4 ms·

alpha go wins by 1/4

• alanfalcon 9y ago
  Which, it bears repeating, is no different to AlphaGo than if it had won by 14 points—it is programmed only to win, not to give any preference to larger margins of win. And being so expert at reading the board, it will often sacrifice that margin of victory for even the smallest increase in overall win percentage, leading to many "close" games like this. That said, I totally appreciate Ke Jie actually taking one of these live matches to the bitter end so we could see the counting process play out.
  • paradite 9y ago
    I understand that margin of wining and chance of winning are two different goals for optimization, but I would expect them to positively correlated, i.e. if you are winning more, then you have higher chance of winning.
    • weavie 9y ago
      Not necessarily. If you are ahead in points you have a higher chance of winning by playing defensive moves and strengthening your position. When behind you need to play riskier moves which could win you a lot of points, but could also risk spreading yourself too thinly resulting in your complete decimation.
      • Someone 9y ago
        So, that means Ke Jie either didn't know he was losing, or didn't play to win at the end, or played brilliantly at the end, picking the optimal move every time?
        • weavie 9y ago
          From what I have heard Alpha Go was roughly 10 points ahead by the end game, but didn't then bother maintaining the lead. In other words, it was aiming for a 0.5 point lead. Ke Jie would have known he was losing, it is a credit to him that he pushed through to the end so we could all marvel at the spectacle.
          • chj 9y ago
            > but didn't then bother maintaining the lead How did you know that?
            • namarie 9y ago
              Because it lost points by playing sub-optimally.
              • inverse_pi 9y ago
                exactly. In fact, I was really surprised when I saw B9. It could have played at B11 which was a 15 point move. But it decided to play safe because B11 even though big in point, would give back strong safe in the center. (it also lost 2 point ish in end game which is typical of Master)
                • platz 9y ago
                  maybe it's willing to loose points to erase uncertainty. Lee said AG took a smaller position on the top, eating the two stones, in order to simplify.
              • jhall1468 9y ago
                Incorrect. It lost points by focusing its play only on the probability of winning. It's moves were not "sub-optimal", its moves increased the likelihood that it would win by something. That, to humans, may look like sub-optimal play, but in reality it's the same way it was playing the entire time. By giving up points, it increased the chances of winning (because the points it gave up would never actually add up to a loss, but removed possibilities that could result in a loss).
    • taneq 9y ago
      Racing is about crossing the finish line first, so a racecar would always choose to go faster rather than slower, right? Actually if you're in the last lap (or few laps in a longer race) and you have a healthy lead, it's common to back off the pace a bit and sacrifice some of that lead in order to reduce your chances of a crash or mechanical failure.
  • 21 9y ago
    Maybe he wanted to see how AlphaGo plays the final moves.