (Monday night 9p PST, midnight EST). The match will be livestreamed on DeepMind’s YouTube channel with commentary by Redmond and Garlock. And catch Myungwan Kim 9P’s commentary with Andrew Jackson starting at 10P PST on the AGA’s YouTube Channel.