Lee Sedol-AlphaGo, game 5. One can see that at move 70. G14 made by AlphaGo the G16 stone is cut off. The invasion at G16, move 69, was pretty deep but black could have followed up at 71. F15 for necessary protection. However, Lee as black chose to gamble and go in deeper at 71. AlphaGo then cut off the two invasive stones from supporting black stones at left, as the video diagram shows.
See at 14:24 of https://www.youtube.com/watch?v=sxL6uLhDDTE
This I think was the decisive point of the game.
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Lee Sedol-AlphaGo, game 5. One can see that at move 70. G14 made by AlphaGo the G16 stone is cut off. The invasion at G16, move 69, was pretty deep but black could have followed up at 71. F15 for necessary protection. However, Lee as black chose to gamble and go in deeper at 71. AlphaGo then cut off the two invasive stones from supporting black stones at left, as the video diagram shows.
See at 14:24 of https://www.youtube.com/watch?v=sxL6uLhDDTE
This I think was the decisive point of the game.
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