This may look like a seki, but notice what happens after white plays 'a' and 'b'. Black suddenly has one liberty, so he dies. Of course, black could play 'c' at any point before white gets 'a' and 'b', but then black is left with a dead shape inside, so he's dead.
You're right. In my hurry to read it out and put a full solution together, I was too hasty. Thanks.
This may look like a seki, but notice what happens after white plays 'a' and 'b'. Black suddenly has one liberty, so he dies. Of course, black could play 'c' at any point before white gets 'a' and 'b', but then black is left with a dead shape inside, so he's dead.
Thanks for the solution. It would make a good life or death problem.
I find more and more that my battles on the board reflect my battles off of it.
I perhaps wasn't being clear enough by what I meant as "silly".
To put it into words, the MCTS algorithm results in "make the move that has a higher probability of winning than other moves". But if the probability of winning for all moves is close to zero then the differences between these probabilities are also close to zero and there is no way for the algorithm to distinguish between "hopeless, but not making things worse" and "hopeless and making things worse".
That is why important to always allow these programs to resign. It's not so much that the program has concluded "can't win the game" but also "I can't distinguish between sensible and ridiculous moves". In other words, the MCTS algorithm doesn't work in this region.
If you have experience playing against these programs you will note that a human might resign earlier. Toward the end of a game that it will lose the program will make "insulting" attacks, play moves that will work only if responded against very poorly or not at all. The reason is that from its calculation the probability of that isn't zero. With experience playing against these programs you will learn to recognize when close to the end of the game whether the program "thinks" it will win or lose. Unnecessary safety moves that cost a point or two means the program has the game in hand while attacks that would work only against a bad mistake means the program "knows" it has lost.
Mike Novack wrote:If you have experience playing against these programs you will note that a human might resign earlier. Toward the end of a game that it will lose the program will make "insulting" attacks, play moves that will work only if responded against very poorly or not at all. The reason is that from its calculation the probability of that isn't zero. With experience playing against these programs you will learn to recognize when close to the end of the game whether the program "thinks" it will win or lose. Unnecessary safety moves that cost a point or two means the program has the game in hand while attacks that would work only against a bad mistake means the program "knows" it has lost.
To echo what oren said...I don't think it's only computers that do this (=